Physical interventions to interrupt or reduce the spread of respiratory viruses

Abstract

Background

Viral epidemics or pandemics of acute respiratory infections (ARIs) pose a global threat. Examples are influenza (H1N1) caused by the H1N1pdm09 virus in 2009, severe acute respiratory syndrome (SARS) in 2003, and coronavirus disease 2019 (COVID‐19) caused by SARS‐CoV‐2 in 2019. Antiviral drugs and vaccines may be insufficient to prevent their spread. This is an update of a Cochrane Review last published in 2020. We include results from studies from the current COVID‐19 pandemic.

Objectives

To assess the effectiveness of physical interventions to interrupt or reduce the spread of acute respiratory viruses.

Search methods

We searched CENTRAL, PubMed, Embase, CINAHL, and two trials registers in October 2022, with backwards and forwards citation analysis on the new studies.

Selection criteria

We included randomised controlled trials (RCTs) and cluster‐RCTs investigating physical interventions (screening at entry ports, isolation, quarantine, physical distancing, personal protection, hand hygiene, face masks, glasses, and gargling) to prevent respiratory virus transmission.

Data collection and analysis

We used standard Cochrane methodological procedures.

Main results

We included 11 new RCTs and cluster‐RCTs (610,872 participants) in this update, bringing the total number of RCTs to 78. Six of the new trials were conducted during the COVID‐19 pandemic; two from Mexico, and one each from Denmark, Bangladesh, England, and Norway. We identified four ongoing studies, of which one is completed, but unreported, evaluating masks concurrent with the COVID‐19 pandemic. Many studies were conducted during non‐epidemic influenza periods. Several were conducted during the 2009 H1N1 influenza pandemic, and others in epidemic influenza seasons up to 2016. Therefore, many studies were conducted in the context of lower respiratory viral circulation and transmission compared to COVID‐19. The included studies were conducted in heterogeneous settings, ranging from suburban schools to hospital wards in high‐income countries; crowded inner city settings in low‐income countries; and an immigrant neighbourhood in a high‐income country. Adherence with interventions was low in many studies. The risk of bias for the RCTs and cluster‐RCTs was mostly high or unclear. Medical/surgical masks compared to no masks We included 12 trials (10 cluster‐RCTs) comparing medical/surgical masks versus no masks to prevent the spread of viral respiratory illness (two trials with healthcare workers and 10 in the community). Wearing masks in the community probably makes little or no difference to the outcome of influenza‐like illness (ILI)/COVID‐19 like illness compared to not wearing masks (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.84 to 1.09; 9 trials, 276,917 participants; moderate‐certainty evidence. Wearing masks in the community probably makes little or no difference to the outcome of laboratory‐confirmed influenza/SARS‐CoV‐2 compared to not wearing masks (RR 1.01, 95% CI 0.72 to 1.42; 6 trials, 13,919 participants; moderate‐certainty evidence). Harms were rarely measured and poorly reported (very low‐certainty evidence). N95/P2 respirators compared to medical/surgical masks We pooled trials comparing N95/P2 respirators with medical/surgical masks (four in healthcare settings and one in a household setting). We are very uncertain on the effects of N95/P2 respirators compared with medical/surgical masks on the outcome of clinical respiratory illness (RR 0.70, 95% CI 0.45 to 1.10; 3 trials, 7779 participants; very low‐certainty evidence). N95/P2 respirators compared with medical/surgical masks may be effective for ILI (RR 0.82, 95% CI 0.66 to 1.03; 5 trials, 8407 participants; low‐certainty evidence). Evidence is limited by imprecision and heterogeneity for these subjective outcomes. The use of a N95/P2 respirators compared to medical/surgical masks probably makes little or no difference for the objective and more precise outcome of laboratory‐confirmed influenza infection (RR 1.10, 95% CI 0.90 to 1.34; 5 trials, 8407 participants; moderate‐certainty evidence). Restricting pooling to healthcare workers made no difference to the overall findings. Harms were poorly measured and reported, but discomfort wearing medical/surgical masks or N95/P2 respirators was mentioned in several studies (very low‐certainty evidence). One previously reported ongoing RCT has now been published and observed that medical/surgical masks were non‐inferior to N95 respirators in a large study of 1009 healthcare workers in four countries providing direct care to COVID‐19 patients. Hand hygiene compared to control Nineteen trials compared hand hygiene interventions with controls with sufficient data to include in meta‐analyses. Settings included schools, childcare centres and homes. Comparing hand hygiene interventions with controls (i.e. no intervention), there was a 14% relative reduction in the number of people with ARIs in the hand hygiene group (RR 0.86, 95% CI 0.81 to 0.90; 9 trials, 52,105 participants; moderate‐certainty evidence), suggesting a probable benefit. In absolute terms this benefit would result in a reduction from 380 events per 1000 people to 327 per 1000 people (95% CI 308 to 342). When considering the more strictly defined outcomes of ILI and laboratory‐confirmed influenza, the estimates of effect for ILI (RR 0.94, 95% CI 0.81 to 1.09; 11 trials, 34,503 participants; low‐certainty evidence), and laboratory‐confirmed influenza (RR 0.91, 95% CI 0.63 to 1.30; 8 trials, 8332 participants; low‐certainty evidence), suggest the intervention made little or no difference. We pooled 19 trials (71, 210 participants) for the composite outcome of ARI or ILI or influenza, with each study only contributing once and the most comprehensive outcome reported. Pooled data showed that hand hygiene may be beneficial with an 11% relative reduction of respiratory illness (RR 0.89, 95% CI 0.83 to 0.94; low‐certainty evidence), but with high heterogeneity. In absolute terms this benefit would result in a reduction from 200 events per 1000 people to 178 per 1000 people (95% CI 166 to 188). Few trials measured and reported harms (very low‐certainty evidence). We found no RCTs on gowns and gloves, face shields, or screening at entry ports.

Authors' conclusions

The high risk of bias in the trials, variation in outcome measurement, and relatively low adherence with the interventions during the studies hampers drawing firm conclusions. There were additional RCTs during the pandemic related to physical interventions but a relative paucity given the importance of the question of masking and its relative effectiveness and the concomitant measures of mask adherence which would be highly relevant to the measurement of effectiveness, especially in the elderly and in young children. There is uncertainty about the effects of face masks. The low to moderate certainty of evidence means our confidence in the effect estimate is limited, and that the true effect may be different from the observed estimate of the effect. The pooled results of RCTs did not show a clear reduction in respiratory viral infection with the use of medical/surgical masks. There were no clear differences between the use of medical/surgical masks compared with N95/P2 respirators in healthcare workers when used in routine care to reduce respiratory viral infection. Hand hygiene is likely to modestly reduce the burden of respiratory illness, and although this effect was also present when ILI and laboratory‐confirmed influenza were analysed separately, it was not found to be a significant difference for the latter two outcomes. Harms associated with physical interventions were under‐investigated. There is a need for large, well‐designed RCTs addressing the effectiveness of many of these interventions in multiple settings and populations, as well as the impact of adherence on effectiveness, especially in those most at risk of ARIs.

Summary of findings

Background

Description of the condition

Epidemic and pandemic viral infections pose a serious threat to people worldwide. Epidemics of note include severe acute respiratory syndrome (SARS) in 2003 and the Middle East respiratory syndrome (MERS), which began in 2012, and the current SARS‐CoV‐2 pandemic. Major pandemics include the H1N1 influenza caused by the H1N1pdm09 virus in 2009 and the coronavirus disease 2019 (COVID‐19) caused by SARS‐CoV‐2.

Even non‐epidemic acute respiratory infections (ARIs) place a huge burden on healthcare systems around the world, and are a prominent cause of morbidity (WHO 2017). Furthermore, ARIs are often antecedents to lower respiratory tract infections (RTIs) caused by bacterial pathogens (i.e. pneumonia), which cause millions of deaths worldwide, mostly in low‐income countries (Schwartz 2018).

High viral load, high levels of transmissibility, susceptible populations, and symptomatic patients are considered to be the drivers of such epidemics and pandemics (Jefferson 2006a). Preventing the spread of respiratory viruses from person to person may be effective at reducing the spread of outbreaks.

Physical interventions, such as the use of masks and physical distancing measures, might prevent the spread of respiratory viruses which are considered to be transmitted by multiple modes of transmission including by respiratory particles of varying sizes spreading from infected to susceptible people and through direct and indirect contact (Kutter 2018; Leung 2021). It is recognised that there is a continuum of respiratory particle sizes varying between large droplet to fine aerosols, which is an important concept. Particles of a variety of sizes may be expelled from the human airway during coughing, sneezing, singing, talking, and during certain medical procedures (WHO 2021). In addition, transmission of respiratory viruses is likely highly complex, dependent on multiple host, virus and environmental factors, plus the myriad of interactions between these factors, which may influence the predominant modes of transmission in any given setting (Broderick 2008; Hendley 1988; Kutter 2018; Leung 2021). Current evidence suggests that the virus responsible for the current COVID‐19 pandemic spreads mainly between people who are in close contact with each other (Onakpoya 2022a).

It is also unknown if all respiratory viruses or different strains of a specific respiratory virus transmit in a similar manner, further adding to the complexity of respiratory virus transmission.

Description of the intervention

Single measures of intervention such as the use of vaccines or antivirals, may be insufficient to contain the spread of influenza, but combinations of interventions may reduce the reproduction number to below 1 (Demicheli 2018a; Demicheli 2018b; Jefferson 2014; Jefferson 2018; Thomas 2010). When the reproduction number (or R0) is below 1, each infection causes less than one new secondary infection and the disease will eventually die out. For some respiratory viruses there are no licensed interventions, and a combination of social and physical interventions may be the only option to reduce the spread of outbreaks, particularly those that may be capable of becoming epidemic or pandemic in nature (Luby 2005). Such interventions were emphasised in the World Health Organization's latest Global Influenza Strategy 2019 to 2030, and have several possible advantages over other methods of suppressing ARI outbreaks since they may be instituted rapidly and may be independent of any specific type of infective agent, including novel viruses. In addition, the possible effectiveness of public health measures during the Spanish flu pandemic of 1918 to 1919 in US cities supports the impetus to investigate the existing evidence on the effectiveness of such interventions (Bootsma 2007), including quarantine (such as isolation, physical distancing) and the use of disinfectants. We also considered the major societal implications for any community adopting these measures (CDC 2005a; CDC 2005b; WHO 2006b; WHO 2020a; WHO 2020b).

How the intervention might work

Epidemics and pandemics are more likely during antigenic change (changes in the viral composition) in the virus or transmission from animals (domestic or wild) when there is no natural human immunity (Bonn 1997). High viral load, high levels of transmissibility, and symptomatic patients are considered to be the drivers of such epidemics and pandemics (Jefferson 2006b).

Physical interventions, such as the use of masks (Greenhalgh 2020; Howard 2020), physical distancing measures, school closures, and limitations of mass gatherings, might prevent the spread of the virus transmitted by infectious respiratory particles from infected to susceptible individuals. The use of hand hygiene, gloves, and protective gowns can also prevent the spread by limiting the transfer of viral particles onto and from fomites (inanimate objects such as flat surfaces, tabletops, utensils, porous surfaces, or nowadays cell phones, which can transmit the agent if contaminated) (Onakpoya 2022b). Such public health measures were widely adopted during the Spanish flu pandemic and have been the source of considerable debate (Bootsma 2007).

Why it is important to do this review

Although the benefits of physical interventions seem self‐evident, given the global importance of interrupting respiratory virus transmission, having up‐to‐date estimates of their effectiveness is necessary to inform planning, decision‐making, and policy. The continuance of outbreaks of COVID‐19 and the reporting of several new trials assessing different barrier interventions in preventing the spread of SARS‐COV‐2 virus, have prompted this update (WHO 2022). Physical methods have several possible advantages over other methods of suppressing ARI outbreaks, including their rapid deployment and ability to be independent of the infective agent, including novel viruses.

The hallmark of the 2020 update was shifting from including all types of studies to a focus on randomised controlled trials (RCTs) only, which had substantially increased in number. This change enabled more robust evidence summaries from high‐quality studies, which are much less prone to the risk of the multiple biases associated with observational studies, to help policy and decision makers in making national and global recommendations. The 2020 update identified 67 relevant studies, but none were carried out during the COVID‐19 pandemic (Jefferson 2020). The three key messages of that update were: (1) hand hygiene programmes may help to slow the spread of respiratory viruses; (2) uncertainty whether wearing masks or N95/P2 respirators would help in slowing the spread of respiratory viruses; and (3) few studies were identified for other interventions. One study looked at quarantine, and none looked at eye protection, gowns and gloves, or screening people when they entered a country. However, during the last search of the 2020 update, six ongoing, unpublished studies were identified; three of them evaluate masks in COVID‐19. The review authors are aware that several trials have now been published since the publication of the 2020 update, warranting this new update.

This is the fifth update (Jefferson 2009; Jefferson 2010; Jefferson 2011; Jefferson 2020) of a Cochrane Review first published in 2007 (Jefferson 2007).

Objectives

To assess the effectiveness of physical interventions to interrupt or reduce the spread of acute respiratory viruses.

Methods

Criteria for considering studies for this review

Types of studies

For this 2022 update we only considered individual‐level randomised controlled trials (RCTs), or cluster‐RCTs, or quasi‐RCTs for inclusion.

In versions of this review prior to 2020 we also included observational studies (cohorts, case‐controls, before‐after, and time series studies). However, for this update there were sufficient randomised studies to address our study aims, so we excluded observational studies because randomisation is the optimal method to prevent systematic differences between participants in different intervention groups and, further, deciding who receives an intervention and who does not is influenced by many factors, including prognostic factors (Higgins 2011). This point is particularly relevant here because individuals who chose to implement physical interventions are likely to use multiple interventions, thus making it difficult to separate out the effect of single interventions. Further, they are likely to be different from individuals who do not implement physical interventions in ways that are difficult to measure.

Types of participants

People of all ages.

Types of interventions

We included RCTs and cluster‐RCTs of trials investigating physical interventions or combinations of interventions to prevent respiratory virus transmission compared with doing nothing or with other interventions. The interventions of interest included: screening at entry ports, isolation, quarantine, physical distancing, personal protection (clothing, gloves, devices), hand hygiene, face masks, gargling, nasal washes, eye protective devices, face shields, disinfecting, and school closure.

Types of outcome measures

For the outcomes listed below we had no predetermined key time points of interest or adverse events of special interest, however, methods of assessment of cases of viral respiratory illness based on laboratory‐confirmation needed to be based on an accurate test in combination with critical additional information. For example, a polymerase chain reaction (PCR) test in combination with symptoms of disease, or a serological test at baseline as well as at the end of follow‐up were acceptable methods. Further, we stratified analyses by study‐specific definitions for cases of viral respiratory illness which included a broad definition of acute respiratory infection (ARI), a more specific definition of influenza‐like‐illness (ILI), and the most precise definition of a laboratory‐confirmed respiratory infection that identified the actual viral pathogen. For the studies conducted during the COVID‐19 pandemic, we assumed that COVID‐like illness was interchangeable with ILI. In the case of laboratory‐confirmed respiratory infection we separated out SARS‐CoV‐2/influenza and other viral pathogens. We did not pool these outcomes as it cannot be assumed that the effects of physical interventions will be the same for the different viral pathogens. The one exception was for the comparison of hand‐hygiene versus control where the estimated effects for ARI, ILI and laboratory‐confirmed infection were highly consistent.

Primary outcomes

Numbers of cases of viral respiratory illness (including acute respiratory infections (ARI), influenza‐like illness (ILI), COVID‐like illness and laboratory‐confirmed influenza, SARS‐CoV‐2 or other viral pathogens).Adverse events related to the intervention.

Secondary outcomes

Deaths.Severity of viral respiratory illness as reported in the studies.Absenteeism.Hospital admissions.Complications related to the illness, e.g. pneumonia.

Search methods for identification of studies

Electronic searches

For this 2022 update, we refined the original search strategy using a combination of previously included studies and automation tools (Clark 2020). We converted this search using the Polyglot Search Translator (Clark 2020), and ran the searches in the following databases:

the Cochrane Central Register of Controlled Trials (CENTRAL) (2022, Issue 09), which includes the Acute Respiratory Infections Group's Specialised Register (searched 04 October 2022) (Appendix 1);PubMed (01 January 2020 to 04 October 2022) (Appendix 2);Embase (01 January 2020 to 04 October 2022) (Appendix 3);CINAHL (Cumulative Index to Nursing and Allied Health Literature) (01 January 2020 to 04 October) (Appendix 4);US National Institutes of Health Ongoing Trials Register ClinicalTrials.gov (January 2010 to 04 October 2022); andWorld Health Organization International Clinical Trials Registry Platform (January 2010 to 04 October 2022).

We combined the database searches with the Cochrane Highly Sensitive Search Strategy for identifying randomised trials in MEDLINE: sensitivity‐ and precision‐maximising version (2008 revision) (Lefebvre 2011). Details of previous searches are available in Appendix 5.

Searching other resources

We conducted a backwards‐and‐forwards citation analysis in Scopus on all newly included studies to identify other potentially relevant studies.

Data collection and analysis

Selection of studies

The search and citation analysis results were initially screened via the RobotSearch tool (Marshall 2018) to exclude all studies that were obviously not RCTs. We scanned the titles and abstracts of studies identified by the searches. We obtained the full‐text articles of studies that either appeared to meet our eligibility criteria or for which there was insufficient information to exclude it. We then used a standardised form to assess the eligibility of each study based on the full article.

Data extraction and management

Five review authors (LA/GB/EF/EB/TOJ) independently applied the inclusion criteria to all identified and retrieved articles, and extracted data using a standard template that had been developed for and applied to previous versions of the review, but was revised to reflect our focus on RCTs and cluster‐RCTs for this update. We resolved any disagreements through discussion with either PG or JMC acting as arbiter. We extracted and reported descriptions of interventions using the Template for Intervention Description and Replication (TIDieR) template (Table 4).

Assessment of risk of bias in included studies

Four review authors (EF/EB/GB/MJ) independently assessed risk of bias for the method of random sequence generation and allocation concealment (selection bias), blinding of participants and personnel (performance bias), blinding of outcome assessment (detection bias), outcome reporting (attrition bias), and selective reporting (reporting bias). In addition, for the cluster trials, we assessed selection bias due to how recruitment of participants was conducted. Participants should be identified before the cluster is randomised or, if not, recruitment should be by someone masked to the cluster allocation. Further, we considered whether there were sufficient numbers of clusters in each treatment group to ensure comparable groups, and excluded one study from the analysis due to insufficient number of clusters. We used the Cochrane risk of bias tool to assess risk of bias, classifying each risk of bias domain as 'low', ‘high’, or ‘unclear’. The following were indications for low risk of bias:

method of random sequence generation: the method was well‐described and is likely to produce balanced and truly random groups;allocation concealment: the next treatment allocation was not known to participant/cluster or treating staff until after consent to join the study;blinding of participants and personnel: the method is likely to maintain blinding throughout the study;blinding of outcome assessors: all outcome assessors were unaware of treatment allocation;outcome reporting: participant attrition throughout the study is reported, and reasons for loss are appropriately described; andselective reporting: all likely planned and collected outcomes have been reported.

Measures of treatment effect

When possible, we performed meta‐analysis and summarised effectiveness as risk ratio (RR) using 95% confidence intervals (CIs). For studies that could not be pooled, we used the effect measures reported by the trial authors (such as RR or incidence rate ratio (IRR) with 95% CI or, when these were not available, relevant P values). Where multiple analyses were reported on the same outcome we chose the analysis based on preferences for: (1) an adjusted analysis (over an unadjusted analysis), and (2) an analysis based on a longer follow‐up period, or a greater number of outcomes events.

Unit of analysis issues

Many of the included studies were cluster‐RCTs. To avoid any unit of analysis issues, we only included treatment effect estimates that were based on methods that were appropriate for the analysis of cluster trials, such as mixed models and generalised estimating equations. Given this restriction, we used the generalised inverse‐variance method of meta‐analysis. Some cluster‐RCTs that did not report cluster‐adjusted treatment effects provided sufficient data (number of events and participants by treatment group and intraclass correlations) for us to calculate appropriate treatment effect estimates and standard errors using the methods described in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2021a). For studies with multiple treatment groups but only one control group, where appropriate, we adjusted standard errors upwards to avoid unit of analysis errors in the meta‐analyses. We did this by splitting the control group into equal sized groups and adjusting standard errors upwards to account for the reduced sample size of the control subgroups (Higgins 2021b).

Dealing with missing data

Previously, whenever details of studies were unclear, or studies were only known to us by abstracts or communications at meetings, we corresponded with first or corresponding authors. For this 2022 review, we did not contact authors of studies.

Assessment of heterogeneity

Aggregation of data was dependent on types of comparisons, sensitivity and homogeneity of definitions of exposure, populations and outcomes used. We calculated the I²statistic and Chi² test for each pooled estimate to assess the presence of statistical heterogeneity (Higgins 2002; Higgins 2003).

Assessment of reporting biases

Given the widely disparate nature of our evidence base, we limited our assessment of possible reporting biases to funnel plot visual inspection if we had > 10 included studies for any single meta‐analysis.

Data synthesis

If possible and appropriate, we combined studies in a meta‐analysis. We used the generalised inverse‐variance random‐effects model where cluster‐RCTs were included in the analysis. We chose the random‐effects model because we expected clinical heterogeneity due to differences in pooled interventions and outcome definitions, and methodological heterogeneity due to pooling of RCTs and cluster‐RCTs.

Subgroup analysis and investigation of heterogeneity

We conducted one post hoc subgroup analyses of adults (18 years +) versus children (0 to 18 years) for the comparison of hand hygiene versus control.

We did not conduct further investigation of heterogeneity due to insufficient numbers of studies included in the comparisons.

Sensitivity analysis

We conducted a sensitivity analysis for hand hygiene versus control where we included the most precise and unequivocal measure of viral respiratory illness reported for each included study.

Summary of findings and assessment of the certainty of the evidence

We created three summary of findings tables using the following outcomes: numbers of cases of viral respiratory illness (including ARIs, ILI, COVID‐like illness and laboratory‐confirmed influenza/SARS‐CoV‐2 or other respiratory viruses), and adverse events related to the intervention (Table 1; Table 2; Table 3). We planned to include the secondary outcomes of deaths; severity of viral respiratory illness as reported in the studies; absenteeism; hospital admissions; and complications related to the illness (e.g. pneumonia). However, these data were poorly reported in the included studies. We used the five GRADE considerations (study limitations, consistency of effect, imprecision, indirectness, and publication bias) to assess the certainty of evidence as it related to the studies which contributed data to the meta‐analyses for the prespecified outcomes (Atkins 2004). We used the methods and recommendations described in Section 8.5 and Chapter 12 of the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011), employing GRADEpro GDT software (GRADEpro GDT). We justified all decisions to down‐ or upgrade the certainty of the evidence in footnotes, and made comments to aid the reader's understanding of the review where necessary.

Results

Description of studies

See Characteristics of included studies and Characteristics of excluded studies tables. Five trials were funded by government and pharmaceutical companies (Aiello 2010; Aiello 2012; Chard 2019; Yeung 2011; Zomer 2015), and nine trials were funded by pharmaceutical companies (Arbogast 2016; Carabin 1999; Luby 2005; Nicholson 2014; Sandora 2005; Sandora 2008; Turner 2004a; Turner 2004b; Turner 2012).

Results of the search

For this 2022 update we found 2667 records through database and trial registry searching, as well as 738 record through citation searching. After removing duplicates we had 2936 records that underwent title and abstract screening. 
We identified a total of 202 titles in this 2022 update. We excluded 180 titles and retrieved the full papers of 35 studies, to include 11 new studies. See Figure 1.

1 Study flow diagram. (Figure not reproduced here; see the original article.)

Included studies

In this 2022 update we included 11 new studies (610,872 participants); randomised controlled trials (RCTs) (n = 5) or cluster‐RCTs (n = 6) published between 2020 and 2022. In total 78 studies are included in this review update. For detailed descriptions of the interventions of the included studies, see Table 4.

Eighteen trials focused on using masks (Abaluck 2022; Aiello 2010; Aiello 2012; Alfelali 2020; Barasheed 2014; Bundgaard 2021; Canini 2010; Cowling 2008; Ide 2016; Jacobs 2009; Loeb 2009; MacIntyre 2009; MacIntyre 2011; MacIntyre 2013; MacIntyre 2015; MacIntyre 2016; Radonovich 2019; Suess 2012). Thirteen of the 18 trials compared medical/surgical masks to no mask (control) (Abaluck 2022; Aiello 2010; Aiello 2012; Alfelali 2020; Barasheed 2014; Bundgaard 2021; Canini 2010; Cowling 2008; Jacobs 2009; MacIntyre 2009; MacIntyre 2015; MacIntyre 2016; Suess 2012). One study compared catechin‐treated masks to no mask (Ide 2016), and one study included cloth masks versus control (third arm in MacIntyre 2015). Three of the 18 trials were in healthcare workers (Ide 2016; Jacobs 2009; MacIntyre 2015), whilst the remaining trials were in non‐healthcare workers (students, households, families, or pilgrims). Only one trial was conducted during the H1N1 pandemic season (Suess 2012), and two trials were conducted during the SARS‐CoV‐2 pandemic (Abaluck 2022; Bundgaard 2021).

Five of the 18 trials compared N95 masks or P2 masks to medical/surgical masks (Loeb 2009; MacIntyre 2009; MacIntyre 2011; MacIntyre 2013; Radonovich 2019). All of these trials, except for one study that was conducted on household individuals (MacIntyre 2009), included healthcare workers either in a hospital setting, Loeb 2009; MacIntyre 2011; MacIntyre 2013, or an outpatient setting (MacIntyre 2009; Radonovich 2019).

One trial evaluated the effectiveness of quarantining workers of one of two sibling companies in Japan whose family members had developed an influenza‐like illness (ILI) during the 2009 to 2010 H1N1 influenza pandemic (Miyaki 2011). Another trial conducted during the SARS‐CoV‐2 pandemic in Norway investigated fitness centre access with physical distancing compared to no access (Helsingen 2021); and one cluster trial compared daily testing for contacts of individuals with SARS‐CoV‐2 compared to self‐isolation at home in English secondary schools (Young 2021).

Nineteen trials compared hand hygiene interventions with no hand hygiene (control) and provided data suitable for meta‐analysis. The populations in these trials included adults, children, and families, in settings such as schools (Biswas 2019; Stebbins 2011), childcare centres (Azor‐Martinez 2018; Correa 2012; Roberts 2000; Zomer 2015), homes/households (Cowling 2008; Cowling 2009; Larson 2010; Little 2015; Nicholson 2014; Ram 2015; Sandora 2005; Simmerman 2011), offices (Hubner 2010), military trainees (Millar 2016), villages (Ashraf 2020; Swarthout 2020), and nursing homes (Teesing 2021). None of the trials were conducted during a pandemic, although some of the studies were conducted during peak influenza seasons.

A further 10 trials that compared a variety of hand hygiene modalities to control provided insufficient information to include in meta‐analyses. Three trials were in children: one was conducted in daycare centres in Denmark examining a multimodal hygiene programme (Ladegaard 1999), and two trials compared a hand hygiene campaign or workshop in an elementary school environment in Saudi Arabia, Alzaher 2018, and Egypt, Talaat 2011. Three trials tested virucidal hand treatment in an experimental setting, Gwaltney 1980; Turner 2004a, and in a community, Turner 2012, in the USA. Feldman 2016 compared hand‐washing with chlorhexidine gluconate amongst Israeli sailors. One trial compared hand sanitiser packaged in a multimodal hygiene programme amongst office employees in the USA (Arbogast 2016). Two trials were conducted in a long‐term facility setting: one trial examined the effect of a bundled hand hygiene programme on infectious risk in nursing home residents in France (Temime 2018), and the other trial compared the effect of using hand sanitisers in healthcare workers on the rate of infections (including respiratory infections) in nursing home residents in Hong Kong (Yeung 2011).

Five trials compared different hand hygiene interventions in a variety of settings such as schools (Morton 2004, in kindergartens and elementary schools in the USA; Priest 2014, in primary schools in New Zealand; and Pandejpong 2012 in kindergartens in Thailand). One study was conducted in low‐income neighbourhoods in Karachi, Pakistan (Luby 2005), and one was conducted in a workplace environment in Finland (Savolainen‐Kopra 2012). A variety of interventions were used across these trials such as soap and water (Luby 2005; Savolainen‐Kopra 2012), hand sanitiser (Morton 2004; Pandejpong 2012; Priest 2014; Savolainen‐Kopra 2012), body wash (Luby 2005), and alcohol‐based hand wipes (Morton 2004), with or without additional hygiene education. There was considerable variation in interventions, and the information in the trial reports was insufficient to permit meta‐analysis.

Seven trials compared a combined intervention of hand hygiene and face masks with control. Four of these trials were carried out in households in Germany (Suess 2012), Thailand (Simmerman 2011), Hispanic immigrant communities in the USA (Larson 2010), and households in Hong Kong (Cowling 2009). Two trials were conducted amongst university student residences (Aiello 2010; Aiello 2012), and two trials in groups of pilgrims at the annual Hajj (Aelami 2015; Alfelali 2020). Moreover, six trials evaluated the incremental benefit of combining surgical masks in addition to hand hygiene with soap (Simmerman 2011), hand sanitiser (Aiello 2010; Aiello 2012; Larson 2010; Suess 2012), or both (Cowling 2009), versus mask or hand hygiene alone on the outcomes of ILI and influenza. Aelami 2015 investigated a hygienic package (alcohol‐based hand rub (gel or spray), surgical masks, soap, and paper handkerchiefs) with a control group.

Seven trials compared a multimodal combination of hand hygiene and disinfection of surfaces, toys, linen, or other components of the environment with a control (Ban 2015; Carabin 1999; Ibfelt 2015; Kotch 1994; McConeghy 2017; Sandora 2008; White 2001). Variation in scope and type of interventions and insufficient data in trial reports precluded meta‐analysis. All studies except for one were in children (McConeghy 2017), which was in a nursing home population).

Three trials included in two papers investigated the role of virucidal tissues in interrupting transmission of naturally occurring respiratory infections in households (Farr 1988a; Farr 1988b; Longini 1988). Four cluster‐RCTs implemented complex, multimodal sanitation, education, cooking, and hygiene interventions (Chard 2019; Hartinger 2016; Huda 2012; Najnin 2019). All four of these trials were conducted in low‐income countries in settings with minimal to no access to basic sanitation.

Three trials assessed the effect of gargling on the incidence of upper respiratory tract infections (URTIs) or influenza: gargling with povidone‐iodine (Satomura 2005), green tea (Ide 2014), and tap water (Goodall 2014). Two trials investigated the use of mouth/nasal washes on the incidence of SARS‐CoV‐2 infection in healthcare workers during the COVID‐19 pandemic (Almanza‐Reyes 2021; Gutiérrez‐García 2022). One trial investigated the use of glasses against the transmission of SARS‐CoV‐2 (Fretheim 2022a).

Ongoing studies

We identified four ongoing studies during the course of the COVID‐19 pandemic, of which one is completed, but unreported (NCT04471766). The trials evaluated masks concurrent with the COVID‐19 pandemic. Three trials on other interventions are ongoing (Brass 2021; NCT03454009; NCT04267952).

Studies awaiting classification

We identified five studies awaiting classification (Contreras 2022; Croke 2022; Delaguerre 2022; Loeb 2022; Varela 2022).

A previous RCT (NCT04296643) reported as ongoing in the last version has now been recently published but was not able to be included in the summary of findings pooled results (Loeb 2022). In a multicentre, randomised non‐inferiority trial of 1009 healthcare workers (HCWs) across four countries randomised to medical mask versus fit‐tested N95 respirators for direct care of COVID‐19 patients or long‐term care residents, laboratory‐confirmed SARS‐CoV‐2 was found in 10.46% (52/497) versus 9.27% (47/507) in the medical/surgical mask group and fit‐tested N95 respirator group (hazard ratio 1.14 (95% CI 0.77 to 1.69), respectively. There was a 1.19% absolute increase in risk of COVID‐19 with medical masks versus N95 respirator  95% CI (‐2.5% to 4.9%). There were 47 (10.8%) adverse events related to the intervention reported in the medical mask group and 59 (13.6%) in the N95 respirator group. The use of medical masks was found to be non‐inferior to N95 respirators in the direct care of COVID‐19 patients and the study crossed over into the more transmissible Omicron variant period of the COVID‐19 pandemic.

Excluded studies

We excluded a total of 180 studies. We identified 20 new studies for exclusion at the data extraction stage of this 2022 update, all of which appeared to be eligible at screening. Five of the 20 studies were ineligible due to evaluating treatments for patients with disease (Cyril Vitug 2021; Ferrer 2021; Meister 2022; Sanchez Barrueco 2022; Sevinc Gul 2022), two were excluded because they did not assess clinical outcomes (Costa 2021; Seneviratne 2021), four were excluded due to not assessing viral outcomes (Gharebaghi 2020; Giuliano 2021; Karakaya 2021; Kawyannejad 2020), five were excluded as they were experiments that did not measure any of our outcomes of interest (Ahmadian 2022; Dalakoti 2022; Egger 2022; Malaczek 2022; Montero‐Vilchez 2022); three were excluded because they were not RCTs (Chen 2022; Lim 2022; Mo 2022), and one was excluded as it was a report of another study (Munoz‐Basagoiti 2022).

Risk of bias in included studies

The overall risk of bias is presented graphically in Figure 2 and summarised by included study in Figure 3. Details on the judgements can be found in the descriptions of individual included studies (Characteristics of included studies table). Out of 78 included studies, only two were rated as low risk of bias for all domains. One of those studies compared two different types of masks (Radonovich 2019), and the other compared hand sanitiser to no treatment (Turner 2012). Notably, neither of these two studies was blinded, however, trial procedures were sufficiently robust that the risk of performance bias was low. Overall,approximately only 20% of the studies were rated as low risk of performance bias. This risk of bias domain was particularly problematic because most interventions studied could not be blinded from participants and/or investigators. The two risks of bias domains that were rated the least problematic were attrition bias and random sequence generation where around 50% of studies were rated as low risk of bias. Allocation concealment, blinded outcome assessment and selective reporting were rated as low risk of bias for around 40% of the included studies. Many of the included studies were cluster‐RCTs where the randomisation process was not well reported leading to ratings of unclear risk of bias.

2 'Risk of bias' graph: review authors' judgements about each risk of bias item presented as percentages across all included trials. (Figure not reproduced here; see the original article.)

3 'Risk of bias' summary: review authors' judgements about each risk of bias item for each included trial. (Figure not reproduced here; see the original article.)

Allocation

For this 2022 review, 10 of the 11 newly included studies provided adequate information on randomisation and were  judged to have low risk of bias (Abaluck 2022; Alfelali 2020; Almanza‐Reyes 2021; Ashraf 2020; Bundgaard 2021; Fretheim 2022a; Helsingen 2021; Swarthout 2020; Teesing 2021; Young 2021). Six of these studies described the use of a computerised random number generator (Almanza‐Reyes 2021; Bundgaard 2021; Helsingen 2021; Swarthout 2020; Teesing 2021; Young 2021). Almanza‐Reyes 2021 described the use of computer‐generated stratified block scheme, while Bundgaard 2021 reported the use of a computer algorithm stratified by the five regions of Denmark. In Fretheim 2022a, the investigators used a digital platform (Nettskjema) for recruitment, randomisation and allocation. Three studies mentioned the use of a random number generator, with no additional specifics (Helsingen 2021; Swarthout 2020; Teesing 2021), while Young 2021 mentioned that randomisation was performed in blocks of two and stratified using nine strata to ensure a sample representative of schools and colleges in England. Abaluck 2022 reported pairwise cross randomisation, whilst Ashraf 2020 reported using a block random number generator. Alfelali 2020 described using coin‐tossing by an individual who was not a member of the research team (i.e. a fellow pilgrim who was not a participant in the trial, a tour operator, or a medical volunteer). One study provided insufficient information to judge the sequence generation bias (Gutiérrez‐García 2022).

The success of randomisation was judged as low risk of bias in one study only that used an off‐site investigator to allocate groups (Ashraf 2020). Four new studies provided insufficient information to make a judgment on the adequacy of the process (Bundgaard 2021; Swarthout 2020; Teesing 2021; Young 2021). The remaining six newly included studies were judged as high risk of allocation bias (Abaluck 2022; Alfelali 2020; Almanza‐Reyes 2021; Fretheim 2022a; Gutiérrez‐García 2022; Helsingen 2021). In Abaluck 2022, there was a significant difference in the numbers of households included in each treatment group, suggestive of a lack of allocation concealment. Alfelali 2020 used coin tossing, which can lead to a large imbalance. In Almanza‐Reyes 2021 baseline prognostic factors (vaccination and frequency of handwashing) were unbalanced between the two arms. In Fretheim 2022a, a higher number of participants used face masks in the intervention group. In Gutiérrez‐García 2022 there as a significant age difference between the two groups. Helsingen 2021 described assigning the randomised sequence by a member of the research team, with no further description.

For the review published in 2020, information on sequence generation was overall poorly reported in most of the  included studies. Nineteen of the included studies provided adequate information on the randomisation scheme and were judged as at low risk of bias (Aiello 2012; Azor‐Martinez 2016; Azor‐Martinez 2018; Biswas 2019; Canini 2010; Correa 2012; Ide 2014; MacIntyre 2015; MacIntyre 2016; Millar 2016; Najnin 2019; Radonovich 2019; Ram 2015; Simmerman 2011; Stebbins 2011; Suess 2012; Talaat 2011; Turner 2012; Zomer 2015). Nine studies described the use of computerised sequence generation program/software (Aiello 2012; Azor‐Martinez 2018; Biswas 2019; Canini 2010; Millar 2016; Najnin 2019; Radonovich 2019; Talaat 2011; Turner 2012). One study used random number tables for sequence generation (Azor‐Martinez 2016). Three studies described using the random function in Microsoft Excel (Microsoft Excel 2018) (Correa 2012; MacIntyre 2016; Suess 2012). Two studies used statistical software to generate a randomisation allocation (MacIntyre 2015; Priest 2014). Two studies reported using block randomisation: Ram 2015 used block randomisation, and an independent investigator‐generated the list of random assignments, whilst Simmerman 2011 performed block randomisation. Stebbins 2011 used constrained randomisation, and Zomer 2015 reported using stratified randomisation by means of computer generation with a 1:1 ratio in each of the strata.

Fourteen studies reported insufficient information to permit a judgement on the adequacy of the process to minimise selection bias (Aelami 2015; Alzaher 2018; Arbogast 2016; Barasheed 2014; Chard 2019; DiVita 2011; Feldman 2016; Hubner 2010; Ibfelt 2015; McConeghy 2017; Miyaki 2011; Pandejpong 2012; Savolainen‐Kopra 2012; Yeung 2011). Six studies provided some description about sequence generation, but it was still unclear (Hartinger 2016; Huda 2012; Ide 2016; Little 2015; MacIntyre 2011; MacIntyre 2013). Huda 2012 mentioned random number tables, but it was unclear if this was for random selection or randomisation. Ide 2016 used computer‐generated randomisation, but the method was not stated. Hartinger 2016 used covariate‐constrained randomisation, but the method was not described. In Little 2015, participants were automatically randomly assigned by the intervention software, but the sequence generation was not described. Two studies used a secure computerised randomisation program (MacIntyre 2011; MacIntyre 2013), but the sequence generation was not described.

Three of the studies included in the 2020 review, were poorly randomised (Ban 2015; Nicholson 2014; Temime 2018). Ban 2015 included only two clusters, and the randomisation scheme was not reported. Nicholson 2014 used coin tossing, which can lead to a large imbalance. Temime 2018 used “simple randomisation” with no further description.

For the RCTs included in previous versions of the review, three were poorly reported with no description of randomisation sequence or concealment of allocation (Gwaltney 1980; Turner 2004a; Turner 2004b). The quality of the cluster‐RCTs varied, with four studies not providing a description of the randomisation procedure (Carabin 1999; Kotch 1994; Morton 2004; White 2001). We rated seven studies as at low risk of bias for sequence generation (Cowling 2008; Cowling 2009; Luby 2005; Roberts 2000; Sandora 2005; Sandora 2008; Satomura 2005), and a further six studies as at unclear risk of bias (Farr 1988a; Farr 1988b; Ladegaard 1999; Loeb 2009; Longini 1988; MacIntyre 2009).

Many of the newly included cluster‐RCTs did not report adequately on allocation concealment. Twenty‐one of these studies reported adequate allocation and were judged as at low risk of bias (Aiello 2012; Alzaher 2018; Azor‐Martinez 2016; Azor‐Martinez 2018; Biswas 2019; Canini 2010; Chard 2019; Goodall 2014; Ide 2014; Ide 2016; Little 2015; MacIntyre 2011; MacIntyre 2015; Nicholson 2014; Priest 2014; Radonovich 2019; Ram 2015; Savolainen‐Kopra 2012; Stebbins 2011; Suess 2012; Turner 2012). Aiello 2012 randomised all residence houses in each of the residence halls prior to the intervention implementation. Alzaher 2018 allocated schools prior to all schoolgirls attending selected schools being invited to participate. Azor‐Martinez 2016 allocated schools/classes prior to children's recruitment. Azor‐Martinez 2018 assigned clusters prior to recruitment. Biswas 2019 completed the allocation prior to individuals being recruited. Chard 2019 allocated schools prior to individuals being recruited. Goodall 2014 used opaque, sealed, serially numbered envelopes that were only accessed when two study personnel were present. Ide 2014 also reported using individual drawing of sealed, opaque envelopes to randomly assign participants to the study groups. MacIntyre 2011 randomised hospitals prior to inclusion of participants. In MacIntyre 2015, hospital wards were randomised prior to recruitment of individuals. Nicholson 2014 used coin tossing to assign communities to intervention or control arms. Radonovich 2019 used constrained randomisation to resolve any potential imbalance between covariates between the trial arms. Four studies reported the use of central randomisation: Canini 2010 used central randomisation by employing an interactive voice response system; Ide 2016 used central randomisation services; Little 2015 participants were automatically randomly assigned by the intervention software; and Ram 2015 described a central allocation through data collectors notifying the field research officer, who consulted the block randomisation list to make the assignment of the household compound to intervention or control. Savolainen‐Kopra 2012 randomised clusters by matching prior to the onset of the interventions. Four studies reported that allocation was assigned by personnel (investigator, physician, or statistician) unaware of the randomisation sequence (Priest 2014; Stebbins 2011; Suess 2012; Turner 2012). Twenty‐two studies reported insufficient information to permit a judgement on the adequacy of the process to minimise selection bias (Aelami 2015; Arbogast 2016; Ban 2015; Barasheed 2014; Correa 2012; DiVita 2011; Feldman 2016; Hartinger 2016; Hubner 2010; Huda 2012; Ibfelt 2015; MacIntyre 2013; McConeghy 2017; Millar 2016; Miyaki 2011; Najnin 2019; Pandejpong 2012; Simmerman 2011; Talaat 2011; Temime 2018; Yeung 2011; Zomer 2015). Two studies provided some information about allocation, but it was not enough to permit a judgement on the risk of bias (Barasheed 2014; Simmerman 2011). Barasheed 2014 randomised pilgrim tents using an independent study co‐ordinator who was not an investigator, but did not describe how this was done. Simmerman 2011 described using a study co‐ordinator to assign households to the study arm (after consent was obtained). Only one of the newly added studies was judged as at high risk of bias, where the random assignment was allocated by doctors enrolling the participants (MacIntyre 2016). Of the previously included RCTs, 14 provided no or an insufficient description of concealment of allocation (Carabin 1999; Farr 1988a; Farr 1988b; Gwaltney 1980; Kotch 1994; Ladegaard 1999; Larson 2010; MacIntyre 2009; Morton 2004; Roberts 2000; Sandora 2008; Turner 2004a; Turner 2004b; White 2001). We assessed all of the remaining studies as at low risk of bias (Canini 2010; Cowling 2008; Cowling 2009; Loeb 2009; Longini 1988; LLuby 2005; Sandora 2005;Satomura 2005). Aiello 2010 used the drawing of a uniform ticket with the name of each hall out of a container and was rated as at high risk of bias.

Blinding

Although blinding is less of a concern in cluster‐RCTs, the risk of bias is substantial when the outcomes are subjective and the outcome assessor is not blinded.

In this 2022 review, five RCTs (Almanza‐Reyes 2021; Bundgaard 2021; Fretheim 2022a; Gutiérrez‐García 2022; Helsingen 2021), and six cluster‐RCTs were all judged to have a high risk of detection bias (Abaluck 2022; Alfelali 2020; Ashraf 2020; Swarthout 2020; Teesing 2021; Young 2021).

We judged two of the newly included studies to have a low risk of detection bias as the outcome is laboratory‐confirmed (Alfelali 2020; Gutiérrez‐García 2022). One study provided insufficient information to enable judgment (Almanza‐Reyes 2021). The remaining eight of the 11 new studies have a high risk of detection bias (Abaluck 2022; Ashraf 2020; Bundgaard 2021; Fretheim 2022a; Helsingen 2021; Swarthout 2020; Teesing 2021; Young 2021). In Abaluck 2022, investigators dropped individuals for whom symptom data were missing. In addition, other outcomes were subjective and can be influenced by the unblinded mask promoters, and mask surveillance staff. Moreover, blood testing in the protocol specified baseline testing which was not done, and no further explanation was provided. In Ashraf 2020, although the data collection team was separate from the intervention team, they were not blinded, and the outcome was respiratory illness measured through caregiver‐reported symptoms. In Bundgaard 2021, case detection was based on patient‐reported symptoms on home tests. In Fretheim 2022a, the outcome was self‐reported positive COVID‐19 test result, notified to the Norwegian Surveillance System for Communicable Diseases (MSIS). However, the public policy requiring confirmatory PCR‐test had changed during the study, which may have affected reporting. In Helsingen 2021, although the outcome was a positive test for COVID‐19 based on SARS‐CoV‐2 ribonucleic acid, the samples were collected and sent by participants, and there was a difference in adherence in testing between the two groups. Swarthout 2020, Teesing 2021, and Young 2021 all had subjective outcomes and assessors were not blinded. As for the detection bias,  six of the newly included studies were considered to have a high risk of detection bias (Bundgaard 2021; Gutiérrez‐García 2022; Helsingen 2021; Swarthout 2020; Teesing 2021; Young 2021. In Bundgaard 2021, case detection was based on patient‐reported symptoms and results from home point‐of‐care (POCT) testing. The primary outcome of Gutiérrez‐García 2022 was participants' self‐reported symptoms. Case detection in Helsingen 2021 was based on a home‐test kit. Swarthout 2020, Teesing 2021, and Young 2021 had subjective outcomes.

In the 2020 review, we judged 36 studies to have a high risk of bias (Aiello 2012; Abaluck 2022; Alfelali 2020; Almanza‐Reyes 2021; Alzaher 2018; Arbogast 2016; Ashraf 2020; Azor‐Martinez 2016; Azor‐Martinez 2018; Ban 2015; Biswas 2019; Bundgaard 2021; Carabin 1999; Chard 2019; Correa 2012; Cowling 2008; Gutiérrez‐García 2022; Helsingen 2021; Ide 2014; Kotch 1994; Ladegaard 1999; Little 2015; MacIntyre 2011; MacIntyre 2015; MacIntyre 2016; McConeghy 2017; Najnin 2019; Nicholson 2014; Ram 2015; Sandora 2008; Savolainen‐Kopra 2012; Swarthout 2020; Teesing 2021; Temime 2018; Young 2021; Zomer 2015). We assessed five cluster‐RCTs as at low risk of bias. Farr 1988a and Farr 1988b were double‐blinded studies and were judged as at low risk of bias. MacIntyre 2013 and Simmerman 2011 reported laboratory‐confirmed influenza, and blinding would not have affected the result. In Miyaki 2011 the self‐reported respiratory symptoms were confirmed by a physician.

We judged four cluster‐RCTs to have a low risk of detection bias because the outcome was laboratory‐confirmed influenza (Alfelali 2020; Barasheed 2014; Suess 2012), or physician‐confirmed ILI, Pandejpong 2012. Another two cluster‐RCTs were judged to have a low risk of bias because outcome assessors were blinded (Abaluck 2022; Ashraf 2020). One RCT (Almanza‐Reyes 2021) and two cluster‐RCTs (Talaat 2011; Yeung 2011) provided insufficient data to judge the effect of non‐blinding. Talaat 2011 included outcomes that were both self‐reported ILI and laboratory‐confirmed influenza. In Yeung 2011 the detection of cases was based on records for hospitalisation related to infection (including pneumonia). Eleven cluster‐RCTs were not blinded, but we judged the primary outcome to be unaffected by non‐blinding. Seven trials reported laboratory‐confirmed influenza (Aiello 2012; Cowling 2009; Larson 2010; Loeb 2009; MacIntyre 2009; Millar 2016; Stebbins 2011). Four studies reported self‐reported outcomes (Canini 2010; Priest 2014; Roberts 2000; Sandora 2008), but outcome assessors were not aware of the intervention assignment. Five RCTs were double‐blinded and were judged as at low risk of bias (Goodall 2014; Ide 2016; Longini 1988; Luby 2005; White 2001), whilst two studies were single‐blinded where investigators, Radonovich 2019, or laboratory personnel, Turner 2012, were blinded. Four RCTs were not blinded and were judged as at high risk of bias given the subjective nature of the outcome assessed (Hubner 2010; Ibfelt 2015; Jacobs 2009; Satomura 2005). Turner 2004a and Turner 2004b were double‐blind studies, but insufficient information was provided to assess the risk of bias.

Incomplete outcome data

In this 2022 review, six of the 11 newly included studies had reasonable attrition and provided sufficient evidence about participant flow throughout the study and reasons of loss to follow‐up, and hence were assessed as having a low risk of attrition bias (Alfelali 2020; Ashraf 2020; Bundgaard 2021; Fretheim 2022a; Gutiérrez‐García 2022; Swarthout 2020). Two studies provided insufficient information to assess the attrition risk (Almanza‐Reyes 2021; Teesing 2021). The remaining three studies were judged at high risk of attrition bias. In Abaluck 2022, laboratory testing results were only available for 40% of the symptomatic participants. In Helsingen 2021, more people in the control group withdrew from the study and reasons for withdrawal were not provided. In the Young 2021 study there was high attrition at different rates between the two groups.

In the 2020 review, we assessed 26 newly included trials as having a low risk of attrition bias, with sufficient evidence from the participant flow chart, and explanation of loss to follow‐up (which was minimal) similar between groups (Aiello 2012; Alzaher 2018; Arbogast 2016; Azor‐Martinez 2018; Barasheed 2014; Canini 2010; Chard 2019; Correa 2012; Goodall 2014; Hartinger 2016; Hubner 2010; Ide 2014; Ide 2016; MacIntyre 2011; MacIntyre 2013; MacIntyre 2015; MacIntyre 2016; Miyaki 2011; Pandejpong 2012; Radonovich 2019; Ram 2015; Simmerman 2011; Suess 2012; Turner 2012; Yeung 2011; Zomer 2015). Seven studies did not report sufficient information on incomplete data (attrition bias) (Aelami 2015; DiVita 2011; Feldman 2016; Hartinger 2016; Ibfelt 2015; McConeghy 2017; Priest 2014). Twelve studies had a high risk of attrition bias (Azor‐Martinez 2016; Ban 2015; Biswas 2019; Huda 2012; Little 2015; Millar 2016; Najnin 2019; Nicholson 2014; Savolainen‐Kopra 2012; Stebbins 2011; Talaat 2011; Temime 2018). In Azor‐Martinez 2016, attrition levels were high and differed between the two groups. Ban 2015 did not report on reasons for loss to follow‐up. Biswas 2019 did not provide information on missing participants (28 children in the control schools and two children in the intervention schools). Huda 2012 did not provide a flow diagram of study participants. Little 2015 had high attrition that differed between the two groups. Attrition in Millar 2016 differed amongst the three groups. In addition, ARI cases were captured utilising clinic‐based medical records for those participants who sought hospital care only. In Najnin 2019, there was high migration movement during the study, which could have distorted the baseline characteristics even more. There was no description of how such migration and changes in the intervention group were dealt with. In Nicholson 2014, households were removed from the study if they provided no data for five consecutive weeks. Although attrition was reported in Savolainen‐Kopra 2012, and 76% of volunteers who were recruited at the beginning of the reporting period completed the study, new recruits were added during the study to replace volunteers lost in most clusters. The total number of reporting participants at the end of the trial was 626 (91.7%) compared to the beginning, meaning that 15.7% of participants were replaced during the study. In Stebbins 2011,reasons for episodes of absence in 66% of the study participants were not reported. Talaat 2011 did not provide a flow chart of clusters flow during the study period and provided no information on withdrawal. Temime 2018 was greatly biased due to underreporting of outcomes in the control groups. Furthermore, no study flow chart was provided, and there was no reporting on any exclusions.

Selective reporting

For this 2022 review update, six of the 11 newly included studies reported all specified outcomes and were judged to have a low risk of selective reporting (Ashraf 2020; Bundgaard 2021; Fretheim 2022a; Gutiérrez‐García 2022; Helsingen 2021; Young 2021). Three studies had no published protocol and were considered to have an unclear risk of selective reporting (Alfelali 2020; Almanza‐Reyes 2021; Teesing 2021). The remaining two new included studies are considered to have a high risk of bias in this domain. Abaluck 2022 did not report on prespecified seroconversion, while in Swarthout 2020, none of the outcomes reported were prespecified in the trial registry.

In the 2020 review, 22 included studies reported all specified outcomes and were judged as at low risk of reporting bias (Aiello 2012; Barasheed 2014; Canini 2010; Chard 2019; Goodall 2014; Hartinger 2016; Ibfelt 2015; Ide 2016; Little 2015; MacIntyre 2011; MacIntyre 2013; MacIntyre 2015; MacIntyre 2016; Pandejpong 2012; Priest 2014; Radonovich 2019; Savolainen‐Kopra 2012; Simmerman 2011; Suess 2012; Temime 2018; Turner 2012; Zomer 2015). For 18 studies, it is unlikely that other outcomes were measured and not reported, although no protocol was available to assess reporting bias (Aelami 2015; Alzaher 2018; Arbogast 2016; Azor‐Martinez 2016; Azor‐Martinez 2018; Ban 2015; Biswas 2019; Correa 2012; DiVita 2011; Feldman 2016; Hubner 2010; Huda 2012; Ide 2014; Miyaki 2011; Nicholson 2014; Stebbins 2011; Talaat 2011; Yeung 2011). Three studies were at high risk of reporting bias (McConeghy 2017; Millar 2016; Najnin 2019). In McConeghy 2017, URTI was mentioned in the methods (the intervention presumably would have targeted these), but only lower respiratory tract infection (LRTI) and overall infection were reported. Millar 2016 was originally conducted for another purpose; we could not find the respiratory outcomes reported in the study as part of the original study protocol. In Najnin 2019, the published study protocol did not include respiratory illness as an outcome.

Other potential sources of bias

An additional consideration for cluster‐RCTs is identification/recruitment bias, where individuals are recruited in the trial after clusters are randomised. Such bias can introduce an imbalance amongst groups.

In this 2022 review, of the six cluster‐RCTs included, we judged four to have a low risk of identification/recruitment bias (Abaluck 2022; Ashraf 2020; Swarthout 2020; Teesing 2021). In Abaluck 2022, all of people in the village were assigned to one study arm (control, cloth mask or surgical mask villages). In Ashraf 2020, participants were unaware of their intervention group assignment until after the baseline survey and randomisation. In Swarthout 2020, village clusters comprised of 12 enrolled households, while in Teesing 2021 randomisation was done per nursing home. Alfelali 2020 recruited individuals after cluster‐randomisation and is judged to have a high risk of recruitment bias, while in Young 2021, participation of students and staff contacts were made after random assignment of the school through written consent or electronic completion of a consent form.

Of the cluster‐RCTs included in our 2020 review, we judged 13 to have a low risk of identification/recruitment bias (Arbogast 2016; Biswas 2019; Canini 2010; Cowling 2008; Longini 1988; Luby 2005; MacIntyre 2015; MacIntyre 2016; Roberts 2000; Sandora 2005; Suess 2012; Temime 2018; White 2001). In Arbogast 2016, all identified individuals (office workers) were included in the assigned cluster. Schools were identified and then randomised to the clusters; students were then randomly selected from each classroom and school. Nine studies described the identification of participants, consenting/enrolling, and then randomising to the clusters (Canini 2010; Cowling 2008; Longini 1988; Luby 2005; MacIntyre 2015; MacIntyre 2016; Roberts 2000; Sandora 2005; White 2001). Suess 2012 identified and consented patients, then recruitment was performed by physicians unaware of cluster assignment. In Temime 2018, directors of the included nursing homes agreed to participate in the study before randomisation, and written consent was not required from the residents.

Amongst the newly included studies, we judged four cluster‐RCTs as at low risk of identification/recruitment bias (Abaluck 2022; Swarthout 2020; Teesing 2021; Young 2021). In Abaluck 2022, the village was the unit of randomisation and all households received one arm of the study (control, surgical mask or cloth mask). In Swarthout 2020, village clusters were each randomised by blocks (group of nine adjacent clusters) into eight groups. In Teesing 2021 nursing homes were computer randomised after baseline hand hygiene measurements to either the intervention arm or the control arm. In Young 2021, schools were randomly assigned (1:1) to either a policy of offering contacts daily testing over seven days to allow continued school attendance (intervention group) or to follow the usual policy of isolation of contacts for 10 days (control group). In two studies there were insufficient details to permit a judgement of the risk of bias (Alfelali 2020; Ashraf 2020).

In the 2020 review, we judged 11 cluster‐RCTs as at high risk of identification/recruitment bias (Aiello 2010; Aiello 2012; Azor‐Martinez 2018; Chard 2019; Correa 2012; Cowling 2009; Larson 2010; McConeghy 2017; Nicholson 2014; Priest 2014; Savolainen‐Kopra 2012). In Aiello 2010 and Aiello 2012, recruitment continued for two weeks after the start of the study, which could have introduced bias. Six trials identified and recruited participants after cluster randomisation (Azor‐Martinez 2018; Chard 2019; Cowling 2009; Larson 2010; McConeghy 2017; Nicholson 2014). Three trials recruited new participants after the start of the study to replace those lost to follow‐up (Correa 2012; Priest 2014; Savolainen‐Kopra 2012). We judged five cluster‐RCTs to have probable identification/recruitment bias (Alzaher 2018; Barasheed 2014; MacIntyre 2011; Najnin 2019; Radonovich 2019), whereas in 19 studies there were insufficient details to permit a judgement of risk of bias (Carabin 1999; DiVita 2011; Feldman 2016; Hartinger 2016; Huda 2012; Ibfelt 2015; Kotch 1994; Ladegaard 1999; MacIntyre 2009; MacIntyre 2013; Millar 2016; Miyaki 2011; Pandejpong 2012; Radonovich 2019; Sandora 2008; Stebbins 2011; Talaat 2011; Yeung 2011; Zomer 2015).

Two of the newly included cluster‐RCTs reported intracluster correlation coefficient (ICC) to adjust sample size, taking into consideration clustering effects, and described adjusting outcomes for clustering effect using different statistical methods, or provided justification for not performing adjusted analysis for clustering (Alfelali 2020; Swarthout 2020). For four studies there were insufficient details to permit a judgement of risk of bias (Abaluck 2022; Ashraf 2020; Teesing 2021; Young 2021) since they provided insufficient details on ICC and/or did not perform adjusted analysis or justified the absence of it.

Twenty‐six cluster‐RCTs identified in the 2020 review reported intracluster correlation coefficient (ICC) to adjust sample size, taking into consideration clustering effects, and described adjusting outcomes for clustering effect using different statistical methods, or provided justification for not performing adjusted analysis for clustering (Aiello 2010; Aiello 2012; Arbogast 2016; Canini 2010; Carabin 1999; Correa 2012; Cowling 2008; Cowling 2009; Hartinger 2016; Huda 2012; Little 2015; Luby 2005; MacIntyre 2009; MacIntyre 2011; MacIntyre 2013; MacIntyre 2015; MacIntyre 2016; McConeghy 2017; Priest 2014; Radonovich 2019; Ram 2015; Roberts 2000; Stebbins 2011; Suess 2012; Talaat 2011; Temime 2018). Five cluster‐RCTs did not report the ICC but described adjusting outcomes for clustering effect using different statistical methods, or explained why adjusted analysis for clustering was not performed (Biswas 2019; Chard 2019; McConeghy 2017; Simmerman 2011; Zomer 2015). Thirteen cluster‐RCTs provided insufficient details on ICC and/or did not perform adjusted analysis or justified the absence of it (Alzaher 2018; Azor‐Martinez 2016; Azor‐Martinez 2018; Barasheed 2014; Feldman 2016; Larson 2010; Millar 2016; Miyaki 2011; Najnin 2019; Nicholson 2014; Pandejpong 2012; Savolainen‐Kopra 2012; Yeung 2011). Two cluster‐RCTs reported the ICC but did not perform adjusted analysis or justified the absence of it (Sandora 2005; Sandora 2008).

Effects of interventions

See: Table 1; Table 2; Table 3

Comparison 1: Medical/surgical masks compared to no masks

We included 12 trials (10 of which were cluster‐RCTs) comparing medical/surgical masks versus no masks (Abaluck 2022; Alfelali 2020; Aiello 2012; Barasheed 2014; Bundgaard 2021; Canini 2010; Cowling 2008; Jacobs 2009; MacIntyre 2009; MacIntyre 2015; MacIntyre 2016; Suess 2012). Two trials were conducted with healthcare workers (HCWs) (Jacobs 2009; MacIntyre 2015), whilst the other 10 studies included people living in the community. In the acute care hospital setting, as opposed to the community setting, variable mask use occurred, according to usual practices in the settings where the studies were undertaken, varying from just under 16% most of the time to 23.6% wearing for > 70% of all working hours (Jacobs 2009; MacIntyre 2015). We therefore excluded the two studies in the acute care hospital setting from the meta‐analysis, and report results from these studies narratively. Ten trials were conducted in non‐pandemic settings, and two were conducted during the SARS‐CoV‐2 pandemic (Abaluck 2022; Bundgaard 2021).

Primary outcomes

1. Numbers of cases of viral respiratory illness

Influenza/COVID‐like illness

Pooling of nine trials conducted in the community found an estimate of effect for the outcomes of influenza/COVID‐like illness cases (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.84 to 1.09; 9 trials; 276,917 participants; moderate‐certainty evidence; Analysis 1.1) suggesting that wearing a medical/surgical mask will probably make little or no difference for this outcome. Two studies in healthcare workers provided inconclusive results with very wide confidence intervals: RR 0.88, 95% CI 0.02 to 32; and RR 0.26, 95% CI 0.03 to 2.51, respectively (Jacobs 2009; MacIntyre 2015).

Laboratory‐confirmed influenza/SARS‐CoV‐2 cases

Similarly, the estimate of effect for laboratory‐confirmed influenza/SARS‐CoV‐2 cases (RR 1.01, 95% CI 0.72 to 1.42; 6 trials, 13,919 participants; moderate‐certainty evidence; Analysis 1.1) suggests that wearing a medical/surgical mask probably makes little or no difference compared to not wearing a mask for this outcome.

Laboratory‐confirmed other respiratory viruses

One community study reported on laboratory‐confirmed other respiratory viruses, showing RR 0.58, 95% CI 0.25 to 1.31; Analysis 1.1, and another study in healthcare workers reported RR 0.79, 95% CI 0.42 to 1.52 (MacIntyre 2015).

Assessing both source control and personal protection

The design of most trials assessed whether masks protected the wearer. Six trials were cluster‐RCTs, with all participants in the intervention clusters required to wear masks, thus assessing both source control and personal protection. In two trials the clusters were households with a member with new influenza; neither of these studies found any protective effect (RR 1.03 in 105 households (Canini 2010); RR 1.21 in 145 households (MacIntyre 2009)). In two trials the clusters were college dormitories during the influenza season; neither study found any reduction (RR 1.10 in 37 dormitories (Aiello 2012); RR 0.90 in three dormitories (Aiello 2010)).

Studies conducted during the SARS‐CoV‐2 pandemic

Two studies were conducted during the SARS‐CoV‐2 pandemic (Abaluck 2022; Bundgaard 2021), with the former being a very large cluster‐RCT of villages in Bangledesh and the latter a large RCT conducted in Denmark.

Exclusion of study due to insufficient number of clusters

We excluded Aiello 2010 from the meta‐analysis since we did not consider 'randomisation' of three clusters to three arms to be a proper randomised trial.

2. Adverse events related to the intervention

Canini 2010 reported that 38 (75%) of participants in the intervention arm experienced discomfort with the mask use due to warmth (45%), respiratory difficulties (33%), and humidity (33%). Children reported feeling pain more frequently (3/12) than other participants wearing adult face masks (1/39; P = 0.04). In MacIntyre 2015, adverse events associated with face mask use were reported in 40.4% (227/562) of HCWs in the medical‐mask arm. General discomfort (35.1%; 397/1130) and breathing problems (18.3%; 207/1130) were the most frequently reported adverse events. Suess 2012 reported that the majority of participants (107/172; 62%) did not report any problems with mask‐wearing. More adults reported no problems (71%) compared to children (36/72; 50%; P = 0.005). The main issues when wearing a face mask for adults as well as for children were "heat/humidity" (18/34; 53% of children; 10/29; 35% of adults; P = 0.1), followed by "pain" and "shortness of breath". Alfelali 2020 reported the most common side effects of wearing a mask in Hajj pilgrims were difficulty in breathing (26%) and discomfort (22%). Although no details were provided, Bundgaard 2021 mentioned that 14% of participants had adverse reactions. Cowling 2008 and Abaluck 2022 mentioned that no adverse events were reported. The other trials did not report measuring adverse outcomes.

Secondary outcomes

1. Deaths

Not reported.

2. Severity of viral respiratory illness as reported in the studies

Jacobs 2009 reported that participants in the mask group were significantly more likely to experience more days with headache and feeling bad. They found no significant differences between the two groups for symptom severity scores. None of the other trials reported this outcome.

3. Absenteeism

Not reported.

4. Hospital admissions

Not reported.

5. Complications related to the illness (e.g. pneumonia)

Not reported.

Comparison 2: N95/P2 respirators compared to medical/surgical masks

We included five trials comparing medical/surgical masks with N95/P2 respirators (Loeb 2009; MacIntyre 2009; MacIntyre 2011; MacIntyre 2013; Radonovich 2019). All of these trials except MacIntyre 2009 included HCWs. MacIntyre 2009 included carers and household members of children with a respiratory illness recruited from a paediatric outpatient department and a paediatric primary care practice in Sydney, Australia. None of the trials were conducted during the SARS‐CoV‐2 pandemic.

Primary outcomes

1. Numbers of cases of viral respiratory illness

Clinical respiratory illness

Pooling of three trials found an estimate of effect suggesting considerable uncertainty as to whether an N95/P2 respirator provides any benefit compared to medical/surgical masks for the outcome of clinical respiratory illness (RR 0.70, 95% CI 0.45 to 1.10; 7799 participants, very low‐certainty evidence; Analysis 2.1) (MacIntyre 2011; MacIntyre 2013 (two arms); Radonovich 2019).

Influenza‐like‐illness

Based on five trials conducted in four healthcare settings and one household, the estimates of effect for the outcome of ILI (RR 0.82, 95% CI 0.66 to 1.03; 8407 participants, low‐certainty evidence; Analysis 2.1) suggest that N95/P2 respirators may make little or no difference for this outcome (Loeb 2009; MacIntyre 2009; MacIntyre 2011; MacIntyre 2013; Radonovich 2019).

Laboratory‐confirmed influenza

The estimate of the effect for the outcome of laboratory‐confirmed influenza infection (RR 1.10, 95% CI 0.90 to 1.34; 8407 participants, moderate‐certainty evidence; Analysis 2.1) suggests that the use of a N95/P2 respirator compared to a medical/surgical mask probably makes little or no difference for this more precise and objective outcome.

The outcomes clinical respiratory illness and ILI were reported separately. Considering how these outcomes were defined, it is highly likely that there was considerable overlap between the two, therefore these outcomes were not combined into a single clinical outcome (Analysis 2.1). The laboratory‐confirmed viral respiratory infection outcome included influenza primarily but multiple other common viral respiratory pathogens were also included in several studies. The laboratory‐confirmed viral infection outcome was considered more precise and objective in comparison to the clinical outcomes, which were more subjective and considered to be less precise. The findings did not change when we restricted the evidence to HCWs (Analysis 2.2).

2. Adverse events related to the intervention

Harms were poorly reported, but generally discomfort wearing medical/surgical masks and N95/P32 respirators was mentioned in several studies. Radonovich 2019 mentioned that participants wearing the N95 respirator reported skin irritation and worsening of acne. MacIntyre 2011 reported that adverse events were more common with N95 respirators; in particular, discomfort was reported in 41.9% of N95 wearers versus 9.8% of medical‐mask wearers (P < 0.01); headaches were more common with N95 (13.4% versus 3.9%; P < 0.01); difficulty breathing was reported more often in the N95 group (19.4% versus 12.5%; P = 0.01); and N95 caused more problems with pressure on the nose (52.2% versus 11.0%; P < 0.01). In MacIntyre 2013, fewer participants using the N95 respirator reported problems (38% (195/512) versus 48% (274/571) of participants in the medical‐mask arm; P = 0.001). Loeb 2009 mentioned that no adverse events were reported.

The one trial conducted in the community mentioned that more than 50% of participants reported concerns with both types of masks, mainly that wearing them was uncomfortable, but there were no significant differences between the P2 (N95) and surgical‐mask groups (MacIntyre 2009).

Secondary outcomes

1. Deaths

Not reported.

2. Severity of viral respiratory illness as reported in the studies

Not reported.

3. Absenteeism

Loeb 2009 reported that 42 participants (19.8%) in the surgical‐mask group reported an episode of work‐related absenteeism compared with 39 (18.6%) of participants in the N95 respiratory group (absolute risk difference −1.24%, 95% CI −8.75% to 6.27%; P = 0.75).

4. Hospital admissions

Not reported.

5. Complications related to the illness (e.g. pneumonia)

Loeb 2009 reported that there were no episodes of LRTIs.

Comparison 3: Hand hygiene compared to control

Nineteen trials compared hand hygiene interventions with control and provided sufficient data to include in meta‐analyses (Ashraf 2020; Azor‐Martinez 2018; Biswas 2019; Correa 2012; Cowling 2008; Cowling 2009; Hubner 2010; Larson 2010; Little 2015; Millar 2016; Nicholson 2014; Ram 2015; Roberts 2000; Sandora 2005; Simmerman 2011; Stebbins 2011; Swarthout 2020; Teesing 2021; Zomer 2015). The populations of these studies included adults, children, and families, in settings such as schools, childcare centres, homes, and offices. None of the studies was conducted during a pandemic, although a few studies were conducted during peak influenza seasons. A further 16 trials comparing hand hygiene to a control had other outcomes or insufficient information to include in meta‐analyses (Alzaher 2018; Arbogast 2016; Azor‐Martinez 2016; DiVita 2011; Feldman 2016; Gwaltney 1980; Ladegaard 1999; Luby 2005; Morton 2004; Priest 2014; Savolainen‐Kopra 2012; Talaat 2011; Temime 2018; Turner 2012; White 2001; Yeung 2011). The results of these trials were consistent with the findings of our meta‐analyses. The results for all outcomes from the 19 trials that were meta‐analysed and the 16 trials that were not meta‐analysed are shown in Table 5.

Primary outcomes

1. Numbers of cases of viral respiratory illness

Acute respiratory infection (ARI)

Pooling of nine trials for the broad outcome of ARI showed a 14% relative reduction in the numbers of participants with ARI (RR 0.86, 95% CI 0.81 to 0.90; 52,105 participants, moderate‐certainty evidence; Analysis 3.1.1) in the hand hygiene group (Analysis 3.1), suggesting a probable benefit (Ashraf 2020; Azor‐Martinez 2018; Correa 2012; Larson 2010; Little 2015; Millar 2016; Nicholson 2014; Sandora 2005; Swarthout 2020).

Influenza‐like‐illness (ILI) and laboratory‐confirmed influenza

When considering the more strictly defined outcomes of ILI (Biswas 2019; Cowling 2008; Cowling 2009; Hubner 2010; Larson 2010; Little 2015; Ram 2015; Roberts 2000; Simmerman 2011; Teesing 2021; Zomer 2015), and laboratory‐confirmed influenza (Biswas 2019; Cowling 2008; Cowling 2009; Hubner 2010; Larson 2010; Ram 2015; Simmerman 2011; Stebbins 2011) the estimates of the effect were heterogeneous, suggesting that hand hygiene may make little or no difference (RR 0.94, 95% CI 0.81 to 1.09 for ILI; 34,503 participants, low‐certainty evidence; Analysis 3.1.2); (RR 0.91, 95% CI 0.63 to 1.30 for laboratory‐confirmed influenza; 8332 participants; low‐certainty evidence; Analysis 3.1.3).

Composite outcome ‘ARI or ILI or influenza'

All 19 trials could be pooled for analysis of the composite outcome ‘ARI or ILI or influenza’, with each study only contributing once with the most comprehensive outcome (in terms of number of events) reported showing an 11% relative reduction in participants with a respiratory illness, suggesting that hand hygiene may offer a benefit (RR 0.89, 95% CI 0.83 to 0.94; low‐certainty evidence; Analysis 3.2), but with high heterogeneity. A funnel plot of the 19 trial results did not appear to suggest any small study effects for this outcome (Figure 4).

4 (Figure not reproduced here; see the original article.)

Sensitivity analysis

In a sensitivity analysis we used only the most precise and unequivocal (with laboratory confirmed considered the most precise and an undefined ARI considered the least precise) outcome reported in each of 12 studies identified by JMC, an infectious disease physician, and found an estimate of effect in favour of hand hygiene, but with wider CIs (RR 0.88, 95% CI 0.77 to 1.02; Analysis 3.3).

Subgroup analysis by age group

We considered that studies in children might have a different effect than studies in adults, so we conducted subgroup analysis by age group. We found no evidence of a difference in treatment effect by age group (P = 0.18; Analysis 3.4).

2. Adverse events related to the intervention

Correa 2012 reported that no adverse events were observed; in the study by Priest 2014, skin reaction was recorded for 10.4% of participants in the hand sanitiser group versus 10.3% in the control group (RR 1.01, 95% CI 0.78 to 1.30).

Secondary outcomes

1. Deaths

Not reported.

2. Severity of viral respiratory illness as reported in the studies

Not reported.

3. Absenteeism

Three trials measured absenteeism from school or work and demonstrated a 36% relative reduction in the numbers of participants with absence in the hand hygiene group (RR 0.64, 95% CI 0.58 to 0.71; Analysis 3.5) (Azor‐Martinez 2016; Hubner 2010; Nicholson 2014).

4. Hospital admissions

Not reported.

5. Complications related to the illness (e.g. pneumonia)

Not reported.

Comparison 4: Hand hygiene + medical/surgical masks compared to control

Primary outcomes

1. Numbers of cases of viral respiratory illness (including ARIs, ILI, and laboratory‐confirmed influenza)

Six trials (Aelami 2015; Aiello 2012; Cowling 2009; Larson 2010; Simmerman 2011; Suess 2012) were able to be pooled to compare the use of the combination of hand hygiene and medical/surgical masks with control. Four of these trials were in households, two in university student residences, and one at the annual Hajj pilgrimage. For the outcomes ILI and laboratory‐confirmed influenza, pooling demonstrated an estimate of effect suggesting little or no difference between the hand hygiene and medical/surgical mask combination and control. The number of trials and events was lower than for comparisons of hand hygiene alone, or medical/surgical masks alone, and the confidence interval was wide. For ILI, the RR for intervention compared to control was 1.03 (95% CI 0.77 to 1.37; 4504 participants; Analysis 4.1.1), and for influenza it was 0.97 (95% CI 0.69 to 1.36; 3121 participants; Analysis 4.1.2). Full results of these trials are shown in Table 6

2. Adverse events related to the intervention

Adverse events related to mask wearing in the study by Suess 2012 are reported under Comparison 1 (medical/surgical masks). There was no mention of adverse events related to hand hygiene.

Secondary outcomes

1. Deaths

Not reported.

2. Severity of viral respiratory illness as reported in the studies

Not reported.

3. Absenteeism

Not reported.

4. Hospital admissions

Not reported.

5. Complications related to the illness, e.g. pneumonia

Not reported.

Comparison 5: Hand hygiene + medical/surgical masks compared to hand hygiene

Primary outcomes

1. Numbers of cases of viral respiratory illness (including ARIs, ILI and laboratory‐confirmed influenza)

Three trials studied the addition of medical/surgical masks to hand hygiene (Cowling 2009; Larson 2010; Simmerman 2011). All three trials had three arms, and are also included in the comparison of hand hygiene plus medical/surgical mask versus control (Comparison 4). All three studies showed no difference between hand hygiene plus medical/surgical mask groups and hand hygiene alone, for all outcomes. The estimates of effect suggested little or no difference when adding masks to hand hygiene compared to hand hygiene alone: for the outcome ILI (RR 1.03, 95% CI 0.69 to 1.53; 3 trials) and the outcome laboratory‐confirmed influenza (RR 0.99, 95% CI 0.69 to 1.44), the estimates of effect were not different and the CIs were relatively wide, suggesting little or no difference (Analysis 5.1). However, the CIs around the estimates were wide and do not rule out an important benefit.

2. Adverse events related to the intervention

Not reported.

Secondary outcomes

1. Deaths

Not reported.

2. Severity of viral respiratory illness as reported in the studies

Not reported.

3. Absenteeism

Not reported.

4. Hospital admissions

Not reported.

5. Complications related to the illness (e.g. pneumonia)

Not reported.

Comparison 6: Medical/surgical masks compared to other (non‐N95) masks

One trial compared medical/surgical masks with cloth masks in hospital healthcare workers (MacIntyre 2015), and another trial compared catechin‐treated masks versus control masks in healthcare workers and staff of hospitals, rehabilitation centres, and nursing homes in Japan (Ide 2016).

Primary outcomes

1. Numbers of cases of viral respiratory illness (including ARIs, ILI, and laboratory‐confirmed influenza)

MacIntyre 2015 found that the rate of ILI was higher in the cloth mask arm compared to the medical/surgical masks arm (RR 13.25, 95% CI 1.74 to 100.97).

Ide 2016 did not find a benefit from the catechin‐treated masks over untreated masks on influenza infection rates (adjusted odds ratio (OR) 2.35, 95% CI 0.40 to 13.72; P = 0.34).

2. Adverse events related to the intervention

In MacIntyre 2015 adverse events associated with face mask use were reported in 40.4% (227/562) of HCWs in the medical/surgical mask arm and 42.6% (242/568) in the cloth mask arm (P = 0.45). The most frequently reported adverse events were general discomfort (35.1%; 397/1130) and breathing problems (18.3%; 207/1130). Laboratory tests showed the penetration of particles through the cloth masks to be very high (97%) compared with medical/surgical masks (44%). Ide 2016 reported that there were no serious adverse events associated with the intervention.

Secondary outcomes

1. Deaths

Not reported.

2. Severity of viral respiratory illness as reported in the studies

Not reported.

3. Absenteeism

Not reported.

4. Hospital admissions

Not reported.

5. Complications related to the illness (e.g. pneumonia)

Not reported.

Comparison 7: Soap + water compared to sanitiser, and comparisons of different types of sanitiser

Two trials compared soap and water with sanitiser (Azor‐Martinez 2018; Savolainen‐Kopra 2012). Another trial compared different types of hand sanitiser in a virus challenge study (Turner 2004a; Turner 2004b), and one trial studied the frequency of use of hand sanitiser (Pandejpong 2012). The full results of these four trials are shown in Table 7.

Primary outcomes

1. Numbers of cases of viral respiratory illness (including ARIs, ILI, and laboratory‐confirmed influenza)

In the trial by Azor‐Martinez 2018, ARI incidence was significantly higher in the soap‐and‐water group compared with the hand sanitiser group (rate ratio 1.21, 95% CI 1.06 to 1.39). In contrast, there was no significant difference between interventions in Savolainen‐Kopra 2012. In the rhinovirus challenge study (Turner 2004a; Turner 2004b), all hand sanitisers tested led to a significant lowering of infection rates, but no differences between sanitisers were observed. The study sample size was small.

2. Adverse events related to the intervention

Two trials stated that no adverse events were observed (Pandejpong 2012; Savolainen‐Kopra 2012).

Secondary outcomes

1. Deaths

Not reported.

2. Severity of viral respiratory illness as reported in the studies

Not reported.

3. Absenteeism

The authors of Azor‐Martinez 2018 also observed a significant benefit for hand sanitiser in reduction in days absent, whereas there was no difference between intervention groups in the Savolainen‐Kopra 2012 trial. The study on frequency of use of sanitiser found that use of sanitiser every hour significantly reduced days absent compared with use every two hours or with use only before the lunch break (Pandejpong 2012).

4. Hospital admissions

Not reported.

5. Complications related to the illness (e.g. pneumonia)

Not reported.

Comparison 8: Surface/object disinfection (with or without hand hygiene) compared to control

Primary outcomes

1. Numbers of cases of viral respiratory illness (including ARIs, ILI, and laboratory‐confirmed influenza)

Six trials contributed data to this comparison (Ban 2015; Carabin 1999; Ibfelt 2015; Kotch 1994; McConeghy 2017; Sandora 2008). Full results of these trials are shown in Table 8. Five of the six trials combined disinfection with other interventions such as hand hygiene education, provision of hand hygiene products, and audits. Ban 2015 utilised a combination of provision of hand hygiene products, and cleaning and disinfection of surfaces, and demonstrated a significant reduction in ARI in the intervention group (OR 0.47, 95% CI 0.48 to 0.65). A similar result was seen in Carabin 1999, with a significant reduction in episodes of ARI. Two studies tested multi component interventions and observed no significant difference in ARI outcomes (Kotch 1994; McConeghy 2017).

One trial compared disinfection alone to usual care (Ibfelt 2015). This study demonstrated a significant reduction in some viruses detected on surfaces in the childcare centres (adenovirus, rhinovirus, respiratory syncytial virus (RSV), and metapneumovirus), but not in other viruses, including coronavirus.

2. Adverse events related to the intervention

Not reported.

Secondary outcomes

1. Deaths

Not reported.

2. Severity of viral respiratory illness as reported in the studies

Not reported.

3. Absenteeism

Only one study measured this outcome (Sandora 2008), observing no significant difference between groups for the outcome of absence due to respiratory illness (rate ratio for intervention to control 1.10, 95% CI 0.97 to 1.24).

4. Hospital admissions

Not reported.

5. Complications related to the illness (e.g. pneumonia)

Not reported.

Comparison 9: Complex interventions compared to control

Complex interventions are either multifaceted environmental programmes (such as those in low‐income countries) or combined interventions including hygiene measures and gloves, gowns, and masks.

Four trials studied complex hygiene and sanitation interventions in low‐income country settings (Chard 2019; Hartinger 2016; Huda 2012; Najnin 2019). Full results from these studies are given in Table 9.

Primary outcomes

1. Numbers of cases of viral respiratory illness (including ARIs, ILI, and laboratory‐confirmed influenza)

All four trials of complex interventions observed no significant differences between groups in rates of viral respiratory illness.

2. Adverse events related to the intervention

Not reported.

Secondary outcomes

1. Deaths

Not reported.

2. Severity of viral respiratory illness as reported in the studies

Not reported.

3. Absenteeism

Not reported.

4. Hospital admissions

Not reported.

5. Complications related to the illness (e.g. pneumonia)

Not reported.

Comparison 10: Physical distancing/quarantine

We found three RCTs that assessed physical distancing/quarantine interventions. A quasi‐cluster‐RCT assessed the effectiveness of quarantining workers of one of two sibling companies in Japan whose family members developed an ILI during the 2009 to 2010 H1N1 influenza pandemic (Miyaki 2011). Workers in the intervention group were asked to stay home on full pay until five days after the household member(s) showed resolution of symptoms or two days after alleviation of fever. A second RCT conducted during the SARS‐CoV‐2 pandemic investigated whether attending fitness centres with physical distancing  was non‐inferior compared to no access in terms of COVID‐19 transmission (Helsingen 2021). The third study was a cluster‐RCT conducted during the SARS‐CoV‐2 pandemic that compared voluntary daily lateral flow device testing for seven days with negative contacts remaining at school to self‐isolation of school‐based COVID‐19 contacts for 10 days in a non‐inferiority design (Young 2021).

Primary outcomes

1. Numbers of cases of viral respiratory illness (including laboratory‐confirmed influenza and SARS‐CoV‐2)

Miyaki 2011 reported adherence with the intervention was 100%. In the intervention group 2.75% of workers contracted influenza, compared with 3.18% in the control group (Cox hazard ratio 0.799, 95% CI 0.66 to 0.97; P = 0.02), indicating that the rate of infection was reduced by 20% in the intervention group. However, the risk of a worker being infected was 2.17‐fold higher in the intervention group where workers stayed at home with their infected family members. The authors concluded that quarantining workers who have infected household members could be a useful additional measure to control the spread of respiratory viruses in an epidemic setting.

Helsingen 2021 reported 3016 participants were tested for SARS‐CoV‐2 resulting in one positive case in the fitness centre access arm versus zero in the no access arm at 14 days (risk difference (RD) 0.053%, 95% CI − 0.050 to 0.156%;  P = 0.32). In addition, 11 in the fitness centre access arm versus 27 in the no access arm tested positive for SARS‐CoV‐2 antibodies at one month (RD − 0.87%, 95% CI − 1.52% to − 0.23%; P = 0.001). The authors concluded that access to fitness centres with physical distancing and low population prevalence of SARS‐CoV‐2 infection did not increase risk of SARS‐CoV‐2 infection.

Results from Young 2021 suggested no difference between the two treatment arms for SARS‐CoV‐2 infection (RR 0.96, 95% CI 0.75 to 1.22) leading the study authors to conclude non‐inferiority of daily contact testing of school‐based contacts (intervention) compared to self‐isolation (control).

2. Adverse events related to the intervention

Not reported.

Secondary outcomes

1. Deaths

Not reported.

2. Severity of viral respiratory illness as reported in the studies

Not reported.

3. Absenteeism

Young 2021 reported COVID‐19 related absences from school were similar in the two treatment groups (RR 0.80, 95% CI  0.54 to 1.19).

4. Hospital admissions

Helsingen 2021 reported no hospital admissions in either treatment arm.

5. Complications related to the illness (e.g. pneumonia)

Not reported.

Comparison 11: Eye protection compared to control

Primary outcomes

1. Numbers of cases of viral respiratory illness (including laboratory‐confirmed influenza and SARS‐CoV‐2)

We only identified one trial of eye protection which was a preprint only (Fretheim 2022a). This was a pragmatic RCT conducted in Norway from 2 February to 24 April 2022, where 3717 participants were randomised to an intervention group asked to wear glasses (e.g. sunglasses) for two weeks when close to others in public spaces. COVID‐19 cases in the national registry were 3.7% in the intervention group (68/1852) and 3.5% (65/1865) in the control group (RR 1.10, 95% CI 0.75 to 1.50). Positive COVID‐19 tests based on self‐reporting were 9.6% and 11.5% (RR 0.83, 95% CI 0.69 to 1.00). Given the high risk of bias and wide CIs, no policy conclusions can be drawn, but replication studies are clearly warranted. Almost a third of the participants reported respiratory infections. However, a lower proportion of those (215 participants) were in the intervention group compared to the control group (RR 0.90; 95% CI 0.82 to 0.99).

2. Adverse events related to the intervention

A total of 76 participants reported a negative experience from participating in the trial (53 in the intervention group and 23 in the control group). The most common complaint related to the combination of wearing glasses and face masks, and 21 participants in the intervention group cited fogging as an issue. Some participants reported feeling tired or uncomfortable wearing glasses, and a few participants complained of reduced vision when wearing sunglasses or reading glasses. In the control group some participants reported headaches from not being able to wear glasses, and one participant in the intervention group reported a fall due to reduced vision.

Secondary outcomes

1. Deaths

Not reported.

2. Severity of viral respiratory illness as reported in the studies

Not reported.

3. Absenteeism

Not reported.

4. Hospital admissions

Not reported.

5. Complications related to the illness, e.g. pneumonia

Not reported.

Comparison 12: Gargling/nose rinsing compared to control

Five trials investigated the effect of gargling/nose rinsing. Satomura 2005 compared throat gargling with povidone‐iodine versus tap water in healthy adults. Ide 2014 compared gargling with green tea versus tap water in high school students, and Goodall 2014 compared gargling with tap water with no gargling in university students. Two additional trials were conducted during the SARS‐CoV‐2 pandemic: Almanza‐Reyes 2021 compared silver mouth wash/nose rinse versus conventional mouthwashes and nose rinse in health workers; and Gutiérrez‐García 2022 compared neutral electrolysed water mouth and nose rinses versus no rinses in health workers.

Primary outcomes

1. Numbers of cases of viral respiratory illness (including ARIs, ILI, and laboratory‐confirmed influenza and SARS‐CoV‐2)

Satomura 2005 reported that gargling with tap water reduced the incidence of URTIs compared to the control group (usual care) (hazard ratio (HR) 0.60, 95% CI 0.39 to 0.95). Gargling with povidone‐iodine did not reduce the incidence of URTIs compared to the control group (HR 0.88, 95% CI 0.58 to 1.34).

Goodall 2014 found no difference in laboratory‐confirmed URTIs between the gargling (tap water) and no‐gargling groups (RR for gargling versus no gargling 0.82, 95% CI 0.53 to 1.26; P = 0.36).

In a meta‐analysis of gargling versus control based on two trials the pooled estimate of effect suggested little or no difference for the outcome of clinical URTI due to gargling (RR 0.91, 95% CI 0.63 to 1.31; 830 participants; Analysis 6.1) (Goodall 2014; Satomura 2005).

There was no difference in the incidence of laboratory‐confirmed influenza between high school students gargling with green tea compared with those using tap water (adjusted OR 0.69, 95% CI 0.37 to 1.28; P = 0.24) (Ide 2014). There was also no difference in the incidence of clinically defined influenza (adjusted OR 0.75, 95% CI 0.50 to 1.13; P = 0.17). However, the authors reported that adherence to the interventions amongst students was low.

Almanza‐Reyes 2021 reported the incidence of SARS‐CoV‐2 infection was statistically significantly lower in the silver mouth wash/nose rinse group (two out of 114, 1.8%) compared to the conventional mouthwash group (33 out of 117, 28.2%), and Gutiérrez‐García 2022 reported the incidence of COVID‐19‐positive cases in the nasal and oral rinses group was 1% compared to 13% in the control group (RR 0.09, 95% CI of 0.01 to 0.72). A meta‐analysis of these two studies showed a 93% reduction in risk of SARS‐CoV‐2 (RR 0.07, 95% CI 0.02 to 0.23; 394 participants; Analysis 6.2).

2. Adverse events related to the intervention

Satomura 2005 reported no adverse events during the 60‐day intervention period. Ide 2014 also did not observe any adverse events during the study. Goodall 2014 did not report on adverse effects. There were no adverse reactions in the study by Almanza‐Reyes 2021 or side effects in the study by Gutiérrez‐García 2022.

Secondary outcomes

1. Deaths

Not reported.

2. Severity of viral respiratory illness as reported in the studies

Satomura 2005 reported that the mean peak score in bronchial symptoms was lower in the water gargling group (0.97) than in the povidone‐iodine gargling group (1.41) and the control group (1.40), P = 0.055. Other symptoms were not significantly different between groups. Goodall 2014 reported that symptom severity was greater in the gargling group for clinical and laboratory‐confirmed URTI, but this was not statistically significant (225.3 versus 191.8, and 210.5 versus 191.8, respectively). Ide 2014 did not report symptom or illness severity.

3. Absenteeism

Not reported.

4. Hospital admissions

Not reported.

5. Complications related to the illness (e.g. pneumonia)

Not reported.

Comparison 13: Virucidal tissues compared to control

Two reports (three trials) conducted in the USA studied the effect of virucidal tissues (Farr 1988a; Farr 1988b; Longini 1988). Full results from these studies are given in Table 10.

Primary outcomes

1. Numbers of cases of viral respiratory illness (including ARIs, ILI, and laboratory‐confirmed influenza)

The three trials of virucidal tissues reported no differences in infection rates between tissues and placebo, and between tissues and no tissues (Farr 1988a; Farr 1988b; Longini 1988).

2. Adverse events related to the intervention

Farr 1988b reported cough in 4% of participants using virucidal tissues versus 57% in the placebo group, but 24% reported nasal burning in the virucidal tissue group versus 8% in the placebo group. Longini 1988 did not report on adverse effects.

Secondary outcomes

1. Deaths

Not reported.

2. Severity of viral respiratory illness as reported in the studies

Not reported.

3. Absenteeism

Not reported.

4. Hospital admissions

Not reported.

5. Complications related to the illness (e.g. pneumonia)

Not reported.

Discussion

Summary of main results

See Table 11.

1. Medical/surgical masks compared to no masks

The pooled estimates of effect from randomised controlled trials (RCTs) and cluster‐RCTs for wearing medical/surgical masks compared to no masks in the community suggests probably little or no difference in interrupting the spread of influenza‐like illness (ILI)/COVID‐19 like illness (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.84 to 1.09; moderate‐certainty evidence), or laboratory‐confirmed influenza/SARS‐CoV‐2 (RR 1.01, 95% CI 0.72 to 1.42; moderate‐certainty evidence). Six trials were cluster‐RCTs, with all participants in the intervention clusters required to wear masks, thus assessing both source control and personal protection. In two trials the clusters were households with a member with new influenza; neither trial found any protective effect (RR 1.03 in 105 households (Canini 2010); RR 1.21 in 145 households (MacIntyre 2009). In two trials the clusters were college dormitories during the influenza season; neither trial found any reduction (RR 1.10 in 37 dormitories (Aiello 2012); RR 0.90 in three dormitories (Aiello 2010)). Two studies were conducted during the COVID‐19 pandemic and their addition had minimal impact on the pooled estimate of effect previously reported from the earlier studies focused on influenza (Abaluck 2022; Bundgaard 2021). We excluded Aiello 2010 from meta‐analysis since we did not consider 'randomisation' of three clusters to three arms was a proper randomised trial.

Less than half of the trials comparing masks with no masks addressed harms of mask wearing (Canini 2010; Cowling 2008; MacIntyre 2015; Suess 2012). Warmth, respiratory difficulties, humidity, and general discomfort were the most frequently reported adverse events. Neither of the RCTs conducted during the COVID‐19 pandemic directly assessed harms of mask wearing. More adults reported no harms compared to children.

In one trial cloth masks were associated with a significantly higher risk of both ILI and laboratory‐confirmed respiratory virus infection in healthcare workers (HCWs) (MacIntyre 2015). In addition, filtration capacity of the two‐ply cotton cloth masks was found to be only 3% and markedly less than with medical/surgical masks based on standardised particle testing. The authors suggested moisture retention, poor filtration, and penetration of the virus through the mask as plausible explanations for the increased risk of infection.

We did not find any randomised trials assessing the effectiveness of barrier interventions using a combination of masks, gloves, and gowns.

2. N95 respirators compared to medical/surgical masks

Comparisons between N95 respirators and medical/surgical masks, used as needed for exposure to at‐risk patients, for the outcomes of clinical respiratory illness and the outcome of laboratory‐confirmed influenza showed estimates of effect suggesting considerable uncertainty for any benefit of N95 respirators for the former outcome and probably little or no difference for the latter outcome. Five trials (four in healthcare settings and one in a household setting) compared N95/P2 respirators with medical/surgical masks. Pooling of three of these trials showed an estimate of effect suggesting considerable uncertainty as to whether there was any benefit comparing N95 respirators and medical/surgical face masks for the outcome of clinical respiratory illness (RR 0.70, 95% CI 0.45 to 1.10; very low‐certainty evidence), and that N95 respirators may make little or no difference for the outcome of ILI (RR 0.82, 95% CI 0.66 to 1.03; low‐certainty evidence), and probably little or no difference for the outcome of laboratory‐confirmed influenza (RR 1.10, 95% CI 0.90 to 1.34; moderate‐certainty evidence). The presence of imprecision (wide CIs) and heterogeneity, particularly for the more subjective and less precise outcomes of clinical respiratory illness and ILI compared to laboratory‐confirmed influenza infection, makes it difficult to assess whether there may be a benefit of either medical/surgical masks or N95/P2 respirators. Restricting the pooling to HCWs made no difference to the overall findings. The two trials with the largest event rates were quite consistent in their findings of no significant differences between N95 and medical/surgical masks for the outcomes of laboratory‐confirmed influenza and all laboratory‐confirmed viral infections (Loeb 2009; Radonovich 2019). Three of the trials contributing to this analysis were carried out by members of the same group (MacIntyre 2009; MacIntyre 2011; MacIntyre 2013).

In general, harms were poorly reported or not reported at all in trials comparing N95 respirators with surgical masks. General discomfort resulting in reduced wear adherence was the most frequently reported harm.

3. Hand hygiene compared to control

We found that the estimate of effect may offer a benefit for hand hygiene for the composite outcome 'acute respiratory infections (ARI) or ILI or influenza' (RR 0.89, 95% CI 0.83 to 0.94; low‐certainty evidence), and probably offers a benefit for the outcomes ARI alone (RR 0.86, 95% CI 0.81 to 0.90; moderate‐certainty evidence), and absenteeism (RR 0.64, 95% CI 0.58 to 0.71). An observed estimate of effect in favour of hand hygiene for laboratory‐confirmed influenza, but with wider CIs may be a consequence of smaller sample sizes in conjunction with a more rigorous outcome measure.

4. Hand hygiene + medical/surgical masks compared to control

The estimate of effect of combined hand hygiene and medical/surgical mask interventions compared to control in six (mostly small) trials suggested that the intervention may make little or no difference for the outcomes ILI (RR 1.03, 95% CI 0.77 to 1.37), and laboratory‐confirmed influenza (four trials) (RR 0.97, 95% CI 0.69 to 1.36).

5. Hand hygiene + medical/surgical masks compared to hand hygiene

We also found an estimate of effect suggesting that adding medical/surgical masks to hand hygiene compared to hand hygiene alone may make little or no difference for the outcomes ILI (RR 1.03, 95% CI 0.69 to 1.53; 3 trials), and laboratory‐confirmed influenza (RR 0.99, 95% CI 0.69 to 1.44).

6. Medical/surgical masks compared to other (non‐N95) masks

One trial found that medical/surgical masks were more effective than cloth masks at reducing the rate of ILI (RR 13.25, 95% CI 1.74 to 100.97) (MacIntyre 2015), but the extremely wide CIs make this finding difficult to interpret. One trial did not find a benefit from catechin‐treated masks over untreated masks on influenza infection rates (adjusted odds ratio (OR) 2.35, 95% CI 0.40 to 13.72; P = 0.34) (Ide 2016).

Harms of wearing masks were reported in 40.4% of HCWs using medical/surgical masks, and in 42.6% of those wearing cloth masks (P = 0.45) (MacIntyre 2015). The penetration of particles was higher in cloth masks (97%) compared to medical/surgical masks (44%).

7. Soap + water compared to sanitiser, and comparisons of different types of sanitiser

There were too few trials comparing different types of hand hygiene interventions to be certain of any true differences between soap and water, alcohol‐based hand sanitisers, or other types of interventions. Also, it is uncertain whether the incremental effect of adding virucidals or antiseptics to hand‐washing actually decreased the respiratory disease burden outside the confines of the rather atypical studies. The extra benefit may have been, at least in part, accrued by confounding additional routines.

8. Surface/object disinfection (with or without hand hygiene) compared to control

We identified six trials on surface/object disinfection (with or without hand hygiene), and although they were heterogeneous (and therefore could not be pooled), three of them showed a clear benefit compared to controls (Ban 2015; Carabin 1999; Ibfelt 2015).

We found no RCTs of nose disinfection, or disinfection of living quarters, as described in observational studies reported in Jefferson 2011.

9. Complex interventions compared to control

Four trials studied complex hygiene and sanitation interventions, all in low‐income country settings (Chard 2019; Hartinger 2016; Huda 2012; Najnin 2019). These trials could not be pooled due to the heterogeneity of the interventions and settings. All four trials found no significant differences between groups in the rates of viral respiratory illness.

10. Physical distancing/quarantine compared to control

We identified one trial that evaluated the effect of quarantine and found a reduction in influenza transmission to co‐workers when those with infected household members stayed home from work (Miyaki 2011). However, staying home increased their risk of being infected two‐fold. Two studies conducted during the COVID‐19 pandemic on SARS‐cov‐2 transmission showed (1) non‐inferiority of daily contact testing of school‐based contacts (intervention) compared to self‐isolation (control) (Young 2021); and (2) access to fitness centres with physical distancing and low population prevalence of SARS‐CoV‐2 infection did not increase risk of SARS‐cov‐2 infection (Helsingen 2021).

11. Eye protection compared to control

We only identified one trial of eye protection which was a preprint only (Fretheim 2022a).

12. Gargling compared to control

Three trials addressed the use of gargling in preventing respiratory infections (Goodall 2014; Ide 2014; Satomura 2005). Although the trials used a variety of liquids and different outcomes, pooling the results of the two trials that compared gargling with tap water versus control did not show a favourable effect in reducing URTIs (RR 0.91, 95% CI 0.63 to 1.31) (Goodall 2014; Satomura 2005). Two trials of mouthwash/nose rinse were conducted during the SARS‐cov‐2 pandemic in HCWs: Almanza‐Reyes 2021 compared silver mouth wash/nose rinse versus conventional mouthwashes and nose rinse; and Gutiérrez‐García 2022 compared neutral electrolysed water mouth and nose rinses versus no rinses. Both studies reported large protective effects of the intervention on SARS‐CoV‐2 infection with reported outcomes of  SARS‐C0V‐2 infection in 28.2% and 12.7% in the HCWs not using the interventions versus 1.8% and 1.2% in those using the intervention, despite the use of  full personal protective equipment (PPE) and the high outcome rates raise questions about risk of bias, and no data were provided about baseline rates in other settings with full use of PPE.

13. Virucidal tissues compared to control

Two reports (three trials) identified in Jefferson 2011 studied the effect of virucidal tissues compared to placebo or no tissues (Farr 1988a; Farr 1988b; Longini 1988). These trials found no differences in infection rates and could not be pooled.

Overall completeness and applicability of evidence

Several features need consideration before making generalisations based on the included studies.

The settings of the included studies, which were conducted over five decades, were heterogeneous and ranged from suburban schools, Carabin 1999, to emergency departments, intensive care units, and paediatric wards, Loeb 2009, in high‐income countries; slums in low‐income countries (Luby 2005); and an upper Manhattan immigrant Latino neighbourhood (Larson 2010). Few attempts were made to obtain socio‐economic diversity by (for example) involving more schools in the evaluations of the same programme. We identified only a few studies from low‐income countries, where the vast majority of the burden of ARIs lies and where inexpensive interventions are so critical. Additionally, limited availability of over‐the‐counter medications and national universal comprehensive health insurance provided with consequent physician prescription of symptomatic treatment may further limit the generalisability of findings.

The included trials generally reported few events and were conducted mostly during non‐epidemic periods with the exception of the trials carried out during the influenza H1N1 and SARS‐CoV‐2 pandemics. The large study by Radonovich 2019 is an exception as it crossed over two of the highest reporting years for influenza in the USA between 2010 and 2017 (Elflein 2019). None of the trials were conducted during pandemics of SARS‐CoV‐1or in outbreaks of Middle East respiratory syndrome (MERS).

Of the trials assessing the effect of masks, six were carried out in those at greater exposure (i.e. HCWs) (Jacobs 2009; Loeb 2009; MacIntyre 2011; MacIntyre 2013; MacIntyre 2015; Radonovich 2019). None of these studies included HCWs undertaking aerosol‐generating procedures, for which the World Health Organization (WHO) currently recommends the N95 or equivalent mask. Three trials on hand hygiene interventions were carried out in nursing homes, and included HCWs (McConeghy 2017; Temime 2018; Yeung 2011). The scarcity of RCTs on HCWs limits the generalisability of such results.

The variable quality of the methods of some studies is striking. Incomplete or no reporting of randomisation (Turner 2004a), blinding (Farr 1988a; Farr 1988b), numerators and denominators (Carabin 1999; Kotch 1994), interventions, and cluster coefficients in the relevant trials (Carabin 1999), led to a considerable loss of information. Potential biases were often not discussed.

Inappropriate placebos caused design problems. In some studies the placebo probably carried sufficient effect to dilute the intervention effects (Longini 1988). Two valiant attempts with virucidal tissues probably failed because placebo handkerchiefs were impregnated with a dummy compound that stung the users' nostrils (Farr 1988a; Farr 1988b).

Some studies used impractical interventions. Volunteers subjected to the intervention hand cleaner (organic acids) were not allowed to use their hands between cleaning and virus challenge, so the effect of normal use of the hands on the intervention remains unknown (Turner 2004a; Turner 2004b). Two per cent aqueous iodine painted on the hands, although a successful antiviral intervention, causes unacceptable cosmetic staining, which is impractical for all but those at the highest risk of epidemic contagion (Gwaltney 1980).

Adherence with interventions, especially educational programmes, was a problem for many studies despite the importance of many such low‐cost interventions. Adherence with mask wearing varied; it was generally around 60% to 80%, but was reported to be as low as 40% (see Table 4). Overall, the logistics of carrying out trials that involve sustained behaviour change are demanding, particularly in challenging settings such as immigrant neighbourhoods or students' halls of residence.

The identified trials provided sparse and unsystematic data on adverse effects of the intervention, and few of the RCTs measured or reported adherence with the intervention, which is especially important for the use of medical/surgical masks or N95 respirators. No studies investigated how the level of adherence may have influenced the effect size.

We identified one study assessing the effects of eye protection (Fretheim 2022a), and we identified three studies on physical distancing/quarantine (Helsingen 2021; Miyaki 2011; Young 2021). The dearth of evidence and predominant setting of seasonal viral circulation limits generalisability of our findings to other contexts and any future epidemics due to other respiratory viruses such as the COVID‐19 pandemic although there have been increasing numbers of RCTs and cluster‐RCTs in the latter setting which are adding to the evidence base.

The two recent small trials from Mexico assessing local mouth/nose rinses airways prophylactic as interventions treatments report large but uncertain reductions in transmission to healthcare workers which warrant further study and replication by other investigator (Almanza‐Reyes 2021; Gutiérrez‐García 2022).

Certainty of the evidence

We found the available evidence base identified through our search processes to be of variable quality. Reporting of sequence generation and allocation concealment were poor in 30% to 50% of studies across the categories of intervention comparisons. Given the nature of the intervention comparison, blinding of treatment allocation after randomisation was rarely achieved. Although blinding of outcome assessment is highly feasible and desirable, most outcomes were assessed by self‐reports. Outcomes in some studies were poorly defined, with a lack of clarity as to the possible aetiological agents (bacterial versus viral). Some studies used laboratory‐confirmed outcomes, both adding precision and avoiding indirectness by having an accurate outcome measure and lowering the risk of bias (see Table 12 for heterogeneity of trial outcome definitions). We found no evidence of selective reporting of outcomes within the included studies. We believe publication bias is unlikely, as the included studies demonstrated a range of effects, both positive and negative, over all study sizes. The variable quality of the studies hampers drawing any firm conclusions.

Potential biases in the review process

The non‐drug (and often locally manufactured) nature of most of the interventions in this review, the lack of effective regulation in some settings, and the possible endless number of manufacturers make it difficult to gauge the existence of unpublished data. Non‐drug interventions typically have no or very loose regulation.

In this 2022 update, we again focused on RCTs and cluster‐RCTs, providing a higher level of evidence compared with the previous version of the review, which also meta‐analysed observational studies when appropriate (Jefferson 2011). However, many of the trials were small and hence underpowered, and at high or unclear risk of bias due to poor reporting of methods and lack of blinding. The populations, outcomes, comparators, and interventions tested were heterogeneous.

Due to the urgency of this update in the context of the COVID‐19 pandemic, we did not contact trial authors to request missing data. This means that we have not considered studies that included other non‐respiratory infections, and did not provide stratified data by type of infection.

Agreements and disagreements with other studies or reviews

Several reviews of RCTs have found broadly similar results to this review for face masks. In a meta‐analysis comparing surgical masks with N95 respirators, Smith 2016 pooled three trials and found an estimate of effect suggesting no difference for laboratory‐confirmed respiratory infections (OR 0.89, 95% CI 0.64 to 1.24) or ILI (OR 0.51, 95% CI 0.19 to 1.41) (Loeb 2009; MacIntyre 2011; MacIntyre 2013). A similar meta‐analysis, Offeddu 2017, based on two trials concluded that masks (either N95/P2 respirators or medical/surgical masks) were effective against clinical respiratory infections (RR 0.59, 95% CI 0.46 to 0.77) and ILI (RR 0.34, 95% CI 0.14 to 0.82) (MacIntyre 2011; MacIntyre 2015). Pooling of two studies (MacIntyre 2011; MacIntyre 2013) also found an estimate of effect that favoured N95 respirators to medical/surgical masks for clinical respiratory infections (RR 0.47, 95% CI 0.36 to 0.62), but not for ILI, (RR 0.59, 95% CI 0.27 to 1.28) based on three studies (Loeb 2009: MacIntyre 2011; MacIntyre 2013). The outcome of clinical respiratory infection is considered to be the most subjective and least precise outcome.

A recent meta‐analysis included five trials comparing N95/P2 respirators with medical/surgical masks and found no difference between groups for either influenza (RR 1.09, 95% CI 0.92 to 1.28), or respiratory viral infections (RR 0.89, 95% CI 0.70 to 1.11) (Long 2020). By excluding Loeb 2009 (an open, non‐inferiority RCT that compared medical/surgical masks with N95 respirators in protecting HCWs against influenza), the authors reported a significant protective effect against viral infections (RR 0.61, 95% CI 0.39 to 0.98). The authors do not report a rationale for the exclusion in the sensitivity analysis, and do not report on exclusion of the studies with low weighting, which arguably would be more relevant in a sensitivity analysis. The two trials that make up 96% of the weighting demonstrated no significant differences in the outcome events (Loeb 2009; Radonovich 2019). A recent meta‐analysis of four RCTs adjusting for clustering, which compared N95 respirators with the use of medical/surgical  masks, found pooled estimates of effect that did not demonstrate any difference in any laboratory‐confirmed viral respiratory infection (OR 1.06, 95% CI 0.90 to 1.25), laboratory‐confirmed influenza (OR 0.94, 95% CI 0.73 to 1.20), or clinical respiratory illness (OR 1.49, 95% CI 0.98 to 2.28), with the evidence profile suggesting that there was greater imprecision and inconsistency in the outcome of clinical respiratory illness (Bartoszko 2020). Moreover, in another recent systematic review that assessed the effectiveness of personal protective and environmental measures in non‐healthcare settings (funded by the WHO), 10 RCTs reporting estimates of the effectiveness of face masks in reducing laboratory‐confirmed influenza virus infections in the community were identified (Xiao 2020). The evidence from these RCTs suggested that the use of face masks either by infected persons or by uninfected persons does not have a substantial effect on influenza transmission.

The findings from several systematic reviews and meta‐analyses over the last decade have not demonstrated any difference in the clinical effectiveness of N95 respirators or equivalent compared to the use of surgical masks when used by HCWs in multiple healthcare settings for the prevention of respiratory virus infections, including influenza.

Reviews based on observational studies have usually found a stronger protective effect for face masks, but have important biases. The review by Chu 2020 did not consider RCTs of influenza transmission, but only the observational studies examining impact on SARS, MERS, or SARS‐CoV‐2. For N95 masks versus no mask in HCWs, there was a large protective effective with an OR of 0.04 (95% CI 0.004 to 0.30); for surgical masks versus no masks, there was an OR of 0.33 (0.17 to 0.61) overall, but four of these studies were in healthcare settings. Chu 2020 has been criticised for several reasons: use of an outdated 'Risk of bias' tool; inaccuracy of distance measures; and not adequately addressing multiple sources of bias, including recall and classification bias and in particular confounding. Confounding is very likely, as preventive behaviours such as mask use, social distancing, and hand hygiene are correlated behaviours, and hence any effect estimates are likely to be overly optimistic.

The two RCTs of medical/surgical masks during the SARS‐CoV‐2 pandemic found uncertain evidence of a small or no effect (Abaluck 2022; Bundgaard 2021). The study by Abaluck 2022 found a statistically significant benefit of masks versus no masks for COVID‐like‐illness, however, this study was rated at high risk of bias for five of the six domains due to issues including baseline imbalance, subjective outcome assessment and incomplete follow‐up across the groups. Despite this study contributing 45% of the weight towards the meta‐analysis of influenza/COVID‐like‐illness for masks versus no masks, the updated conclusions from the analysis strengthened around little or no effect of mask use.

Also based on observational studies, Jefferson 2011 found a protective effect of wearing surgical masks with hygienic measures compared to not wearing masks in the SARS 2003 outbreak (OR 0.32, 95% CI 0.26 to 0.39). However, the evidence was based on case‐control studies carried out during the outbreak. There was some additional but very limited supportive evidence from the cohort studies in Jefferson 2011.

Although the use of eye protection and physical distancing measures are widely believed to be effective in reducing transmission of respiratory viruses and mitigating the impact of an influenza pandemic, we found only one trial investigating the role of self‐quarantine in reducing the incidence of H1N1 influenza events in the workplace, and no trials examining the effect of eye protection. The evidence for these measures was derived largely from observational studies and simulation studies, and the overall certainty of supporting evidence is relatively low. The finding of limited evidence evaluating these interventions was also consistent with a recent review funded by the WHO for the preparation of its guidelines on the use of non‐pharmaceutical interventions for pandemic influenza in non‐medical settings (Fong 2020).

There are several previous systematic reviews on hand hygiene and respiratory infections. Five of them reviewed the evidence in a community setting (Moncion 2019; Rabie 2006; Saunders‐Hastings 2017; Warren‐Gash 2013: Wong 2014), and three focused on children (Mbakaya 2017; Willmott 2016; Zivich 2018). The earliest review in 2006 included eight studies, three of which were RCTs (Rabie 2006). The pooled estimate of seven studies was described as “indicative” of the effect of hand hygiene, but the studies were of poor quality. The Warren‐Gash 2013 review included 16 studies (10 of which were RCTs) and reported mixed and inconclusive results. A 2014 review identified 10 RCTs and reported that the combination of hand hygiene with face masks in high‐income countries (five trials) significantly reduced the incidence of laboratory‐confirmed influenza and ILI, whilst hand hygiene alone did not (Wong 2014). This significant reduction in laboratory‐confirmed influenza and ILI for hand hygiene and face masks may have been based on the raw numbers without adjusting for any clustering effects in the included cluster trials, which produced inappropriately narrow CIs, and possibly biased treatment effect estimates. Moreover, trials from the low‐income countries were not included in the review, and this significant effect was not demonstrated when all the trials identified in the review were combined. The Saunders‐Hastings 2017 review of studies evaluating the effectiveness of personal protective measures in interrupting pandemic influenza transmission only identified two RCTs (Azor‐Martinez 2014; Suess 2012), which reported a significant effect of hand hygiene. The Moncion 2019 review identified seven RCTs of hand hygiene compared to control, with mixed results for preventing the transmission of laboratory‐confirmed or possible influenza. Systematic reviews of RCTs of hand hygiene interventions amongst children, Mbakaya 2017 and Willmott 2016, or at a non‐clinical workplace, Zivich 2018, identified heterogeneous trials with quality problems including small numbers of clusters and participants, inadequate randomisation, and self‐reported outcomes. Evidence of impact on respiratory infections was equivocal.

A rapid search for other systematic reviews of RCTs was conducted in September 2022, and none of high quality were found.

Authors' conclusions

Implications for practiceThe evidence summarised in this review on the use of masks is largely based on studies conducted during traditional peak respiratory virus infection seasons up until 2016. Two relevant randomised trials conducted during the COVID‐19 pandemic have been published, but their addition had minimal impact on the overall pooled estimate of effect. The observed lack of effect of mask wearing in interrupting the spread of influenza‐like illness (ILI) or influenza/COVID‐19 in our review has many potential reasons, including: poor study design; insufficiently powered studies arising from low viral circulation in some studies; lower adherence with mask wearing, especially amongst children; quality of the masks used; self‐contamination of the mask by hands; lack of protection from eye exposure from respiratory droplets (allowing a route of entry of respiratory viruses into the nose via the lacrimal duct); saturation of masks with saliva from extended use (promoting virus survival in proteinaceous material); and possible risk compensation behaviour leading to an exaggerated sense of security (Ammann 2022; Brosseau 2020; Byambasuren 2021; Canini 2010; Cassell 2006; Coroiu 2021; MacIntyre 2015; Rengasamy 2010; Zamora 2006).Our findings show that hand hygiene has a modest effect as a physical intervention to interrupt the spread of respiratory viruses, but several questions remain. First, the high heterogeneity between studies may suggest that there are differences in the effect of different interventions. The poor reporting limited our ability to extract the information needed to assess any 'dose response' relationship, and there are few head‐to‐head trials comparing hand hygiene materials (such as alcohol‐based sanitiser or soap and water). Second, the sustainability of hand hygiene is unclear where participants in some studies achieved 5 to 10 hand‐washings per day, but adherence may have diminished with time as motivation decreased, or due to adverse effects from frequent hand‐washing. Third, there is little evidence about the effectiveness of combinations of hand hygiene with other interventions, and how those are best introduced and sustained. Finally, some interventions were intensively implemented within small organisations, and involved education or training as a component, and the ability to scale these up to broader interventions is unclear. Our findings with respect to hand hygiene should be considered generally relevant to all viral respiratory infections, given the diverse populations where transmission of viral respiratory infections occurs. The participants were adults, children and families, and multiple congregation settings including schools, childcare centres, homes, and offices. Most respiratory viruses, including the pandemic SARS‐CoV‐2, are considered to be predominantly spread via respiratory particles of varying size or contact routes, or both (WHO 2020c). Data from studies of SARS‐CoV‐2 contamination of the environment based on the presence of viral ribonucleic acid and infectious virus suggest significant fomite contamination (Lin 2022; Onakpoya 2022b; Ong 2020; Wu 2020). Hand hygiene would be expected to be beneficial in reducing the spread of SARS‐CoV‐2 similar to other beta coronaviruses (SARS‐CoV‐1, Middle East respiratory syndrome (MERS), and human coronaviruses), which are very susceptible to the concentrations of alcohol commonly found in most hand‐sanitiser preparations (Rabenau 2005; WHO 2020c). Support for this effect is the finding that poor hand hygiene, despite the use of full personal protective equipment (PPE), was independently associated with an increased risk of SARS‐CoV‐2 transmission to healthcare workers in a retrospective cohort study in Wuhan, China in both a high‐risk and low‐risk clinical unit for patients infected with COVID‐19 (Ran 2020). The practice of hand hygiene appears to have a consistent effect in all settings, and should be an essential component of other interventions.The highest‐quality cluster‐RCTs indicate that the most effect on preventing respiratory virus spread from hygienic measures occurs in younger children. This may be because younger children are least capable of hygienic behaviour themselves (Roberts 2000), and have longer‐lived infections and greater social contact, thereby acting as portals of infection into the household (Monto 1969). Additional benefit from reduced transmission from them to other members of the household is broadly supported by the results of other study designs where the potential for confounding is greater.Routine long‐term implementation of some of the interventions covered in this review may be problematic, particularly maintaining strict hygiene and barrier routines for long periods of time. This would probably only be feasible in highly motivated environments, such as hospitals. Many of the trial authors commented on the major logistical burdens that barrier routines imposed at the community level. However, the threat of a looming epidemic may provide stimulus for their inception.

Implications for researchPublic health measures and physical interventions can be highly effective to interrupt the spread of respiratory viral infections, especially when they are part of a structured and co‐ordinated programme that includes instruction and education, and when they are delivered together and with high adherence. Our review has provided important insights into research gaps that need to be addressed with respect to these physical interventions and their implementation and have been brought into a sharper focus as a result of the COVID‐19 pandemic. The 2014 WHO document 'Infection prevention and control of epidemic ‐ and pandemic‐prone acute respiratory infections in health care' identified several research gaps as part of their GRADE assessment of their infection prevention and control recommendations, which remain very relevant (WHO 2014). Research gaps identified during the course of our review and the WHO 2014 document may be considered from the perspective of both general and specific themes.A general theme identified was the need to provide outcomes with explicitly defined clinical criteria for acute respiratory infections (ARIs) and discrete laboratory‐confirmed outcomes of viral ARIs using molecular diagnostic tools which are now widely available. Our review found large disparities between studies with respect to the clinical outcome events, which were imprecisely defined in several studies, and there were differences in the extent to which laboratory‐confirmed viruses were included in the studies that assessed them. Another general theme identified was the lack of consideration of sociocultural factors that might affect adherence with the interventions, especially those employed in the community setting. A prime example of this latter point was illustrated by the observations of the use of masks versus mask mandates during the COVID‐19 pandemic. In addition, the cost and resource implications of the physical interventions employed in different settings would have important relevance for low‐ to middle‐income countries. Resources have been a major issue with the COVID‐19 pandemic, with global shortages of several components of PPE. Several specific research gaps related to physical interventions were identified within the WHO 2014 document and are congruent with many of the findings of this 2022 update, including the following: transmission dynamics of respiratory viruses from patients to healthcare workers during aerosol‐generating procedures; a continued lack of precision with regards to defining aerosol‐generating procedures; the safety of cohorting of patients with the same suspected but unconfirmed diagnosis in a common unit or ward with patients infected with the same known pathogen in healthcare settings; the optimal duration of the use of physical interruptions to prevent spread of ARI viruses; use of spatial separation or physical distancing (in healthcare and community settings, respectively) alone versus spatial separation or physical distancing with the use of other added physical interventions coupled with examining discrete distance parameters (e.g. one metre, two metres, or > two metres); the effectiveness of respiratory etiquette (i.e. coughing/sneezing into tissues or a sleeved bent elbow); the effectiveness of triage and early identification of infected individuals with an ARI in both hospital and community settings; the utility of entrance screening to healthcare facilities; use of frequent disinfection techniques appropriate to the setting (high‐touch surfaces in the environment, gargling with oral disinfectants, and virucidal tissues or clothing) alone or in combination with facial masks and hand hygiene; the use of visors, goggles or other eyewear; the use of ultraviolet light germicidal irradiation for disinfection of air in healthcare and selected community settings; the use of air scrubbers and /or high‐efficiency particulate absorbing filters and the use of widespread adherence with effective vaccination strategies.There is a clear requirement to conduct large, pragmatic trials to evaluate the best combinations in the community and in healthcare settings with multiple respiratory viruses and in different sociocultural settings. Randomised controlled trials (RCTs) with a pragmatic design, similar to the Luby 2005 trial or the Bundgaard 2020 trial, should be conducted whenever possible. Similar to what has been observed in pharmaceutical interventions where multiple RCTs were rapidly and successfully completed during the COVID‐19 pandemic, proving they can be accomplished, there should be a deliberate emphasis and directed funding opportunities provided to conduct well‐designed RCTs to address the effectiveness of many of the physical interventions in multiple settings and populations, especially in those most at risk, and in very specific well‐defined populations with monitoring of the adherence to the interventions. Several specific research gaps deserve expedited attention and may be highlighted within the context of the COVID‐19 pandemic. The use of face masks in the community setting represents one of the most pressing needs to address, given the polarised opinions around the world, and the increasing concerns over widespread microplastic pollution from the discarding of masks (Shen 2021). Both broad‐based ecological studies, adjusting for confounding and high quality RCTs, may be necessary to determine if there is an independent contribution to their use as a physical intervention, and how they may best be deployed to optimise their contribution. The type of fabric and weave used in the face mask is an equally pressing concern, given that surgical masks with their cotton‐polypropylene fabric appear to be effective in the healthcare setting, but there are questions about the effectiveness of simple cotton masks. In addition, any masking intervention studies should focus on measuring not only benefits but also adherence, harms, and risk compensation if the latter may lead to a lower protective effect. In addition, although the use of medical/surgical masks versus N95 respirators demonstrates no differences in clinical effectiveness to date, their use needs to be further studied within the context of a well‐designed RCT in the setting of COVID‐19, and with concomitant measurement of harms, which to date have been poorly studied. The recently published Loeb RCT conducted over a prolonged course in the current pandemic has provided the only evidence to date in this area (Loeb 2022).Physical distancing represents another major research gap which needs to be addressed expediently, especially within the context of the COVID‐19 pandemic setting as well as in future epidemic settings. The use of quarantine and screening at entry ports needs to be investigated in well‐designed, high‐quality RCTs given the controversies related to airports and travel restrictions which emerged during the COVID‐19 pandemic. We found only one RCT investigating quarantine, and no trials of screening at entry ports or physical distancing. Given that these and other physical interventions are some of the primary strategies applied globally in the face of the COVID‐19 pandemic, future trials of high quality should be a major global priority to be  conducted within the context of this pandemic, as well as in future epidemics with other respiratory viruses of less virulence.The variable quality and small scale of some studies is known from descriptive studies (Aiello 2002; Fung 2006; WHO 2006b), and systematic reviews of selected interventions (Meadows 2004). In summary, more high‐quality RCTs are needed to evaluate the most effective strategies to implement successful physical interventions in practice, both on a small scale and at a population level. It is very unfortunate that more rigorous planning, effort and funding was not provided during the current COVID‐19 pandemic towards high‐quality RCTs of the basic public health measures. Finally, we emphasise that more attention should be paid to describing and quantifying the harms of the interventions assessed in this review, and their relationship with adherence.

What's new

History

Protocol first published: Issue 4, 2006
Review first published: Issue 4, 2007

Notes

In Issue 1, 2010, the title of the review was changed from 'Interventions for the interruption or reduction of the spread of respiratory viruses' to 'Physical interventions to interrupt or reduce the spread of respiratory viruses'.

The original review was subsequently published as Jefferson T, Foxlee R, Del Mar C, Dooley L, Ferroni E, Hewak B, Prabhala A, Nair S, Rivetti A. Physical interventions to interrupt or reduce the spread of respiratory viruses: systematic review. BMJ 2008;336:77‐80 and Jefferson T, Del Mar C, Dooley L, Ferroni E, Al‐Ansary LA, Bawazeer GA, van Driel ML, Foxlee R, Rivetti A. Physical interventions to interrupt or reduce the spread of respiratory viruses: systematic review. BMJ 2009;339:b3675. DOI: 10.1136/bmj.b3675.

Acknowledgements

AcknowledgementsThis 2022 review update is funded by the National Institute for Health and Care Research (NIHR) ESP Incentive Award Scheme NIHR150879. The views expressed are those of the authors and not necessarily those of the NIHR or the Department of Health and Social Care.We wish to acknowledge the late Chris del Mar for his substantial contributions as an author on previous versions of this review. We also thank Sarah Thorning for designing and updating searches from the 2011 publication to the 2020 publication. We thank Jessika Wejfalk for translating the funding source in a Danish trial in this 2022 update.The following people conducted the editorial process for this 2022 update:Sign‐off Editor (final editorial decision): Michael Brown (Michigan State University College of Human Medicine, USA).Managing Editor (selected peer reviewers, collated peer reviewer comments, provided editorial guidance to authors): Fiona Russell (Bond University, Australia).Contact Editor (assessed peer review comments and recommended an editorial decision): Allen Cheng (Monash University, Australia).Statistical Editor (provided comments): Teresa Neeman (Biological Data Science Institute, Australian National University, Australia).Copy Editor (copy‐editing and production): Heather Maxwell.Peer reviewers (provided comments and recommended an editorial decision):Clinical/content review: Roderick P. Venekamp.Consumer review: Janet Wale (Independent consumer representative).Methods review: Leslie Choi (Evidence Synthesis Development Editor, Cochrane Central Executive Team).

Competing interests

Declarations of interestLAA: has declared that they have no conflict of interest. GAB: reports working at King Saud University, Medical City, Riyadh, Saudi Arabia as clinical faculty in the College of Pharmacy, collaborating with pharmacy services to provide clinical pharmacy services in primary care clinics (non‐paid). EMB: has declared that they have no conflict of interest. JC: is an Information Specialist at the Cochrane Acute Respiratory Infections Group but was not involved in the editorial process for this review. JMC: has held or holds peer reviewed grants from the Canadian Institutes for Health Research (CIHR) on acute and primary care preparedness for COVID‐19 in Alberta, Canada and has received components of funding from a CIHR funded study via McMaster University for a randomised trial of medical masks versus N95 respirators for preventing COVID‐19 amongst healthcare workers. He has also been engaged in WHO funded studies using integrated human factors and ethnography approaches to identify and scale innovative IPC guidance implementation supports in primary care with a focus on low‐resource settings and using drone aerial systems to deliver medical supplies and PPE to remote First Nations communities during the COVID‐19 pandemic and was the primary local Investigator for a Staphylococcus aureus vaccine study funded by Pfizer for which all funding was provided only to the University of Calgary. He has received travel support from the Centers for Disease Control and Prevention (CDC) to attend an Infection Control Think Tank Meeting and from bioMerieux Canada to speak at a symposium on antimicrobial resistance co‐hosted by the University of Toronto and bioMerieux Canada. He also reports being a member and Chair of the WHO Infection Prevention and Control Research and Development Expert Group for COVID‐19 and reports being a member of the WHO Health Emergencies Programme (WHE) Ad‐hoc COVID‐19 IPC Guidance Development Group, both of which provide multidisciplinary advice to the WHO, for which no funding is received and from which no funding recommendations are made for any WHO contracts or grants. He reports declaring an opinion on topics in this review in Clinical Microbiology and Infection and Antimicrobial Resistance and Infection Control; reports being engaged as a co‐author on a randomised trial of medical masks versus N95 respirators for preventing COVID‐19 amongst healthcare workers published in the Annals of Internal Medicine in 2022 and mentioned in this current Cochrane Review, but no extraction or risk of bias assessment or data pooling or other assessment was undertaken by him nor will it be in any future updates. He has also been a member of the W21C since 2004 and served as its Medical Director from 2012‐2022. W21C is a not‐for‐profit healthcare systems research and innovation initiative based in the University of Calgary’s O'Brien Institute for Public Health and the Calgary Zone of Alberta Health Services. He reports working as an Infectious Diseases Consultant at Alberta Health Services, Calgary, Canada. LD: is a Managing Editor at the Cochrane Acute Respiratory Infections Group but was not involved in the editorial process for this review. EF: has declared that they have no conflict of interest. PG: reports a grant from the National Health and Medical Research Council, Australia. TH: is a member of the Cochrane Stroke Group Editorial Board but was not involved in the editorial process for this review. TJ: reports declaring an opinion on the topic of the review in articles for popular media. TJ is an Editor at the Cochrane Acute Respiratory Infections Group but was not involved in the editorial process for this review. See full statement here: https://restoringtrials.org/competing-interests-tom-jefferson/ MAJ: reports a grant from the National Institute for Health Research, UK. MAJ is Co‐ordinating Editor at the Cochrane Acute Respiratory Infections Group but was not involved in the editorial process for this review. MLvD: reports being a primary care panel member for the National COVID‐19 Clinical Evidence Taskforce, Australia. MLvD is Deputy Co‐ordinating Editor at the Cochrane Acute Respiratory Infections Group but was not involved in the editorial process for this review.

References

1. AbaluckJ, KwongLH, StyczynskiA, HaqueA, KabirMA, Bates-JefferysE, et al. Impact of community masking on COVID-19: a cluster-randomized trial in Bangladesh. Science2022;375(6577):eabi9069. [DOI: 10.1126/science.abi9069]PMC903694234855513 doi:10.1126/science.abi9069 PubMed
2. Aelami MH, Khajehdalouee M, Yagoubian H, Amel Jamahdar S, Pittet D. Implementation of an educational intervention among Iranian hajj pilgrims for the prevention of influenza-like illness. Antimicrobial Resistance and Infection Control2015;4(1):48.
3. AielloAE, MurrayGF, PerezV, CoulbornRM, DavisBM, UddinM, et al. Mask use, hand hygiene, and seasonal influenza-like illness among young adults: a randomized intervention trial. Journal of Infectious Diseases2010;201(4):491-8. 10.1086/65039620088690 doi:10.1086/650396 PubMed
4. Aiello AE, PerezV, Coulborn RM, DavisBM, Uddin M, Monto AS. Facemasks, hand hygiene, and influenza among young adults: a randomized intervention trial. PLOS One2012;7(1):e29744. [CTG: NCT00490633]10.1371/journal.pone.0029744PMC326625722295066 doi:10.1371/journal.pone.0029744 PubMed
5. AlfelaliM, HaworthEA, BarasheedO, BadahdahAM, BokharyH, TashaniM, et al. Facemask against viral respiratory infections among Hajj pilgrims: a challenging cluster-randomized trial. PLOS One2020;15(10):e0240287. [DOI: 10.1371/journal.pone.0240287]PMC755331133048964 doi:10.1371/journal.pone.0240287 PubMed
6. Almanza-ReyesH, MorenoS, Plascencia-LópezI, Alvarado-VeraM, Patrón-RomeroL, BorregoB, et al. Evaluation of silver nanoparticles for the prevention of SARS-CoV-2 infection in health workers: in vitro and invivo. PLOS One2021;16(8):e0256401. [DOI: 10.1371/journal.pone.0256401]PMC837577434411199 doi:10.1371/journal.pone.0256401 PubMed
7. AlzaherAA, Almudarra SS, MustafaMH, Gosadi IM. The importance of hand hygiene education on primary schoolgirls’ absence due to upper respiratory infections in Saudi Arabia. Saudi Medical Journal2018;39(10):1044-9. [DOI: 10.15537/smj.2018.10.23344]PMC620102930284589 doi:10.15537/smj.2018.10.23344 PubMed
8. Arbogast JW, Moore-SchiltzL, JarvisWR, Harpster-HagenA, HughesJ, ParkerA. Impact of a comprehensive workplace hand hygiene program on employer health care insurance claims and costs, absenteeism, and employee perceptions and practices. Journal of Occupational and Environmental Medicine2016;58(6):e231-40. 10.1097/JOM.0000000000000738PMC488364327281645 doi:10.1097/JOM.0000000000000738 PubMed
9. AshrafS, IslamM, UnicombL, RahmanM, WinchPJ, ArnoldBF, et al. Effect of improved water quality, sanitation, hygiene and nutrition interventions on respiratory illness in young children in rural Bangladesh: a multi-arm cluster-randomized controlled trial. American Journal of Tropical Medicine and Hygiene2020;102(5):1124-30. [DOI: 10.4269/ajtmh.19-0769]PMC720458832100681 doi:10.4269/ajtmh.19-0769 PubMed
10. Azor-MartinezE, Cobos-CarrascosaE, Seijas-VazquezML, Fernández-SánchezC, StrizziJM, Torres-AlegreP, et al. Hand hygiene program decreases school absenteeism due to upper respiratory infections. Journal of School Health2016;86(12):873-81. 10.1111/josh.1245427866386 doi:10.1111/josh.12454 PubMed
11. Azor-MartinezE, Yui-HifumeR, Muñoz-VicoFJ, Jimenez-NogueraE, StrizziJM, Martinez-MartinezI, et al. Effectiveness of a hand hygiene program at child care centers: a cluster randomized trial. Pediatrics2018;142(5):e20181245. 10.1542/peds.2018-124530297500 doi:10.1542/peds.2018-1245 PubMed
12. BanHQ, LiT, ShenJ, LiJ, PengPZ, YeHP, et al. Effects of multiple cleaning and disinfection interventions on infectious diseases in children: a group randomized trial in China. Biomedical and Environmental Sciences2015;28(11):779-87. 10.3967/bes2015.10926695356 doi:10.3967/bes2015.109 PubMed
13. BarasheedO, AlmasriN, BadahdahAM, HeronL, TaylorJ, McPheeK, et al, Hajj Research Team. Pilot randomised controlled trial to test effectiveness of facemasks in preventing influenza-like illness transmission among Australian hajj pilgrims in 2011. Infectious Disorders Drug Targets2014;14(2):110-6. [DOI: 10.2174/1871526514666141021112855]25336079 doi:10.2174/1871526514666141021112855 PubMed
14. BiswasD, AhmedM, RoguskiK, GhoshPK, ParveenS, NizameFA, et al. Effectiveness of a behavior change intervention with hand sanitizer use and respiratory hygiene in reducing laboratory-confirmed influenza among schoolchildren in Bangladesh: a cluster randomized controlled trial. American Journal of Tropical Medicine and Hygiene2019;101(6):1446-55. [DOI: 10.4269/ajtmh.19-0376]PMC689685531701861 doi:10.4269/ajtmh.19-0376 PubMed
15. BundgaardH, BundgaardJS, Raaschou-PedersenDE, BuchwaldCvon, TodsenT, Boesgaard NorskJ, et al. Effectiveness of adding a mask recommendation to other public health measures to prevent SARS-CoV-2 infection in Danish mask wearers: a randomized controlled trial. Annals of Internal Medicine2021;174(3):335-43. [DOI: 10.7326/M20-6817]PMC770721333205991 doi:10.7326/M20-6817 PubMed
16. Canini L, Andreoletti L, FerrariP, D’AngeloR, Blanchon T, Lemaitre M, et al. Surgical mask to prevent influenza transmission in households: a cluster randomized trial. PLOS One2010;5(11):e13998. [DOI: 10.1371/journal.pone.0013998]PMC298443221103330 doi:10.1371/journal.pone.0013998 PubMed
17. CarabinH, GyorkosTW, SotoJC, JosephL, PaymentP, ColletJP. Effectiveness of a training program in reducing infections in toddlers attending day care centers. Epidemiology1999;10(3):219-27. 10230828 PubMed
18. ChardAN, Garn JV, ChangHW, Clasen T, FreemanMC. Impact of a school-based water, sanitation, and hygiene intervention on school absence, diarrhea, respiratory infection, and soil-transmitted helminths: results from the WASH HELPS cluster-randomized trial. Journal of Global Health2019;9(2):1-14. [DOI: 10.7189/jogh.09.020402]PMC665700331360445 doi:10.7189/jogh.09.020402 PubMed
19. CorreaJC, PintoD, SalasLA, CamacchoJC, RondonM, QuinteroJ. A cluster-randomized controlled trial of handrubs for prevention of infectious diseases among children in Colombia. Journal of Public Health2012;31(6):476-84. 10.1590/s1020-4989201200060000522858814 doi:10.1590/s1020-49892012000600005 PubMed
20. CowlingBJ, FungRO, ChengCK, FangVJ, ChanKH, SetoWH, et al. Preliminary findings of a randomized trial of non-pharmaceutical interventions to prevent influenza transmission in households. PLOS One2008;3(5):e2101. 10.1371/journal.pone.0002101PMC236464618461182 doi:10.1371/journal.pone.0002101 PubMed
21. CowlingBJ, ChanKH, FangVJ, ChengCK, FungROP, WaiW, et al. Facemasks and hand hygiene to prevent influenza transmission in households. A randomized trial. Annals of Internal Medicine2009;151(7):437-46. 10.7326/0003-4819-151-7-200910060-0014219652172 doi:10.7326/0003-4819-151-7-200910060-00142 PubMed
22. DiVitaMA, Khatun-e-JannatK, IslamM, Cercone E, RookK, Sohel BM, et al. Impact of intensive handwashing promotion on household transmission of influenza in a low income setting: preliminary results of a randomized controlled clinical trial. American Journal of Tropical Medicine and Hygiene2011;85(6):381.
23. FarrBM, HendleyJO, KaiserDL, GwaltneyJM. Two randomised controlled trials of virucidal nasal tissues in the prevention of natural upper respiratory infections. American Journal of Epidemiology1988;128:1162-72. 10.1093/oxfordjournals.aje.a1150593055950 doi:10.1093/oxfordjournals.aje.a115059 PubMed
24. FarrBM, HendleyJO, KaiserDL, GwaltneyJM. Two randomised controlled trials of virucidal nasal tissues in the prevention of natural upper respiratory infection. American Journal of Epidemiology1988;128:1162-72. 10.1093/oxfordjournals.aje.a1150593055950 doi:10.1093/oxfordjournals.aje.a115059 PubMed
25. FeldmanL, GaliliE, CohenY, HartalM, YavnaiN, NetzerI. Routine chlorhexidine gluconate use onboard navy surface vessels to reduce infection: a cluster randomized controlled trial. American Journal of Infection Control2016;44(12):1535-8. 10.1016/j.ajic.2016.04.23327350113 doi:10.1016/j.ajic.2016.04.233 PubMed
26. FretheimA, ElgersmaIH, HelleveA, ElstrømP, KacelnikO, HemkensLG. Glasses against transmission of 1 SARS-CoV-2 in the community (GLASSY): a pragmatic randomized trial. medRxiv preprint doi: https://doi.org/10.1101/2022.07.31.22278223 accessed 20 September 2022.
27. GoodallEC, GranadosAC, LuinstraK, PullenayegumE, ColemanBL, LoebM, et al. Vitamin D3 and gargling for the prevention of upper respiratory tract infections: a randomized controlled trial. BMC Infectious Diseases2014;14:273. 10.1186/1471-2334-14-273PMC404135824885201 doi:10.1186/1471-2334-14-273 PubMed
28. Gutiérrez-GarcíaR, De La Cerda-ÁngelesJC, Cabrera-LiconaA, Delgado-EncisoI, Mervitch-SigalN, Paz-MichelBA. Nasopharyngeal and oropharyngeal rinses with neutral electrolyzed water prevents COVID-19 in front-line health professionals: a randomized, open-label, controlled trial in a general hospital in Mexico City. Biomedical Reports2021;16(2):11. [DOI: 10.3892/br.2021.1494]PMC871932534987795 doi:10.3892/br.2021.1494 PubMed
29. Gwaltney JM Jr, MoskalskiPB, HendleyJO. Interruption of experimental rhinovirus transmission. Journal of Infectious Diseases1980;142(6):811-5. 10.1093/infdis/142.6.8116257799 doi:10.1093/infdis/142.6.811 PubMed
30. HartingerSM, LanataCF, HattendorfJ, VerasteguiH, GilAI, WolfJ, et al. Improving household air, drinking water and hygiene in rural Peru: a community-randomized controlled trial of an integrated environmental home-based intervention package to improve child health. International Journal of Epidemiology2016;45(6):2089-99. 10.1093/ije/dyw242PMC584183927818376 doi:10.1093/ije/dyw242 PubMed
31. HelsingenLM, LøbergM, RefsumE, GjøsteinDK, WieszczyP, Olsvik Ø, et al, for the TRAiN study group. Covid-19 transmission in fitness centers in Norway - a randomized trial. BMC Public Health2021;21(1):2103. [DOI: 10.1186/s12889 - 021 - 12073 - 0]10.1186/s12889-021-12073-0PMC859595934789188 doi:10.1186/s12889-021-12073-0 PubMed
32. HubnerNO, HubnerC, WodnyM, KampfG, KramerA. Effectiveness of alcohol-based hand disinfectants in a public administration: impact on health and work performance related to acute respiratory symptoms and diarrhoea. BMC Infectious Diseases2010;10(250):1-8. 10.1186/1471-2334-10-250PMC293963820735818 doi:10.1186/1471-2334-10-250 PubMed
33. HudaTM, UnicombL, JohnstonRB, HalderAK, Yushuf SharkerMA, LubySP. Interim evaluation of a large scale sanitation, hygiene and water improvement programme on childhood diarrhea and respiratory disease in rural Bangladesh. Social Science & Medicine2012;75(4):604-11. 10.1016/j.socscimed.2011.10.04222197292 doi:10.1016/j.socscimed.2011.10.042 PubMed
34. IbfeltT, EngelundEH, SchultzAC, AndersenLP. Effect of cleaning and disinfection of toys on infectious diseases and micro-organisms in daycare nurseries. Journal of Hospital Infection2015;89(2):109-15. 10.1016/j.jhin.2014.10.007PMC711457125549827 doi:10.1016/j.jhin.2014.10.007 PubMed
35. IdeK, YamadaH, MatsushitaK, ItoM, NojiriK, ToyoizumiK, et al. Effects of green tea gargling on the prevention of influenza infection in high school students: a randomized controlled study. PLOS One2014;9(5):e96373. 10.1371/journal.pone.0096373PMC402399624836780 doi:10.1371/journal.pone.0096373 PubMed
36. Ide K, Yamada H, TakumaN, KawasakiY, Morohoshi H, TakenakaA, et al. Effects of catechin-treated masks on the prevention of influenza infection: an exploratory randomized study. Japanese Journal of Clinical Pharmacology and Therapeutics2016;47(6):229-34.
37. JacobsJL, OhdeS, TakahashiO, TokudaY, OmataF, FukuiT. Use of surgical face masks to reduce the incidence of the common cold among health care workers in Japan: a randomized controlled trial. American Journal of Infection Control2009;37(5):417-9. 10.1016/j.ajic.2008.11.00219216002 doi:10.1016/j.ajic.2008.11.002 PubMed
38. KotchJB, WeigleKA, WeberDJ, CliffordRM, HarmsTO, LodaFA, et al. Evaluation of an hygienic intervention in child day-care centers. Pediatrics1994;94(6 Pt 2):991-4. 7971087 PubMed
39. LadegaardMB, StageV. Hand hygiene and sickness among small children attending day care centres. An interventional study. Ukesgrift von Laeger1999;161:4396-400. 10487104 PubMed
40. LarsonEL, FerngY, Wong-McLoughlinJ, WangS, HaberM, MorseSS. Impact of non-pharmaceutical interventions on URIs and influenza in crowded, urban households. Public Health Reports2010;125(2):178-91. 10.1177/003335491012500206PMC282184520297744 doi:10.1177/003335491012500206 PubMed
41. LittleP, StuartB, HobbsFD, MooreM, BarnettJ, Popoola D, et al. An internet-delivered handwashing intervention to modify influenza-like illness and respiratory infection transmission (PRIMIT): a primary care randomised trial. Lancet2015;386:1631–9. 10.1016/S0140-6736(15)60127-126256072 doi:10.1016/S0140-6736(15)60127-1 PubMed
42. LoebM, DafoeN, MahonyJ, JohnM, SarabiaA, GlavinV, et al. Surgical mask vs N95 respirator for preventing influenza among health care workers: a randomized trial. JAMA2009;302(17):1865-71. 10.1001/jama.2009.146619797474 doi:10.1001/jama.2009.1466 PubMed
43. Longini IM Jr, MontoAS. Efficacy of virucidal nasal tissues in interrupting familial transmission of respiratory agents. A field trial in Tecumseh, Michigan. American Journal of Epidemiology1988;128(3):639-44. 10.1093/oxfordjournals.aje.a1150112843040 doi:10.1093/oxfordjournals.aje.a115011 PubMed
44. LubySP, AgboatwallaM, FeikinDR, PainterJ, BillhimerW, AltafA, et al. Effect of handwashing on child health: a randomised controlled trial. Lancet2005;366(9481):225-33. 10.1016/S0140-6736(05)66912-716023513 doi:10.1016/S0140-6736(05)66912-7 PubMed
45. MacIntyreCR, CauchemezS, DwyerDE, SealeH, CheungP, BrowneG, et al. Face mask use and control of respiratory virus transmission in households. Emerging Infectious Diseases2009;15(2):233-41. 10.3201/eid1502.081167PMC266265719193267 doi:10.3201/eid1502.081167 PubMed
46. MacIntyreCR, WangQ, Cauchemez S, Seale H, DwyerDE, YangP, et al. A cluster randomized clinical trial comparing fit-tested and non-fit-tested N95 respirators to medical masks to prevent respiratory virus infection in health care workers. Influenza and Other Respiratory Viruses2011;5(3):170–9. 10.1111/j.1750-2659.2011.00198.xPMC494158721477136 doi:10.1111/j.1750-2659.2011.00198.x PubMed
47. MacIntyreCR, WangQ, RahmanB, SealeH, RiddaI, GaoZ, et al. Efficacy of face masks and respirators in preventing upper respiratory tract bacterial colonization and co-infection in hospital healthcare workers. Preventive Medicine2014;62:1-7. 10.1016/j.ypmed.2014.01.015PMC717220524472436 doi:10.1016/j.ypmed.2014.01.015 PubMed
48. MacIntyreCR, WangQ, SealeH, YangP, ShiW, GaoZ, et al. A randomized clinical trial of three options for N95 respirators and medical masks in health workers. American Journal of Respiratory and Critical Care Medicine2013;187(9):960-6. [DOI: 10.1164/rccm.201207-1164OC]23413265 doi:10.1164/rccm.201207-1164OC PubMed
49. MacIntyreCR, SealeH, DungTC, HienNT, NgaPT, ChughtaiAA, et al. A cluster randomised trial of cloth masks compared with medical masks in healthcare workers. BMJ Open2015;5(4):e006577. 10.1136/bmjopen-2014-006577PMC442097125903751 doi:10.1136/bmjopen-2014-006577 PubMed
50. MacIntyreCR, ZhangY, ChughtaiAA, SealeH, ZhangD, ChuY, et al. Cluster randomised controlled trial to examine medical mask use as source control for people with respiratory illness. BMJ Open2016;6(12):e012330. [DOI: 10.1136/bmjopen-2016-012330]PMC522371528039289 doi:10.1136/bmjopen-2016-012330 PubMed
51. McConeghyKW, BaierR, McGrathKP, BaerCJ, MorV. Implementing a pilot trial of an infection control program in nursing homes: results of a matched cluster randomized trial. Journal of the American Medical Directors Association2017;18(8):707-12. 10.1016/j.jamda.2017.03.00328465127 doi:10.1016/j.jamda.2017.03.003 PubMed
52. MillarEV, SchlettCD, LawNN, ChenWJ, D'OnofrioMJ, BennettJW, et al. Reduction in acute respiratory infection among military trainees: secondary effects of a hygiene-based cluster-randomized trial for skin and soft-tissue infection prevention. Infection Control and Hospital Epidemiology2016;37(9):1118-20. 10.1017/ice.2016.154PMC582816127387422 doi:10.1017/ice.2016.154 PubMed
53. MiyakiK, SakurazawaH, MikurubeH, NishizakaM, AndoH, SongY, et al. An effective quarantine measure reduced the total incidence of influenza A H1N1 in the workplace: another way to control the H1N1 flu pandemic. Journal of Occupational Health2011;53(4):287-92. [DOI: 10.1539/joh.10-0024-fs]21597235 doi:10.1539/joh.10-0024-fs PubMed
54. MortonJL, SchultzAA. Healthy hands: use of alcohol gel as an adjunct to handwashing in elementary school children. Journal of School Nursing2004;20(3):161-7. 10.1177/1059840504020003060115147226 doi:10.1177/10598405040200030601 PubMed
55. Najnin N, Leder K, ForbesA, Unicomb L, WinchPJ, RamPK, et al. Impact of a large-scale handwashing intervention on reported respiratory illness: findings from a cluster-randomized controlled trial. American Journal of Tropical Medicine and Hygiene2019;100(3):742-9. 10.4269/ajtmh.18-0644PMC640293230608050 doi:10.4269/ajtmh.18-0644 PubMed
56. NicholsonJA, NaeeniM, HoptroffM, MathesonJR, RobertsAJ, TaylorD, et al. An investigation of the effects of a hand washing intervention on health outcomes and school absence using a randomised trial in Indian urban communities. Tropical Medicine and International Health2014;19(3):284-92. [DOI: 10.1111/tmi.12254]24382344 doi:10.1111/tmi.12254 PubMed
57. Pandejpong D, Danchaivijitr S, Vanprapa N, Pandejpong T, CookEF. Appropriate time-interval application of alcohol hand gel on reducing influenza-like illness among preschool children: a randomized, controlled trial. American Journal of Infection Control2012;40(6):507-11. [DOI: 10.1016/j.ajic.2011.08.020]PMC711531922264742 doi:10.1016/j.ajic.2011.08.020 PubMed
58. PriestP, McKenzieJE, Audas R, Poore M, Brunton C, ReevesL. Hand sanitiser provision for reducing illness absences in primary school children: a cluster randomised trial. PLOS Medicine2014;11(8):e1001700. 10.1371/journal.pmed.1001700PMC413049225117155 doi:10.1371/journal.pmed.1001700 PubMed
59. Radonovich LJ Jr, SimberkoffMS, BessesenMT, BrownAC, CummingsDA, GaydosCA, et al, ResPECT investigators. N95 respirators vs medical masks for preventing influenza among health care personnel: a randomized clinical trial. JAMA2019;322(9):824-33. 10.1001/jama.2019.11645PMC672416931479137 doi:10.1001/jama.2019.11645 PubMed
60. RamPK, DiVitaMA, Khatun-e-JannatK, IslamM, Krytus K, Cercone E, et al. Impact of intensive handwashing promotion on secondary household influenza-like illness in rural Bangladesh: findings from a randomized controlled trial. PLOS One2015;10(6):e0125200. [DOI: 10.1371/journal.pone.0125200]PMC446583926066651 doi:10.1371/journal.pone.0125200 PubMed
61. RobertsL, SmithW, JormL, PatelM, DouglasRM, McGilchristC. Effect of infection control measures on the frequency of upper respiratory infection in child care: a randomised controlled study. Pediatrics2000;105:738-42. 10.1542/peds.105.4.73810742313 doi:10.1542/peds.105.4.738 PubMed
62. SandoraTJ, TaverasEM, ShihMC, ResnickEA, LeeGM, Ross-DegnanD, et al. A randomized, controlled trial of a multifaceted intervention including alcohol-based hand sanitizer and hand-hygiene education to reduce illness transmission in the home. Pediatrics2005;116(3):587-94. 10.1542/peds.2005-019916140697 doi:10.1542/peds.2005-0199 PubMed
63. SandoraTJ, ShihMC, GoldmannDA. Reducing absenteeism from gastrointestinal and respiratory illness in elementary school students: a randomized, controlled trial of an infection-control intervention. Pediatrics2008;121(6):e1555-62. 10.1542/peds.2007-259718519460 doi:10.1542/peds.2007-2597 PubMed
64. KitamuraT, SatomuraK, KawamuraT, YamadaS, TakashimaK, SuganumaN, et al. Can we prevent influenza-like illnesses by gargling?Internal Medicine2007;46(18):1623-4. 10.2169/internalmedicine.46.010417878657 doi:10.2169/internalmedicine.46.0104 PubMed
65. SatomuraK, KitamuraT, KawamuraT, ShimboT, WatanabeM, KameiM, et al. Prevention of upper respiratory tract infections by gargling: a randomized trial. American Journal of Preventive Medicine2005;29(4):302-7. 10.1016/j.amepre.2005.06.01316242593 doi:10.1016/j.amepre.2005.06.013 PubMed
66. Savolainen-KopraC, HaapakoskiJ, PeltolaPA, ZieglerT, KorpelaT, AnttilaP, et al. Hand washing with soap and water together with behavioural recommendations prevents infections in common work environment: an open cluster-randomized trial. Trials2012;13:10. [DOI: 10.1186/1745-6215-13-10]PMC329660422243622 doi:10.1186/1745-6215-13-10 PubMed
67. SimmermanJM, SuntarattiwongP, LevyJ, JarmanRG, KaewchanaS, GibbonsRV, et al. Findings from a household randomized controlled trial of hand washing and face masks to reduce influenza transmission in Bangkok, Thailand. Influenza and Other Respiratory Viruses2011;5(4):256-67. [DOI: 10.1111/j.1750-2659.2011.00205.x]PMC463454521651736 doi:10.1111/j.1750-2659.2011.00205.x PubMed
68. StebbinsS, CummingsDA, StarkJH, VukotichC, MitrukaK, ThompsonW, et al. Reduction in the incidence of influenza A but not influenza B associated with use of hand sanitizer and cough hygiene in schools: a randomized controlled trial. Pediatric Infectious Disease Journal2011;30(11):921-6. [DOI: 10.1097/INF.0b013e3182218656]PMC347086821691245 doi:10.1097/INF.0b013e3182218656 PubMed
69. SuessT, RemschmidtC, SchinkSB, SchweigerB, NitscheA, SchroederK, et al. The role of facemasks and hand hygiene in the prevention of influenza transmission in households: results from a cluster randomised trial; Berlin, Germany, 2009-2011. BMC Infectious Disease2012;12:26. [DOI: 10.1186/1471-2334-12-26]PMC328507822280120 doi:10.1186/1471-2334-12-26 PubMed
70. SwarthoutJ, RamPK, ArnoldCD, DentzHN, ArnoldBF, KalunguS, et al. Effects of individual and combined water, sanitation, handwashing, and nutritional interventions on child respiratory infections in rural Kenya: a cluster-randomized controlled trial. American Journal of Tropical Medicine and Hygiene2020;102(6):1286-95. [DOI: 10.4269/ajtmh.19-0779]PMC725313832228789 doi:10.4269/ajtmh.19-0779 PubMed
71. TalaatM, AfifiS, DuegerE, El-AshryN, MarfinA, KandeelA, et al. Effects of hand hygiene campaigns on incidence of laboratory-confirmed influenza and absenteeism in schoolchildren, Cairo, Egypt. Emerging Infectious Diseases2011;17(4):619-25. [DOI: 10.3201/eid1704.101353]PMC337741221470450 doi:10.3201/eid1704.101353 PubMed
72. TeesingGR, RichardusJH, NieboerD, PetrignaniM, ErasmusV, Verduijn-LeenmanA, et al. The effect of a hand hygiene intervention on infections in residents of nursing homes: a cluster randomized controlled trial. Antimicrobial Resistance & Infection Control2021;10(1):80. [DOI: 10.1186/s13756-021-00946-3.]PMC813899034016156 doi:10.1186/s13756-021-00946-3. PubMed
73. TemimeL, CohenN, Ait-BouziadK, DenormandieP, DabW, HocineMN. Impact of a multicomponent hand hygiene-related intervention on the infectious risk in nursing homes: a cluster randomized trial. American Journal of Infection Control2018;46(2):173-9. [DOI: 10.1016/j.ajic.2017.08.030]28987524 doi:10.1016/j.ajic.2017.08.030 PubMed
74. TurnerRB, BiedermannKA, MorganJM, KeswickB, ErtelKD, BarkerMF. Efficacy of organic acids in hand cleansers for prevention of rhinovirus infections. Antimicrobial Agents and Chemotherapy2004;48(7):2595-8. 10.1128/AAC.48.7.2595-2598.2004PMC43419015215114 doi:10.1128/AAC.48.7.2595-2598.2004 PubMed
75. TurnerRB, BiedermannKA, MorganJM, KeswickB, ErtelKD, BarkerMF. Efficacy of organic acids in hand cleansers for prevention of rhinovirus infections. Antimicrobial Agents and Chemotherapy2004;48(7):2595-8. 10.1128/AAC.48.7.2595-2598.2004PMC43419015215114 doi:10.1128/AAC.48.7.2595-2598.2004 PubMed
76. TurnerRB, FulsJL, RodgersND, GoldfarbHB, LockhartLK, AustLB. A randomized trial of the efficacy of hand disinfection for prevention of rhinovirus infection. Clinical Infectious Diseases2012;54(10):1422-6. [DOI: 10.1093/cid/cis201]22412063 doi:10.1093/cid/cis201 PubMed
77. WhiteCG, ShinderFS, ShinderAL, DyerDL. Reduction of illness absenteeism in elementary schools using an alcohol-free instant hand sanitizer. Journal of School Nursing2001;17(5):258-65. 11885342 PubMed
78. YeungWK, TamWS, WongTW. Cluster randomized controlled trial of a hand hygiene intervention involving pocket-sized containers of alcohol-based hand rub for the control of infections in long-term care facilities. Infection Control and Hospital Epidemiology2011;32:67-76. 10.1086/65763621087125 doi:10.1086/657636 PubMed
79. YoungBC, EyreDW, KendrickS, WhiteC, SmithS, BeveridgeG, et al. Daily testing for contacts of individuals with SARS-CoV-2 infection and attendance and SARS-CoV-2 transmission in English secondary schools and colleges: an open-label, cluster-randomised trial. Lancet2021;398:1217-29. [DOI: .1016/S0140 - 6736(21)01908 - 5]10.1016/S0140-6736(21)01908-5PMC843962034534517 doi:10.1016/S0140-6736(21)01908-5 PubMed
80. ZomerTP, ErasmusV, LoomanCW, Tjon-A-TsienA, Van BeeckEF, De GraafJM, et al. A hand hygiene intervention to reduce infections in child daycare: a randomized controlled trial. Epidemiology and Infection2015;143(12):2494-502. [DOI: 10.1017/S095026881400329X]PMC453147625566827 doi:10.1017/S095026881400329X PubMed
81. Abou El HassanMA, Meulen-MuilemanIvan der, AbbasS, KruytFA. Conditionally replicating adenoviruses kill tumor cells via a basic apoptotic machinery-independent mechanism that resembles necrosis-like programmed cell death. Journal of Virology2004;78(22):12243-51. 10.1128/JVI.78.22.12243-12251.2004PMC52507715507611 doi:10.1128/JVI.78.22.12243-12251.2004 PubMed
82. AhmadianM, GhasemiM, Nasrollahi BorujeniN, AfshanS, FallahM, AyasehH, et al. Does wearing a mask while exercising amid COVID-19 pandemic affect hemodynamic and hematologic function among healthy individuals? Implications of mask modality, sex, and exercise intensity. Physician and Sportsmedicine2022;50(3):257-68. 10.1080/00913847.2021.192294733902400 doi:10.1080/00913847.2021.1922947 PubMed
83. AmiravI, OronA, TalG, CesarK, BallinA, HouriS, et al. Aerosol delivery in respiratory syncytial virus bronchiolitis: hood or face mask?Journal of Pediatrics2005;147(5):627-31. 10.1016/j.jpeds.2005.05.03516291353 doi:10.1016/j.jpeds.2005.05.035 PubMed
84. AndersonRM, FraserC, GhaniAC, DonnellyCA, RileyS, FergusonNM, et al. Epidemiology, transmission dynamics and control of SARS: the 2002-2003 epidemic. Philosophical Transactions of the Royal Society of London - Series B: Biological Sciences2004;359(1447):1091-105. 10.1098/rstb.2004.1490PMC169338915306395 doi:10.1098/rstb.2004.1490 PubMed
85. Anon. Antiseptic skin cleansers may prevent rhinovirus transmission. Clinical Infectious Diseases2002;34(3):ii.
86. Anon. Can antiviral tissues prevent the spread of colds?Consumer Reports2004;69(12):56. 15586956 PubMed
87. Anon. Antiviral Kleenex. Medical Letter on Drugs & Therapeutics2005;47(1199):3-4. 15599337 PubMed
88. Anon. Focusing on this year's flu...use healthy handwashing...and when soap and water aren't handy, hand gels work well, too. Child Health Alert2005;23:1-2. 16416537 PubMed
89. How long is a cold contagious? Is there any way to prevent transmitting a cold?Johns Hopkins Medical Letter, Health After 502005;17(10):8. 16437750 PubMed
90. ApisarnthanarakA, ApisarnthanarakP, CheevakumjornB, MundyLM. Intervention with an infection control bundle to reduce transmission of influenza-like illnesses in a Thai preschool. Infection Control and Hospital Epidemiology2009;30(9):817-22. 10.1086/59977319614542 doi:10.1086/599773 PubMed
91. ApisarnthanarakA, UyekiTM, PuthavathanaP, KitphatiR, MundyLM. Reduction of seasonal influenza transmission among healthcare workers in an intensive care unit: a 4-year intervention study in Thailand. Infection Control and Hospital Epidemiology2010;31(10):996-1003. 10.1086/65656520807075 doi:10.1086/656565 PubMed
92. AragonD, SoleML, BrownS. Outcomes of an infection prevention project focusing on hand hygiene and isolation practices. AACN Clinical Issues2005;16(2):121-3. 10.1097/00044067-200504000-0000215876879 doi:10.1097/00044067-200504000-00002 PubMed
93. Azor-MartinezE, Gonzalez-JimenezY, Seijas-VazquezML, Cobos-CarrascosaE, Santisteban-MartinezJ, Martinez-LopezJM, et al. The impact of common infections on school absenteeism during an academic year. American Journal of Infection Control2014;42(6):632-7. 10.1016/j.ajic.2014.02.01724837113 doi:10.1016/j.ajic.2014.02.017 PubMed
94. BarrosAJ, RossDA, FonsecaWV, WilliamsLA, Moreira-FilhoDC. Preventing acute respiratory infections and diarrhoea in child care centres. Acta Paediatrica1999;88(10):1113-8. 10.1080/0803525995016818010565459 doi:10.1080/08035259950168180 PubMed
95. BauerG, BossiL, SantoallaM, RodríguezS, FariñaD, SperanzaAM. Impacto de un programa de prevención de infecciones respiratorias en lactantes prematuros de alto riesgo: estudio prospectivo y multicéntrico. Archivos Argentinos de Pediatria2009;107(2):111-8. 10.1590/S0325-0075200900020000419452082 doi:10.1590/S0325-00752009000200004 PubMed
96. BellDM. World Health Organization Working Group on International and Community Transmission of SARS. Emerging Infectious Diseases2004;10(11):1900-6. 10.3201/eid1011.040729PMC332904515550198 doi:10.3201/eid1011.040729 PubMed
97. Bellissimo-RodriguesF, Bellissimo-RodriguesWT, VianaJM, TeixeiraGC, NicoliniE, Auxiliadora-MartinsM, et al. Effectiveness of oral rinse with chlorhexidine in preventing nosocomial respiratory tract infections among intensive care unit patients. Infection Control and Hospital Epidemiology2009;30(10):952-8. 10.1086/60572219743899 doi:10.1086/605722 PubMed
98. Ben-AbrahamR, KellerN, SzoldO, VardiA, WeinbergM, BarzilayZ, et al. Do isolation rooms reduce the rate of nosocomial infections in the pediatric intensive care unit?Journal of Critical Care2002;17(3):176-80. 10.1053/jcrc.2002.3580912297993 doi:10.1053/jcrc.2002.35809 PubMed
99. BlackRE, DykesAC, AndersonKE, WellsJG, SinclairSP, GaryGW, et al. Handwashing to prevent diarrhea in day-care centers. American Journal of Epidemiology1981;113(4):445-51. 10.1093/oxfordjournals.aje.a1131127211827 doi:10.1093/oxfordjournals.aje.a113112 PubMed
100. BorkowG, ZhouSS, PageT, GabbayJ. A novel anti-influenza copper oxide containing respiratory face mask. PLOS One2010;5(6):1-8. 10.1371/journal.pone.0011295PMC289246420592763 doi:10.1371/journal.pone.0011295 PubMed
101. BouadmaL, MourvillierB, DeilerV, Le CorreB, LolomI, RégnierB, et al. A multifaceted program to prevent ventilator-associated pneumonia: impact on compliance with preventive measures. Critical Care Medicine2010;38(3):789-96. 10.1097/CCM.0b013e3181ce21af20068461 doi:10.1097/CCM.0b013e3181ce21af PubMed
102. BowenA, MaH, OuJ, BillhimerW, LongT, MintzE, et al. A cluster-randomized controlled trial evaluating the effect of a handwashing-promotion program in Chinese primary schools. American Journal of Tropical Medicine and Hygiene2007;76(6):1166-73. 17556631 PubMed
103. BreugelmansJG, ZucsP, PortenK, BrollS, NiedrigM, AmmonA, et al. SARS transmission and commercial aircraft. Emerging Infectious Diseases2004;10(8):1502-3. 10.3201/eid1008.040093PMC332040015503396 doi:10.3201/eid1008.040093 PubMed
104. CaiW, SchweigerB, BuchholzU, BudaS, LittmannM, HeuslerJ, et al. Protective measures and H5N1-seroprevalence among personnel tasked with bird collection during an outbreak of avian influenza A/H5N1 in wild birds, Ruegen, Germany, 2006. BMC Infectious Diseases2009;9:170. 10.1186/1471-2334-9-170PMC276735219835632 doi:10.1186/1471-2334-9-170 PubMed
105. CantagalliMR, AlvimVF, AndradeEC, LeiteIC. Associação entre desnutrição energético-protéica e infecção respiratória aguda em crianças na atenção primária à saúde. Revista de APS2010;13(1):26-33.
106. Carbonell-EstranyX, BontL, DoeringG, GouyonJB, LanariM. Clinical relevance of prevention of respiratory syncytial virus lower respiratory tract infection in preterm infants born between 33 and 35 weeks gestational age. European Journal of Clinical Microbiology and Infectious Diseases2008;27(10):891-9. 10.1007/s10096-008-0520-818629558 doi:10.1007/s10096-008-0520-8 PubMed
107. CarterJM. Hand washing decreases risk of colds and flu. Journal of the National Medical Association2002;94(2):A11. PMC259411711853053 PubMed
108. Castillo-ChavezC, Castillo-GarsowCW, YakubuAA. Mathematical models of isolation and quarantine. JAMA2003;290(21):2876-7. 10.1001/jama.290.21.287614657077 doi:10.1001/jama.290.21.2876 PubMed
109. CavaMA, FayKE, BeanlandsHJ, McCayEA, WignallR. Risk perception and compliance with quarantine during the SARS outbreak. Journal of Nursing Scholarship2005;37(4):343-7. 10.1111/j.1547-5069.2005.00059.x16396407 doi:10.1111/j.1547-5069.2005.00059.x PubMed
110. CavaMA, FayKE, BeanlandsHJ, McCayEA, WignallR. The experience of quarantine for individuals affected by SARS in Toronto. Public Health Nursing2005;22(5):398-406. 10.1111/j.0737-1209.2005.220504.x16229732 doi:10.1111/j.0737-1209.2005.220504.x PubMed
111. Centers for Disease Control and Prevention. Cluster of severe acute respiratory syndrome cases among protected health-care workers - Toronto, Canada, April 2003. Morbidity & Mortality Weekly Report2003;52(19):433-6. 12807083 PubMed
112. Centers for Disease Control and Prevention. Use of quarantine to prevent transmission of severe acute respiratory syndrome - Taiwan, 2003. Morbidity & Mortality Weekly Report2003;52(29):680-3. 12881699 PubMed
113. ChaiLY, NgTM, HabibAG, SinghK, KumarasingheG, TambyahPA. Paradoxical increase in methicillin-resistant Staphylococcus aureus acquisition rates despite barrier precautions and increased hand washing compliance during an outbreak of severe acute respiratory syndrome. Clinical Infectious Diseases2005;40(4):623-3. 10.1086/427150PMC710785015712092 doi:10.1086/427150 PubMed
114. ChamiK, GavazziG, Bar-HenA, CarratF, WazièresBde, LejeuneB, et al. A short-term, multicomponent infection control program in nursing homes: a cluster randomized controlled trial. Journal of the American Medical Directors Association2012;13(6):569.e9-569.e17. 10.1016/j.jamda.2012.04.00822682697 doi:10.1016/j.jamda.2012.04.008 PubMed
115. ChaovavanichA, WongsawatJ, DowellSF, InthongY, SangsajjaC, SanguanwongseN, et al. Early containment of severe acute respiratory syndrome (SARS); experience from Bamrasnaradura Institute, Thailand. Journal of the Medical Association of Thailand2004;87(10):1182-7. 15560695 PubMed
116. ChauPH, YipPS. Monitoring the severe acute respiratory syndrome epidemic and assessing effectiveness of interventions in Hong Kong Special Administrative Region. Journal of Epidemiology and Community Health2003;57(10):766-9. 10.1136/jech.57.10.766PMC173229114573569 doi:10.1136/jech.57.10.766 PubMed
117. ChauJP, ThompsonDR, TwinnS, LeeDT, LopezV, HoLS. An evaluation of SARS and droplet infection control practices in acute and rehabilitation hospitals in Hong Kong. Hong Kong Medical Journal2008;14(Suppl 4):44-7. 18708675 PubMed
118. ChenYC, ChiangLC. Effectiveness of hand-washing teaching programs for families of children in paediatric intensive care units. Journal of Clinical Nursing2007;16(6):1173-9. 10.1111/j.1365-2702.2007.01665.x17518892 doi:10.1111/j.1365-2702.2007.01665.x PubMed
119. ChenMH, ChangPC. The effectiveness of mouthwash against SARS-CoV-2 infection: A review of scientific and clinical evidence. Journal of the Formosan Medical Association2022;121(5):879-85. [10.1016/j.jfma.2021.10.001]10.1016/j.jfma.2021.10.001PMC849874534666923 doi:10.1016/j.jfma.2021.10.001 PubMed
120. ChengVC, TaiJW, WongLM, ChanJF, LiIW, ToKK, et al. Prevention of nosocomial transmission of swine-origin pandemic influenza virus A/H1N1 by infection control bundle. Journal of Hospital Infection2010;74(3):271-7. 10.1016/j.jhin.2009.09.009PMC711883820061056 doi:10.1016/j.jhin.2009.09.009 PubMed
121. ChiaSE, KohD, FonesC, QianF, NgV, TanBH, et al. Appropriate use of personal protective equipment among healthcare workers in public sector hospitals and primary healthcare polyclinics during the SARS outbreak in Singapore. Occupational and Environmental Medicine2005;62(7):473-7. 10.1136/oem.2004.015024PMC174105715961624 doi:10.1136/oem.2004.015024 PubMed
122. ClynesN. Surgical masks vs N95 respirators for preventing influenza. JAMA2010;303(10):937-9. 10.1001/jama.2010.19420215601 doi:10.1001/jama.2010.194 PubMed
123. CostaDD, BritesC, Nunes VazS, Souzade SantanaD, Nunesdos SantosJ, Ramos CuryP. Chlorhexidine mouthwash reduces the salivary viral load of SARS-CoV-2: a randomized clinical trial. Oral Diseases2021;00:1-9. [DOI: 10.1111/odi.14086]34837305 doi:10.1111/odi.14086 PubMed
124. CowlingBJ, MullerMP, WongIO, HoLM, LouieM, McGeerA, et al. Alternative methods of estimating an incubation distribution: examples from severe acute respiratory syndrome. Epidemiology2007;18(2):253-9. 10.1097/01.ede.0000254660.07942.fb17235210 doi:10.1097/01.ede.0000254660.07942.fb PubMed
125. Cyril VitugL, SantiaguelJ, ExcondeMA, BautistaMA. Oral gargle of ethanol-based mouthwash solution and its effects on adult patients with mild COVID-19 infection: an open-label randomized controlled trial. Chest2021;160(4):A2504. [DOI: 10.1016/j.chest.2021.08.014] doi:10.1016/j.chest.2021.08.014
126. DalakotiM, LongC, BainsA, DjohanA, AhmadI, ChanSP, et al. Effect of surgical mask use on peak physical performance during exercise treadmill testing - a real world, crossover study. Frontiers in Physiology2022;13:913974. [DOI: 10.3389/fphys.2022.913974]PMC917102235685282 doi:10.3389/fphys.2022.913974 PubMed
127. DanielsTL, TalbotTR. Unmasking the confusion of respiratory protection to prevent influenza-like illness in crowded community settings. Journal of Infectious Diseases2010;201(4):483-5. 10.1086/65039520088689 doi:10.1086/650395 PubMed
128. DaughertyEL. Health care worker protection in mass casualty respiratory failure: infection control, decontamination, and personal protective equipment. Respiratory Care2008;53(2):201-12; discussion 212-4. 18218151 PubMed
129. DaviesKJ, HerbertAM, WestmorelandD, BaggJ. Seroepidemiological study of respiratory virus infections among dental surgeons. British Dental Journal1994;176(7):262-5. 10.1038/sj.bdj.48084308186035 doi:10.1038/sj.bdj.4808430 PubMed
130. DayRA, St ArnaudS, MonsmaM. Effectiveness of a handwashing program. Clinical Nursing Research1993;2(1):24-40. 10.1177/1054773893002001048453386 doi:10.1177/105477389300200104 PubMed
131. DayT, ParkA, MadrasN, GumelA, WuJ. When is quarantine a useful control strategy for emerging infectious diseases?American Journal of Epidemiology2006;163(5):479-85. 10.1093/aje/kwj056PMC710963816421244 doi:10.1093/aje/kwj056 PubMed
132. Dell'OmodarmeM, PratiMC. The probability of failing in detecting an infectious disease at entry points into a country. Statistics in Medicine2005;24(17):2669-79. 10.1002/sim.2131PMC716960215977301 doi:10.1002/sim.2131 PubMed
133. DenbakAM, AndersenA, BonnesenCT, LaursenB, ErsbøllAK, DueP, et al. Effect evaluation of a randomized trial to reduce infectious illness and illness-related absenteeism among schoolchildren: The Hi Five Study. Pediatric Infectious Disease Journal2018;37(1):16-21. 10.1097/INF.000000000000168628746262 doi:10.1097/INF.0000000000001686 PubMed
134. DesenclosJC, WerfSvan der, BonmarinI, Levy-BruhlD, YazdanpanahY, HoenB, et al. Introduction of SARS in France, March-April, 2003. Emerging Infectious Diseases2004;10(2):195-200. 10.3201/eid1002.030351PMC332292015030682 doi:10.3201/eid1002.030351 PubMed
135. DiGiovanniC, ConleyJ, ChiuD, ZaborskiJ. Factors influencing compliance with quarantine in Toronto during the 2003 SARS outbreak. Biosecurity and Bioterrorism2004;2(4):265-72. 10.1089/bsp.2004.2.26515650436 doi:10.1089/bsp.2004.2.265 PubMed
136. DoebbelingBN, StanleyGL, SheetzCT. Comparative efficacy of alternative hand-washing agents in reducing nosocomial infections in intensive care units. New England Journal of Medicine1992;327(2):88-92. 10.1056/NEJM1992070932702051285746 doi:10.1056/NEJM199207093270205 PubMed
137. DwoshHA, HongHH, AustgardenD, HermanS, SchabasR. Identification and containment of an outbreak of SARS in a community hospital. Canadian Medical Association Journal2003;168(11):1415-20. PMC15595712771070 PubMed
138. EdmondsS, DzyakanavaV, MacingaD. Efficacy of hand hygiene products against pandemic H1N1 influenza. American Journal of Infection Control2010;38(5):E132-3.
139. EggerF, BlumenauerD, FischerP, VenhorstA, KulenthiranS, BewarderY, et al. Effects of face masks on performance and cardiorespiratory response in well-trained athletes. Clinical Infectious Diseases2022;111(3):264-71. [DOI: 10.1007/s00392-021-01877-0]PMC817995334091726 doi:10.1007/s00392-021-01877-0 PubMed
140. FendlerEJ, AliY, HammondBS, LyonsMK, KelleyMB, VowellNA. The impact of alcohol hand sanitizer use on infection rates in an extended care facility. American Journal of Infection Control2002;30(4):226-33. 10.1067/mic.2002.12012912032498 doi:10.1067/mic.2002.120129 PubMed
141. FerrerMD, Sánchez BarruecoA, Martinez‑BeneytoY, Mateos-MorenoMV, Ausina-MárquezV, García-VázquezE, et al. Clinical evaluation of antiseptic mouth rinses to reduce salivary load of SARS-CoV-2. Scientific Reports2021;11:24392. [DOI: https://doi.org/10.1038/s41598-021-03461-y]10.1038/s41598-021-03461-yPMC869558234937855 doi:10.1038/s41598-021-03461-y PubMed
142. FlintJ, BurtonS, MaceyJF, DeeksSL, TamTW, KingA, et al. Assessment of in-flight transmission of SARS - results of contact tracing. Canadian Communicable Disease Report2003;29(12):105-10. 12822294 PubMed
143. FungCP, HsiehTL, TanKH, LohCH, WuJS, LiC, et al. Rapid creation of a temporary isolation ward for patients with severe acute respiratory syndrome in Taiwan. Infection Control and Hospital Epidemiology2004;25(12):1026-32. 10.1086/50233915636288 doi:10.1086/502339 PubMed
144. GarciaMC. The protection against influenza provided by surgical masks is not inferior to what the FFP2 (N95) respiratory protector can give. FMC Formacion Medica Continuada en Atencion Primaria2010;17(5):365.
145. GaydosJC. Returning to the past: respiratory illness, vaccines, and handwashing. American Journal of Preventive Medicine2001;21(2):150-1. 10.1016/s0749-3797(01)00332-411457636 doi:10.1016/s0749-3797(01)00332-4 PubMed
146. GensiniGF, YacoubMH, ContiAA. The concept of quarantine in history: from plague to SARS. Journal of Infection2004;49(4):257-61. 10.1016/j.jinf.2004.03.002PMC713362215474622 doi:10.1016/j.jinf.2004.03.002 PubMed
147. GharebaghiN, Valizade HasanloeiMA, Mosarrezaii AgdamA, MohseniradS. The effect of combined mouth wash gentamycine, colistin and vancomycine in prevention of ventilator associated pneumonia in mechanical ventilatory patients admitted to intensive care unit: a randomized clinical trial. Scientific Journal of Kurdistan University of Medical Sciences2020;104:105-16. [DOI: 10.52547/sjku.25.1.105] doi:10.52547/sjku.25.1.105
148. GirouE, LoyeauS, LegrandP, OppeinF, Brun-BuissonC. Efficacy of handrubbing with alcohol based solution versus standard handwashing with antiseptic soap: randomised clinical trial. BMJ2002;325:362. 10.1136/bmj.325.7360.362PMC11788512183307 doi:10.1136/bmj.325.7360.362 PubMed
149. GiulianoKK, PenoyerD, MiddletonA. Oral care as prevention for nonventilator hospital-acquired pneumonia: a four-unit cluster randomized study. American Journal of Nursing2021;121(6):24-33. 10.1097/01.NAJ.0000753468.99321.9333993136 doi:10.1097/01.NAJ.0000753468.99321.93 PubMed
150. GlassK, BeckerNG. Evaluation of measures to reduce international spread of SARS. Epidemiology and Infection2006;134(5):1092-101. 10.1017/S0950268806005863PMC287047516476169 doi:10.1017/S0950268806005863 PubMed
151. GoelS, GuptaAK, SinghA, LenkaSR. Preparations and limitations for prevention of severe acute respiratory syndrome in a tertiary care centre of India. Journal of Hospital Infection2007;66(2):142-7. 10.1016/j.jhin.2007.02.015PMC711460117512634 doi:10.1016/j.jhin.2007.02.015 PubMed
152. GomersallCD, JoyntGM, HoOM, IpM, YapF, DerrickJL, et al. Transmission of SARS to healthcare workers. The experience of a Hong Kong ICU. Intensive Care Medicine2006;32(4):564-9. 10.1007/s00134-006-0081-1PMC707989016505989 doi:10.1007/s00134-006-0081-1 PubMed
153. GoreJ, LambertJA. Does use of an instant hand sanitizer reduce elementary school illness absenteeism?Journal of Family Practice2001;50(1):64. 11195483 PubMed
154. GostinLO, BayerR, FairchildAL. Ethical and legal challenges posed by severe acute respiratory syndrome: implications for the control of severe infectious disease threats. JAMA2003;290(24):3229-37. 10.1001/jama.290.24.322914693876 doi:10.1001/jama.290.24.3229 PubMed
155. GraltonJ, McLawsML. Protecting healthcare workers from pandemic influenza: N95 or surgical masks?Critical Care Medicine2010;38(2):657-67. 10.1097/ccm.0b013e3181b9e8b320095070 doi:10.1097/ccm.0b013e3181b9e8b3 PubMed
156. GuinanM, McGukinM, AliY. The effect of a comprehensive handwashing program on absenteeism in elementary schools. American Journal of Infection Control2002;30(4):217-20. 10.1067/mic.2002.12036612032496 doi:10.1067/mic.2002.120366 PubMed
157. GuptaAG, MoyerCA, SternDT. The economic impact of quarantine: SARS in Toronto as a case study. Journal of Infection2005;50(5):386-93. 10.1016/j.jinf.2004.08.006PMC711251515907545 doi:10.1016/j.jinf.2004.08.006 PubMed
158. Gwaltney JM Jr, HendleyJO. Transmission of experimental rhinovirus infection by contaminated surfaces. American Journal of Epidemiology1982;116:828-33. 10.1093/oxfordjournals.aje.a1134736293304 doi:10.1093/oxfordjournals.aje.a113473 PubMed
159. HanH, LiX, QuW, ShenT, XuF, GaoD, et al. The building and practice of the emergency isolation radiology information system at the department of radiology in polyclinic during the epidemic outbreak stage of SARS. Beijing Da Xue Xue Bao [Journal of Peking University]2003;35(Suppl):86-8. 12914227 PubMed
160. HaydenGF, HendleyJO, Gwaltney JM Jr. The effect of placebo and virucidal paper handkerchiefs on viral contamination of the hand and transmission of experimental rhinoviral infection. Journal of Infectious Diseases1985;152(2):403-7. 10.1093/infdis/152.2.4034031549 doi:10.1093/infdis/152.2.403 PubMed
161. HendleyJO, Gwaltney JM Jr. Mechanisms of transmission of rhinovirus infections. Epidemiologic Reviews1988;10:243-58. 2852117 PubMed
162. HensN, AyeleGM, GoeyvaertsN, AertsM, MossongJ, EdmundsJW, et al. Estimating the impact of school closure on social mixing behaviour and the transmission of close contact infections in eight European countries. BMC Infectious Diseases2009;9:187. 10.1186/1471-2334-9-187PMC279940819943919 doi:10.1186/1471-2334-9-187 PubMed
163. HeymannAD, HochI, ValinskyL, KokiaE, SteinbergDM. School closure may be effective in reducing transmission of respiratory viruses in the community. Epidemiology and Infection2009;137(10):1369-76. 10.1017/S095026880900255619351434 doi:10.1017/S0950268809002556 PubMed
164. HilburnJ, HammondBS, FendlerEJ, GroziakPA. Use of alcohol hand sanitizer as an infection control strategy in an acute care facility. American Journal of Infection Control2003;31(2):109-16. 10.1067/mic.2003.1512665745 doi:10.1067/mic.2003.15 PubMed
165. HilmarssonH, TraustasonBS, KristmundsdottirT, ThormarH. Virucidal activities of medium- and long-chain fatty alcohols and lipids against respiratory syncytial virus and parainfluenza virus type 2: comparison at different pH levels. Archives of Virology2007;152(1):2225-36. 10.1007/s00705-007-1063-517891329 doi:10.1007/s00705-007-1063-5 PubMed
166. HirschHH, SteffenI, FrancioliP, WidmerAF. Respiratory syncytial virus infections: measures in immunocompromised patients [Respiratorisches syncytial-virus (RSV)-infektion: massnahmen beim immunsupprimierten patienten]. Praxis2006;95(3):61-6. 10.1024/0369-8394.95.3.6116459735 doi:10.1024/0369-8394.95.3.61 PubMed
167. HoAS, SungJJ, Chan-YeungM. An outbreak of severe acute respiratory syndrome among hospital workers in a community hospital in Hong Kong. Annals of Internal Medicine2003;139(7):564-7. 10.7326/0003-4819-139-7-200310070-0000814530227 doi:10.7326/0003-4819-139-7-200310070-00008 PubMed
168. HsiehYH, KingCC, ChenCW, HoMS, HsuSB, WuYC. Impact of quarantine on the 2003 SARS outbreak: a retrospective modeling study. Journal of Theoretical Biology2007;244(4):729-36. 10.1016/j.jtbi.2006.09.015PMC709415717055533 doi:10.1016/j.jtbi.2006.09.015 PubMed
169. HugonnetS, LegrosD, RothC, Pessoa-SilvaCL. Nosocomial transmission of severe acute respiratory syndrome: better quality of evidence is needed. Clinical Infectious Diseases2007;45(12):1651. 10.1086/52372518190333 doi:10.1086/523725 PubMed
170. JiangS, HuangL, ChenX, WangJ, WuW, YinS. Ventilation of wards and nosocomial outbreak of severe acute respiratory syndrome among healthcare workers. Chinese Medical Journal2003;116(9):1293-7. 14527351 PubMed
171. JiangSP, HuangLW, WangJF, WuW, YinSM, ChenWX. A study of the architectural factors and the infection rates of healthcare workers in isolation units for severe acute respiratory syndrome. Chung-Hua Chieh Ho Ho Hu Hsi Tsa Chih [Chinese Journal of Tuberculosis & Respiratory Diseases]2003;26(10):594-7. 14633440 PubMed
172. JohnsonDF, DruceJD, BirchC, GraysonML. A quantitative assessment of the efficacy of surgical and N95 masks to filter influenza virus in patients with acute influenza infection. Clinical Infectious Diseases2009;49(2):275-7. 10.1086/60004119522650 doi:10.1086/600041 PubMed
173. JonesEW. "Co-operation in All Human Endeavour": quarantine and immigrant disease vectors in the 1918-1919 influenza pandemic in Winnipeg. Canadian Bulletin of Medical History2005;22(1):57-82. 10.3138/cbmh.22.1.5715977380 doi:10.3138/cbmh.22.1.57 PubMed
174. KarakayaZ, DuyuM, Yersel MN . Oral mucosal mouthwash with chlorhexidine does not reduce the incidence of ventilator-associated pneumonia in critically ill children: a randomised controlled trial. Australian Critical Care2021;35(4):336-44. [DOI: https://doi.org/10.1016/j.aucc.2021.06.011]10.1016/j.aucc.2021.06.01134376358 doi:10.1016/j.aucc.2021.06.011 PubMed
175. KawyannejadR, AminisamanJ, MohammadiS, AminiS, MirzaeiM, Karimpour H . Comparing the effects of orthodentol and chlorhexidine mouthwash on prevention of ventilator-associated pneumonia in patients of intensive care unit: a randomized controlled clinical trial . Scientific Journal of Kurdistan University of Medical Sciences2020;25(1):93-104. [DOI: 10.52547/sjku.25.1.93] doi:10.52547/sjku.25.1.93
176. Kaydos-DanielsSC, OlowokureB, ChangHJ, BarwickRS, DengJF, LeeML, et al. Body temperature monitoring and SARS fever hotline, Taiwan. Emerging Infectious Diseases2004;10(2):373-6. 10.3201/eid1002.030748PMC332290015030716 doi:10.3201/eid1002.030748 PubMed
177. KelsoJK, MilneGJ, KellyH. Simulation suggests that rapid activation of social distancing can arrest epidemic development due to a novel strain of influenza. BMC Public Health2009;9:117. 10.1186/1471-2458-9-117PMC268082819400970 doi:10.1186/1471-2458-9-117 PubMed
178. KhawKS, Ngan KeeWD, TamYH, WongMK, LeeSW. Survey and evaluation of modified oxygen delivery devices used for suspected severe acute respiratory syndrome and other high-risk patients in Hong Kong. Hong Kong Medical Journal2008;14(Suppl 5):27-31. 18941271 PubMed
179. KilabukoJH, NakaiS. Effects of cooking fuels on acute respiratory infections in children in Tanzania. International Journal of Environmental Research and Public Health2007;4(4):283-8. 10.3390/ijerph200704040003PMC373239818180538 doi:10.3390/ijerph200704040003 PubMed
180. KosugiY, IshikawaT, ChimuraY, AnnakaM, ShibazakiS, AdachiK, et al. Control of hospital infection of influenza: administration of neuraminidase inhibitor and cohort isolation of influenza patients. Kansenshogaku Zasshi [Journal of the Japanese Association for Infectious Diseases]2004;78(12):995-9. 10.11150/kansenshogakuzasshi1970.78.99515678974 doi:10.11150/kansenshogakuzasshi1970.78.995 PubMed
181. LamBC, LeeJ, LauYL. Hand hygiene practices in a neonatal intensive care unit: a multimodal intervention and impact on nosocomial infection. Pediatrics2004;114(5):e565-71. 10.1542/peds.2004-110715492360 doi:10.1542/peds.2004-1107 PubMed
182. LangeJH. Use of disposable face masks for public health protection against SARS. Journal of Epidemiology and Community Health2004;58(5):434. PMC173277615082747 PubMed
183. LarsonEL, LinSX, Gomez-PichardoC, Della-LattaP. Effect of antibacterial home cleaning and handwashing products on infectious disease symptoms: a randomized, double-blind trial. Annals of Internal Medicine2004;140(5):321-9. 10.7326/0003-4819-140-5-200403020-00007PMC208205814996673 doi:10.7326/0003-4819-140-5-200403020-00007 PubMed
184. LarsonEL, LinSX, Gomez-PichardoC, Della-LattaP. Effect of antibacterial home cleaning and handwashing products on infectious disease symptoms: a randomized, double-blind trial. Annals of Internal Medicine2004;140(5):321-9. 10.7326/0003-4819-140-5-200403020-00007PMC208205814996673 doi:10.7326/0003-4819-140-5-200403020-00007 PubMed
185. LarsonEL, CimiottiJ, HaasJ, ParidesM, NesinM, Della-LattaP, et al. Effect of antiseptic handwashing vs alcohol sanitizer on health care-associated infections in neonatal intensive care units. Archives of Pediatrics & Adolescent Medicine2005;159(4):377-83. 10.1001/archpedi.159.4.37715809394 doi:10.1001/archpedi.159.4.377 PubMed
186. LauJT, YangX, TsuiHY, PangE. SARS related preventive and risk behaviours practised by Hong Kong-mainland China cross border travellers during the outbreak of the SARS epidemic in Hong Kong. Journal of Epidemiology and Community Health2004;58(12):988-96. 10.1136/jech.2003.017483PMC173264715547057 doi:10.1136/jech.2003.017483 PubMed
187. LauJT, LeungPC, WongEL, FongC, ChengKF, ZhangSC, et al. The use of an herbal formula by hospital care workers during the severe acute respiratory syndrome epidemic in Hong Kong to prevent severe acute respiratory syndrome transmission, relieve influenza-related symptoms, and improve quality of life: a prospective cohort study. Alternative & Complementary Medicine2005;11(1):49-55. 10.1089/acm.2005.11.4915750363 doi:10.1089/acm.2005.11.49 PubMed
188. LeeGM, SalomonJA, FriedmanJF, HibberdPL, Ross-DegnanD, ZasloffE, et al. Illness transmission in the home: a possible role for alcohol-based hand gels. Pediatrics2005;115(4):852-60. 10.1542/peds.2004-085615805355 doi:10.1542/peds.2004-0856 PubMed
189. LeeVJ, YapJ, CookAR, ChenMI, TayJK, BarrI, et al. Effectiveness of public health measures in mitigating pandemic influenza spread: a prospective sero-epidemiological cohort study. Journal of Infectious Diseases2010;202(9):1319-26. 10.1086/65648020863233 doi:10.1086/656480 PubMed
190. LennellA, Kühlmann-BerenzonS, GeliP, HedinK, PeterssonC, CarsO, et al. Alcohol-based hand-disinfection reduced children's absence from Swedish day care centers. Acta Paediatrica2008;97(12):1672-80. 10.1111/j.1651-2227.2008.01057.x18945282 doi:10.1111/j.1651-2227.2008.01057.x PubMed
191. LimNA, TengO, NgCY, BaoLX, TambyahPA, QuekAM, et al. Repurposing povidone-iodine to reduce the risk of SARS-CoV-2 infection and transmission: a narrative review. Annals of Medicine2022;54(1):1488-99. [DOI: 10.1080/07853890.2022.2076902]PMC913241135594333 doi:10.1080/07853890.2022.2076902 PubMed
192. LipsitchM, CohenT, CooperB, RobinsJM, MaS, JamesL, et al. Transmission dynamics and control of severe acute respiratory syndrome. Science2003;300(5627):1966-70. 10.1126/science.1086616PMC276015812766207 doi:10.1126/science.1086616 PubMed
193. LuckinghamB. To mask or not to mask: a note on the 1918 Spanish influenza epidemic in Tucson. Journal of Arizona History1984;25(2):191-204. 11635217 PubMed
194. MaHJ, WangHW, FangLQ, JiangJF, WeiMT, LiuW, et al. A case-control study on the risk factors of severe acute respiratory syndromes among health care workers. Chung-Hua Liu Hsing Ping Hsueh Tsa Chih [Chinese Journal of Epidemiology]2004;25(9):741-4. 15555351 PubMed
195. MacIntyreCR. Cluster randomised controlled trial: hand hygiene and face mask use within 36 hours of index patient symptom onset reduces flu transmission to household contacts. Evidence-Based Medicine2010;15(2):48-9. 10.1136/ebm104320436121 doi:10.1136/ebm1043 PubMed
196. MaleczekM, ToemboelF, Van ErpM, ThalhammerF, RösslerB. Reusable respirators as personal protective equipment in clinical practice: User experience in times of a pandemic. Wiener Klinische Wochenschrift2022;134(13-4):522-8. 10.1007/s00508-022-02022-1PMC900181735412049 doi:10.1007/s00508-022-02022-1 PubMed
197. MaloneJD, BriganticR, MullerGA, GadgilA, DelpW, McMahonBH, et al. U.S. airport entry screening in response to pandemic influenza: modeling and analysis. Travel Medicine and Infectious Disease2009;7(4):181-91. 10.1016/j.tmaid.2009.02.006PMC718537919717097 doi:10.1016/j.tmaid.2009.02.006 PubMed
198. MarinJ, DragasAZ, MavsarB. Virus permeability of protective gloves used in medical practice. Zentralblatt fur Hygiene und Umweltmedizin [International Journal of Hygiene and Environmental Medicine]1991;191(5-6):516-22. 1652967 PubMed
199. McSweenyK, ColmanA, FancourtN, ParnellM, StantiallS, RiceG, et al. Was rurality protective in the 1918 influenza pandemic in New Zealand?New Zealand Medical Journal2007;120(1256):2579. 17589547 PubMed
200. MeisterTL, GottsaunerJM, SchmidtB, HeinenN, TodtD, AudebertF, et al. Mouthrinses against SARS-CoV-2 - high antiviral effectivity by membrane disruption in vitro translates to mild effects in a randomized placebo-controlled clinical trial. Virus Research2022;316:198791. 10.1016/j.virusres.2022.198791PMC905794935504446 doi:10.1016/j.virusres.2022.198791 PubMed
201. MielkeM, NassauerA. Pandemic influenza: nonpharmaceutical protective measures in ambulatory care. Fortschritte der Medizin2009;151(40):32-4. 19927914 PubMed
202. MikolajczykRT, AkmatovMK, RastinS, KretzschmarM. Social contacts of school children and the transmission of respiratory-spread pathogens. Epidemiology and Infection2008;136(6):813-22. 10.1017/S0950268807009181PMC287086717634160 doi:10.1017/S0950268807009181 PubMed
203. MoY, PhamTM, LimC, HorbyP, StewardsonAJ, HarbarthS, et al. The effect of hand hygiene frequency on reducing acute respiratory infections in the community: a meta-analysis. Epidemiology and Infection2022;150:e79. [DOI: 10.1017/S0950268822000516]PMC904452535445655 doi:10.1017/S0950268822000516 PubMed
204. MonsmaM, DayR, St ArnaudS. Handwashing. Journal of School Health1992;62(3):109-11. 10.1111/j.1746-1561.1992.tb06031.x1535673 doi:10.1111/j.1746-1561.1992.tb06031.x PubMed
205. Montero-VilchezT, Martinez-LopezA, Cuenca-BarralesC, Quiñones-VicoMI, Sierra-SanchezA, Molina-LeyvaA, et al. Assessment of hand hygiene strategies on skin barrier function during COVID-19 pandemic: a randomized clinical trial. Contact Dermatitis2022;86(4):276-85. [DOI: 10.1111/cod.14034]34954837 doi:10.1111/cod.14034 PubMed
206. Muñoz-BasagoitiJ, AlemanyA, Perez-ZsoltD, OuchiD, Raïch-ReguéD, TrinitéB, et al. Cetylpyridinim cholride mouthwashes to reduce the shedding of viable SARS-CoV-2. Topics in Antiviral Medicine2022;30(Suppl 1):181-2.
207. Nandrup-BusI. Mandatory handwashing in elementary schools reduces absenteeism due to infectious illness among pupils: a pilot intervention study. American Journal of Infection Control2009;37(10):820-6. 10.1016/j.ajic.2009.06.01219850374 doi:10.1016/j.ajic.2009.06.012 PubMed
208. NishiuraH, WilsonN, BakerMG. Quarantine for pandemic influenza control at the borders of small island nations. BMC Infectious Diseases2009;9:27. 10.1186/1471-2334-9-27PMC267084619284571 doi:10.1186/1471-2334-9-27 PubMed
209. O'CallaghanCA. Prevention of nosocomial respiratory syncytial virus infection. Lancet1993;341(8838):182. 8093787 PubMed
210. OlsenSJ, ChangHL, CheungTY, TangAF, FiskTL, OoiSP. Transmission of the severe acute respiratory syndrome on aircraft. New England Journal of Medicine2003;349(25):2416-22. 10.1056/NEJMoa03134914681507 doi:10.1056/NEJMoa031349 PubMed
211. OoiPL, LimS, ChewSK. Use of quarantine in the control of SARS in Singapore. American Journal of Infection Control2005;33(5):252-7. 10.1016/j.ajic.2004.08.007PMC711907815947741 doi:10.1016/j.ajic.2004.08.007 PubMed
212. OrellanoPW, GrassiA, ReynosoJI, PalmieriA, UezO, CarlinoO. Impact of school closings on the influenza A (H1N1) outbreak in Tierra del Fuego, Argentina. Pan American Journal of Public Health2010;27(3):226-9. 10.1590/s1020-4989201000030001020414512 doi:10.1590/s1020-49892010000300010 PubMed
213. PanchabhaiTS, DangayachNS, KrishnanA, KothariVM, KarnadKR. Oropharyngeal cleansing with 0.2% chlorhexidine for prevention of nosocomial pneumonia in critically ill patients: an open-label randomized trial with 0.01% potassium permanganate as control. Chest2009;135(5):1150-6. 10.1378/chest.08-132119420193 doi:10.1378/chest.08-1321 PubMed
214. PangXH, LiuDL, GongXH, XuFJ, LiuZJ, ZhangZ, et al. Study on the risk factors related to severe acute respiratory syndrome among close contacts in Beijing. Chung-Hua Liu Hsing Ping Hsueh Tsa Chih [Chinese Journal of Epidemiology]2004;25(8):674-6. 15555389 PubMed
215. PatelMK, HarrisJR, JuliaoP, NygrenB, WereV, KolaS, et al. Impact of a hygiene curriculum and the installation of simple handwashing and drinking water stations in rural Kenyan primary schools on student health and hygiene practices. American Journal of Tropical Medicine and Hygiene2012;87(4):594-601. 10.4269/ajtmh.2012.11-0494PMC351630622869631 doi:10.4269/ajtmh.2012.11-0494 PubMed
216. PittetD, HugonnetS, HarbarthS, MourougaP, SauvanV, TouveneauS, et al. Effectiveness of a hospital-wide programme to improve compliance with hand hygiene. Infection Control Programme (Erratum in: Lancet 2000 Dec 23-30;356(9248):2196). Lancet2000;356(9238):1307-12. 10.1016/s0140-6736(00)02814-211073019 doi:10.1016/s0140-6736(00)02814-2 PubMed
217. PrasadGV, NashMM, ZaltzmanJS. Handwashing precautions taken by renal transplant recipients for severe acute respiratory syndrome. Transplantation2004;77(12):1917. 10.1097/01.tp.0000131946.36777.0615223923 doi:10.1097/01.tp.0000131946.36777.06 PubMed
218. RabenauHF, KampfG, CinatlJ, DoerrHW. Efficacy of various disinfectants against SARS coronavirus. Journal of Hospital Infection2005;61(2):107-11. 10.1016/j.jhin.2004.12.023PMC713250415923059 doi:10.1016/j.jhin.2004.12.023 PubMed
219. ReynoldsDL, GarayJR, DeamondSL, MoranMK, GoldW, StyraR. Understanding, compliance and psychological impact of the SARS quarantine experience. Epidemiology and Infection2008;136(7):997-1007. 10.1017/S0950268807009156PMC287088417662167 doi:10.1017/S0950268807009156 PubMed
220. RichardsonA, HofacreK. Comparison of filtration efficiency of a N95 filtering facepiece respirator and surgical mask against viral aerosols. American Journal of Infection Control2010;38(5):E20.
221. RileyS, FraserC, DonnellyCA, GhaniAC, Abu-RaddadLJ, HedleyAJ. Transmission dynamics of the etiological agent of SARS in Hong Kong: impact of public health interventions. Science2003;300(5627):1961-6. 10.1126/science.108647812766206 doi:10.1126/science.1086478 PubMed
222. RodriguezCV, RietbergK, BaerA, Kwan-GettT, DuchinJ. Association between school closure and subsequent absenteeism during a seasonal influenza epidemic. Epidemiology2009;20(6):787-92. 10.1097/EDE.0b013e3181b5f3ec19770773 doi:10.1097/EDE.0b013e3181b5f3ec PubMed
223. RosenL, ManorO, EngelhardD, BrodyD, RosenB, PelegH, et al. Can a handwashing intervention make a difference? Results from a randomized controlled trial in Jerusalem preschools. Preventive Medicine2006;42(1):27-32. 10.1016/j.ypmed.2005.09.01216300823 doi:10.1016/j.ypmed.2005.09.012 PubMed
224. RosenthalVD, GuzmanS, SafdarN. Reduction in nosocomial infection with improved hand hygiene in intensive care units of a tertiary care hospital in Argentina. American Journal of Infection Control2005;33(7):392-7. 10.1016/j.ajic.2004.08.00916153485 doi:10.1016/j.ajic.2004.08.009 PubMed
225. SafiulinAA. UV sanitation of the air and surfaces for the purpose of preventing in-hospital viral respiratory infections. Gigiena i Sanitariia1972;37(10):99-101. 4355918 PubMed
226. Sánchez Barrueco Á, Mateos-MorenoMV, Martínez-BeneytoY, García-VázquezE, Campos GonzálezA, Zapardiel FerreroJ, et al. Effect of oral antiseptics in reducing SARS-CoV-2 infectivity: evidence from a randomized double-blind clinical trial. Emerging Microbes & Infections2022;11(1):1833-42. [DOI: 10.1080/22221751.2022.2098059]PMC933649835796097 doi:10.1080/22221751.2022.2098059 PubMed
227. SandrockC, StollenwerkN. Acute febrile respiratory illness in the ICU: reducing disease transmission. Chest2008;133(5):1221-31. 10.1378/chest.07-0778PMC709474818460521 doi:10.1378/chest.07-0778 PubMed
228. SattarSA, AbebeM, BuetiAJ, JampaniH, NewmanJ, HuaS. Activity of an alcohol-based hand gel against human adeno-, rhino-, and rotaviruses using the fingerpad method. Infection Control and Hospital Epidemiology2000;21(8):516-9. 10.1086/50179610968717 doi:10.1086/501796 PubMed
229. SchullMJ, StukelTA, VermeulenMJ, ZwarensteinM, AlterDA, ManuelDG, et al. Effect of widespread restrictions on the use of hospital services during an outbreak of severe acute respiratory syndrome. CMAJ2007;176(13):1827-32. 10.1503/cmaj.061174PMC189112217576979 doi:10.1503/cmaj.061174 PubMed
230. SealLA, SladeB, CargillI, AustD. Persistence factors in handwashes. American Journal of Infection Control2010;38(5):E18-9.
231. SealeH, CorbettS, DwyerDE, MacIntyreCR. Feasibility exercise to evaluate the use of particulate respirators by emergency department staff during the 2007 influenza season. Infection Control and Hospital Epidemiology2009;30(7):710-2. 10.1086/59925419496650 doi:10.1086/599254 PubMed
232. SeneviratneC, BalanP, KoK, UdawatteNS, LaiD, NgD, et al. Efficacy of commercial mouth-rinses on SARS-CoV-2 viral load in saliva: randomized control trial in Singapore. Infection2021;49:305–11. [DOI: 10.1007/s15010-020-01563-9]PMC773411033315181 doi:10.1007/s15010-020-01563-9 PubMed
233. Sevinç GülSN, DilsizA, Sağlık İ, AydınNN. Effect of oral antiseptics on the viral load of SARS-CoV-2: a randomized controlled trial. Dental and Medical Problems2022;59(3):357-63. 10.17219/dmp/15083135904769 doi:10.17219/dmp/150831 PubMed
234. SizunJ, BaronR, SoupreD, GirouxJD, ParscauLde. Nosocomial infections due to syncytial respiratory virus: which hygienic measures. Archives de Pediatrie1996;3(7):723-7. 10.1016/0929-693x(96)87097-78881187 doi:10.1016/0929-693x(96)87097-7 PubMed
235. SlaytonRB, MurphyJL, MorrisJ, FaithSH, OremoJ, OdhiamboA, et al. A cluster randomized controlled evaluation of the health impact of a novel antimicrobial hand towel on the health of children under 2 years old in rural communities in Nyanza Province, Kenya. American Journal of Tropical Medicine and Hygiene2016;94(2):437-44. 10.4269/ajtmh.14-0566PMC475193726643530 doi:10.4269/ajtmh.14-0566 PubMed
236. StebbinsS, DownsJS, VukotichCJ. Using nonpharmaceutical interventions to prevent influenza transmission in elementary school children: parent and teacher perspectives. Journal of Public Health Management and Practice2009;15(2):112-7. 10.1097/01.PHH.0000346007.66898.6719202410 doi:10.1097/01.PHH.0000346007.66898.67 PubMed
237. Stedman-SmithM, DuBoisCL, GreySF, KingsburyDM, Shakya S, Scofield J, et al. Outcomes of a pilot hand hygiene randomized cluster trial to reduce communicable infections among US office-based employees. Journal of Occupational and Environmental Medicine2015;57(4):374-80. 10.1097/JOM.0000000000000421PMC437472425719534 doi:10.1097/JOM.0000000000000421 PubMed
238. StonerMJ, CohenDM, FernandezS, BonsuBK. Physician handwashing: what do parents want?Journal of Hospital Infection2007;65(2):112-6. 10.1016/j.jhin.2006.10.00717174446 doi:10.1016/j.jhin.2006.10.007 PubMed
239. StukelTA, SchullMJ, GuttmannA, AlterDA, LiP, VermeulenMJ, et al. Health impact of hospital restrictions on seriously ill hospitalized patients: lessons from the Toronto SARS outbreak. Medical Care2008;46(9):991-7. 10.1097/MLR.0b013e318179252518725855 doi:10.1097/MLR.0b013e3181792525 PubMed
240. SvobodaT, HenryB, ShulmanL, KennedyE, ReaE, NgW, et al. Public health measures to control the spread of the severe acute respiratory syndrome during the outbreak in Toronto. New England Journal of Medicine2004;350(23):2353-61. 10.1056/NEJMoa03211115175437 doi:10.1056/NEJMoa032111 PubMed
241. TrachtSM, Del ValleSY, HymanJM. Mathematical modeling of the effectiveness of facemasks in reducing the spread of novel influenza a (H1N1). PLOS One2010;5(2):e9018. 10.1371/journal.pone.0009018PMC281871420161764 doi:10.1371/journal.pone.0009018 PubMed
242. UenoT, SaijoK. Prevention of adenovirus infection and antiviral activity of a hand disinfectant, Welpas. Nippon Ganka Gakkai Zasshi1990;94(1):44-8. 2163189 PubMed
243. UhariM, MottonenM. An open randomized controlled trial of infection prevention in child day-care centers. Pediatric Infectious Disease Journal1999;18(8):672-7. 10.1097/00006454-199908000-0000410462334 doi:10.1097/00006454-199908000-00004 PubMed
244. SandeMvan der, TeunisP, SabelR. Professional and home-made face masks reduce exposure to respiratory infections among the general population. PLOS One2008;3(7):e2618. 10.1371/journal.pone.0002618PMC244079918612429 doi:10.1371/journal.pone.0002618 PubMed
245. VesseyJA, SherwoodJJ, WarnerD, ClarkD. Comparing hand washing to hand sanitizers in reducing elementary school students' absenteeism. Pediatric Nursing2007;33(4):368-72. 17907739 PubMed
246. ViscusiDJ, BergmanM, SinkuleE, ShafferRE. Evaluation of the filtration performance of 21 N95 filtering face piece respirators after prolonged storage. American Journal of Infection Control2009;37(5):381-6. 10.1016/j.ajic.2008.09.021PMC713267919188003 doi:10.1016/j.ajic.2008.09.021 PubMed
247. ViscusiDJ, BergmanMS, EimerBC, ShafferRE. Evaluation of five decontamination methods for filtering facepiece respirators. Annals of Occupational Hygiene2009;53(8):815-27. 10.1093/annhyg/mep070PMC278173819805391 doi:10.1093/annhyg/mep070 PubMed
248. WangJX, FengHY, LiuD, ZhangZL, ShanAL, ZhuXJ, et al. Epidemiological characteristics of severe acute respiratory syndrome in Tianjin and the assessment of effectiveness on measures of control. Chung-Hua Liu Hsing Ping Hsueh Tsa Chih [Chinese Journal of Epidemiology]2003;24(7):565-9. 12975009 PubMed
249. WangHW, HeJ, ZhangPH, TangF, WangTB, LuanYH, et al. A case-control study on the mxA polymorphisms and susceptibility to severe acute respiratory syndromes. Chung-Hua Liu Hsing Ping Hsueh Tsa Chih [Chinese Journal of Epidemiology]2005;26(8):574-7. 16390004 PubMed
250. WeberJT, HughesJM. Beyond Semmelweis: moving infection control into the community. Annals of Internal Medicine2004;140(5):397-8. 10.7326/0003-4819-140-5-200403020-0001614996682 doi:10.7326/0003-4819-140-5-200403020-00016 PubMed
251. WenZ, LuJ, LiJ, LiN, ZhaoJ, WangJ, et al. Determining the filtration efficiency of half-face medical protection mask (N99) against viral aerosol. Aerobiologia2010;26(3):245-51. 10.1007/s10453-010-9160-4PMC708762232214626 doi:10.1007/s10453-010-9160-4 PubMed
252. WhiteC, KolbleR, CarlsonR, LipsonN. The impact of a health campaign on hand hygiene and upper respiratory illness among college students living in residence halls. Journal of American College Health2005;53(4):175-81. 10.3200/JACH.53.4.175-18115663066 doi:10.3200/JACH.53.4.175-181 PubMed
253. WilczynskiJ, TorbickaE, Brzozowska-BindaA, SzymanskaU. Breast feeding for prevention of viral acute respiratory diseases in infants. Medycyna Doswiadczalna i Mikrobiologia1997;49(3-4):199-206. 9554153 PubMed
254. Wilder-SmithA, PatonNI, GohKT. Low risk of transmission of severe acute respiratory syndrome on airplanes: the Singapore experience. Tropical Medicine and International Health2003;8(11):1035-7. [MEDLINE: 14629772]10.1046/j.1360-2276.2003.01133.xPMC716973314629772 doi:10.1046/j.1360-2276.2003.01133.x PubMed
255. Wilder-SmithA, LowJG. Risk of respiratory infections in health care workers: lessons on infection control emerge from the SARS outbreak. Southeast Asian Journal of Tropical Medicine and Public Health2005;36(2):481-8. 15916060 PubMed
256. WongTW, TamWW. Handwashing practice and the use of personal protective equipment among medical students after the SARS epidemic in Hong Kong. American Journal of Infection Control2005;33(10):580-6. 10.1016/j.ajic.2005.05.025PMC711910916330306 doi:10.1016/j.ajic.2005.05.025 PubMed
257. Yen M-Y, Lu Y-C, Huang P-H, Chen C-M, Chen Y-C, LinYE. Quantitative evaluation of infection control models in the prevention of nosocomial transmission of SARS virus to healthcare workers: implication to nosocomial viral infection control for healthcare workers. Scandinavian Journal of Infectious Diseases2010;42(6-7):510-5. 10.3109/0036554090358240020148749 doi:10.3109/00365540903582400 PubMed
258. YuIT, LiY, WongTW, TamW, ChanAT, LeeJH, et al. Evidence of airborne transmission of the severe acute respiratory syndrome virus. New England Journal of Medicine2004;350(17):1731-9. 10.1056/NEJMoa03286715102999 doi:10.1056/NEJMoa032867 PubMed
259. ZamoraJE, MurdochJ, SimchisonB, DayAG. Contamination: a comparison of 2 personal protective systems. Canadian Medical Association Journal2006;175(3):249-54. 10.1503/cmaj.060094PMC151342516880444 doi:10.1503/cmaj.060094 PubMed
260. ZhaiS, LiuW, YanB. Recent patents on treatment of severe acute respiratory syndrome (SARS). Recent Patents on Anti-infective Drug Discovery2007;2(1):1-10. 10.2174/15748910777956169818221160 doi:10.2174/157489107779561698 PubMed
261. ZhaoZ, ZhangF, XuM, HuangK, ZhongW, CaiW, et al. Description and clinical treatment of an early outbreak of severe acute respiratory syndrome (SARS) in Guangzhou, PR China. Journal of Medical Microbiology2003;52(8):715-20. 10.1099/jmm.0.05320-012867568 doi:10.1099/jmm.0.05320-0 PubMed
262. ContrerasJD, IslamM, MertensA, PickeringAJ, ArnoldBF, Benjamin-ChungJ, et al. Evaluation of an on-site sanitation intervention against childhood diarrhea and acute respiratory infection 1 to 3.5 years after implementation: extended follow-up of a cluster-randomized controlled trial in rural Bangladesh. PLOS Medicine2022;19(8):e1004041. 10.1371/journal.pmed.1004041PMC939483035939520 doi:10.1371/journal.pmed.1004041 PubMed
263. CrokeK, CovilleA, MvukiyeheE, DohouCJ, Zibika J-P, Stanus GhibL, et al. Effects of a community-driven water, sanitation, and hygiene program on Covid-19 symptoms, vaccine acceptance,and non-Covid illnesses: a cluster-randomized controlled trial in rural Democratic Republic of Congo. Tropical Medicine & International Health2022;27(9):795-802. [DOI: 10.1111/tmi.13799]PMC934978835832019 doi:10.1111/tmi.13799 PubMed
264. DelaugerreC, FoissacF, AbdoulH, MassonG, ChoupeauxL, DufourE, et al. Prevention of SARS-CoV-2 transmission during a large, live, indoor gathering (SPRING): a non-inferiority, randomised, controlled trial. Lancet Infectious Diseases2022;22:341–8. 10.1016/S1473-3099(21)00673-3PMC862609434843662 doi:10.1016/S1473-3099(21)00673-3 PubMed
265. LoebM, BartholomewA, HashmiM, TarhuniW, HassanyM, YoungsterM, et al. Medical masks versus N95 respirators for preventing COVID-19 among health care workers. A randomized trial. Annals of Internal Medicine2022;0:0. [DOI: 10.7326/M22-1966]PMC970744136442064 doi:10.7326/M22-1966 PubMed
266. NCT04296643. Medical masks vs N95 respirators for COVID-19. Clinicaltrials.gov/show/NCT04296643 first received March 5, 2020.
267. VarelaAR, GurruchagaAP, RestrepoSR, MartinJD, LandazabalYD, Tamayo-CabezaG, et al. Effectiveness and adherence to closed face shields in the prevention of COVID-19 transmission: a non-inferiority randomized controlled trial in a middle-income setting (COVPROSHIELD). Trials2022;23(1):698. [DOI: 10.1186/s13063-022-06606-0]PMC939162335987694 doi:10.1186/s13063-022-06606-0 PubMed
268. BrassA, ShoubridgeA, CrottyM, MorawskaL, BellS, QiaoM, et al. Prevention of SARS-CoV-2 (COVID-19) transmission in residential aged care using ultraviolet light (PETRA): a two-arm crossover randomised controlled trial protocol. BMC Infectious Diseases2021;21:967. [DOI: https://doi.org/10.1186/s12879-021-06659-7]10.1186/s12879-021-06659-7PMC844671934535091 doi:10.1186/s12879-021-06659-7 PubMed
269. NCT03454009. Kent State University / Price Chopper Wellness Promotion Study. clinicaltrials.gov/show/NCT03454009 (first date received March 5 2018).
270. NCT04267952. Hand hygiene intervention program on primary school students' health outcomes and absenteeism in school. Clinicaltrials.gov/show/NCT04267952 (first received Feb 13 2020).
271. NCT04471766. Locally produced cloth face mask and COVID-19 Llke illness prevention. clinicaltrials.gov/ct2/show/NCT04471766 (first received July 15, 2020). [TRIAL REGISTRY: NCT04471766]
272. AbaluckJ, KwongLH, StyczynskiA, HaqueA, KabirMA, Bates-JeffriesE, et al. Can face masks reduce transmission of SARS-CoV-2 in Bangladesh? A cluster randomized controlled trial. osf.io/23mws/ accessed 13 June 2022.
273. AbaluckJ, KwongLH, StyczynskiA, HaqueA, KabirMA, Bates-JeffriesE, et al. The impact of community masking on COVID-19: a cluster-randomized trial in Bangladesh. CEGA Working Paper Series No. WPS-179 2021 (accessed 13 June 2022). [DOI: 10.26085/C3FS3C]PMC903694234855513 doi:10.26085/C3FS3C PubMed
274. ACTRN12610000887077. Face masks in the protection of healthcare workers to pandemic influenza and emerging infections [Economic, social and cross cultural issues in non-pharmaceutical protection of front line responders to pandemic influenza and emerging infections]. www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=336078 (first received 18 October).
275. AielloAE, LarsonEL. What is the evidence for a causal link between hygiene and infections?Lancet2002;2(2):103-10.10.1016/s1473-3099(02)00184-611901641 doi:10.1016/s1473-3099(02)00184-6 PubMed
276. AmmannP, UlyteA, HaileSR, PuhanMA, KriemlerS, RadtkeT. Perceptions towards mask use in school children during the SARS-CoV-2 pandemic: the Ciao Corona Study. Swiss Medical Weekly2022;152:w30165.10.4414/smw.2022.w3016535748765 doi:10.4414/smw.2022.w30165 PubMed
277. ArnoldBF, NullC, LubyS, UnicombL, StewartCP, DeweyKG, et al. Cluster-randomised controlled trials of individual and combined water, sanitation, hygiene and nutritional interventions in rural Bangladesh and Kenya: the WASH benefits study design and rationale. BMJ Open2013;3:e003476.10.1136/bmjopen-2013-003476PMC375897723996605 doi:10.1136/bmjopen-2013-003476 PubMed
278. AtkinsD, BestD, BrissPA, EcclesM, Falck-YtterY, FlottorpS, et al, GRADE Working Group. Grading quality of evidence and strength of recommendations. BMJ2004;328(7454):1490.10.1136/bmj.328.7454.1490PMC42852515205295 doi:10.1136/bmj.328.7454.1490 PubMed
279. BartoszkoJJ, FarooqiMA, AlhazzaniW, LoebM. Medical masks vs N95 respirators for preventing COVID-19 in healthcare workers: a systematic review and meta-analysis of randomized trials. Influenza and Other Respiratory Viruses2020;14(4):365-73. [DOI: 10.1111/irv.12745] [PMID: 32246890]PMC7298295 doi:10.1111/irv.12745 PubMed
280. BonnD. Spared an influenza pandemic for another year?Lancet1997;349(9044):36.10.1016/S0140-6736(05)62175-78999266 doi:10.1016/S0140-6736(05)62175-7 PubMed
281. BootsmaMC, FergusonNM. The effect of public health measures on the 1918 influenza pandemic in U.S. cities. Proceedings of the National Academy of Sciences of the United States of America (PNAS)2007;E-pub ahead of print:1-6. [DOI: 10.1073 /pnas.0611071104]10.1073/pnas.0611071104PMC184986817416677 doi:10.1073/pnas.0611071104 PubMed
282. BroderickMP, HansenCJ, RussellKL. Exploration of the effectiveness of social distancing on respiratory pathogen transmission implicates environmental contributions. Journal of Infectious Diseases2008;198(10):1420-6. [DOI: 10.1086/592711]PMC710983918823270 doi:10.1086/592711 PubMed
283. BrosseauLM, Sietsema M. Masks-for-all for COVID-19 not based on sound data. www.cidrap.umn.edu/news-perspective/2020/04/commentary-masks-all-covid-19-not-based-sound-data (accessed 20 April 2020).
284. BundgaardH, BundgaardJS, Raaschou-PedersenDE, MariagerAF, SchytteN, BuchwaldCvon. Face masks for the prevention of COVID-19 - Rationale and design of the randomised controlled trial DANMASK-19. Danish Medical Journal2020;67(9):A05200363.32829745 PubMed
285. ByambasurenO, BellerE, ClarkJ, CollignonP, GlasziouP. The effect of eye protection on SARS-CoV-2 transmission: a systematic review. Antimicrobial Resistance & Infection Control2021;10(1):156. [DOI: 10.1186/s13756-021-01025-3]PMC856712834736533 doi:10.1186/s13756-021-01025-3 PubMed
286. CassellMM, HalperinDT, SheltonJD, StantonD. Risk compensation: the achilles’ heel of innovations in HIV prevention?BMJ2006;332:605–7.10.1136/bmj.332.7541.605PMC139775216528088 doi:10.1136/bmj.332.7541.605 PubMed
287. Centers for Disease Control and Prevention. Infection control guidance for the prevention and control of influenza in acute-care facilities. www.cdc.gov/flu/professionals/infectioncontrol/healthcarefacilities.htm (accessed 3 March 2006).
288. Centers for Disease Control and Prevention. 2004-2005 Interim guidance for the use of masks to control influenza transmission. www.cdc.gov/flu/professionals/infectioncontrol/maskguidance.htm (accessed 3 March 2006).
289. ChardAN, FreemanMC. Design, intervention fidelity, and behavioral outcomes of a school-based water, sanitation, and hygiene cluster-randomized trial in Laos. International Journal of Environmental Research and Public Health2018;15(4):570.10.3390/ijerph15040570PMC592361229565302 doi:10.3390/ijerph15040570 PubMed
290. ChristensenG, DentzHN, PickeringAJ, BourdierT, ArnoldBF, Colford JM Jr. Pilot cluster randomized controlled trials to evaluate adoption of water, sanitation, and hygiene interventions and their combination in rural western Kenya. American Journal of Tropical Medicine and Hygiene2015;92(2):437-47.10.4269/ajtmh.14-0138PMC434735325422394 doi:10.4269/ajtmh.14-0138 PubMed
291. ChuDK, AklEA, DudaS, SoloK, YaacoubS, SchünemannHJ. Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis. Lancet2020;395(10242):1973-87. [DOI: 10.1016/ S0140-6736(20)31142-9]10.1016/S0140-6736(20)31142-9PMC726381432497510 doi:10.1016/S0140-6736(20)31142-9 PubMed
292. Claessen J-P, BatesS, SherlockK, SeeparsandF, WrightR. Designing interventions to improve tooth brushing. International Dental Journal2008;58(Suppl 5):307–20.
293. ClarkJM, SandersS, CarterM, HoneymanD, CleoG, AuldY, et al. Improving the translation of search strategies using the Polyglot Search Translator: a randomized controlled trial. Journal of the Medical Library Association2020;108(2):195-207.10.5195/jmla.2020.834PMC706983332256231 doi:10.5195/jmla.2020.834 PubMed
294. CoroiuA, MoranC, LindsayBL, GellerAC. Parent-for-child mask behavior during the COVID-19 pandemic in Canada and the United States: an investigation of attitudes, norms, and perceived control using the theory of planned behavior. Preventive Medicine Reports2021;24:101533. [DOI: 10.1016/j.pmedr.2021.101533]PMC840108034485027 doi:10.1016/j.pmedr.2021.101533 PubMed
295. CurtisV, BiranA. Dirt, disgust, and disease: Is hygiene in our genes?Perspectives in Biology and Medicine2001;44(1):17-31.10.1353/pbm.2001.000111253302 doi:10.1353/pbm.2001.0001 PubMed
296. DemicheliV, JeffersonT, FerroniE, RivettiA, Di PietrantonjC. Vaccines for preventing influenza in healthy adults. Cochrane Database of Systematic Reviews2018, Issue 2. Art. No: CD001269. [DOI: 10.1002/14651858.CD001269.pub6]PMC649118429388196 doi:10.1002/14651858.CD001269.pub6 PubMed
297. DemicheliV, JeffersonT, Di PietrantonjC, FerroniE, ThorningS, ThomasRE, et al. Vaccines for preventing influenza in the elderly. Cochrane Database of Systematic Reviews2018, Issue 2. Art. No: CD004876. [DOI: 10.1002/14651858.CD004876.pub4]PMC649110129388197 doi:10.1002/14651858.CD004876.pub4 PubMed
298. DenfordS, TowlerL, AliB, Treneman-EvansG, BloomerR, PetoTE, et al. Feasibility and acceptability of daily testing at school as an alternative to self-isolation following close contact with a confirmed case of COVID-19: a qualitative analysis. BMC Public Health2022;22:742.10.1186/s12889-022-13204-xPMC900757735418065 doi:10.1186/s12889-022-13204-x PubMed
299. DentzH, NullC, PickeringA, StewartC. WASH Benefits Kenya randomized controlled trial - implementation paper & documents. https://osf.io/26r59/2017.
300. DreibelbisR, WinchPJ, LeontsiniE, HullandKR, RamPK, UnicombL, et al. The integrated behavioural model for water, sanitation, and hygiene: a systematic review of behavioural models and a framework for designing and evaluating behaviour change interventions in infrastructure restricted settings. BMC Public Health2013;13:1015.10.1186/1471-2458-13-1015PMC423135024160869 doi:10.1186/1471-2458-13-1015 PubMed
301. ElfleinJ. Number of influenza cases in the United States from 2010-2017. www.statista.com/statistics/861113/estimated-number-of-flu-cases-us/ (accessed prior to 2 November 2020).
302. EllisM. Evaluating strategies to prevent methicillin-resistant Staphylococcus Aureus skin and soft tissue infections in military trainees (Methicillin-resistant Staphylococcus Aureus (MRSA) skin and soft tissue infection (SSTI) prevention in military trainees]. clinicaltrials.gov/ct2/show/study/NCT01105767 April 16, 2010.
303. ErasmusV, HuisA, OenemaA, Van EmpelenP, BoogMC, Van BeeckEH, et al. The ACCOMPLISH study. A cluster randomised trial on the cost-effectiveness of a multicomponent intervention to improve hand hygiene compliance and reduce healthcare associated infections. BMC Public Health [Internet]2011;11:721.10.1186/1471-2458-11-721PMC320426021943482 doi:10.1186/1471-2458-11-721 PubMed
304. FongMW, GaoH, WongJY, Xiao J, Shiu EY, Ryu S, et al. Nonpharmaceutical measures for pandemic influenza in nonhealthcare settings - social distancing measures. Emerging Infectious Diseases2020;26(5):976-84.10.3201/eid2605.190995PMC718190832027585 doi:10.3201/eid2605.190995 PubMed
305. FretheimA, ElgersmaIH, HelleveA, ElstrømP, KacelnikO, HemkensLG. Glasses against transmission of 1 SARS-CoV-2 in the community (GLASSY): a pragmatic randomized trial. medRxiv preprint:(accessed 20 September 2022). [DOI: 10.1101/2022.07.31.22278223] doi:10.1101/2022.07.31.22278223
306. FungIC, CairncrossS. Effectiveness of handwashing in preventing SARS: a review. Tropical Medicine and International Health2006;11(11):1749-58.10.1111/j.1365-3156.2006.01734.xPMC716973217054756 doi:10.1111/j.1365-3156.2006.01734.x PubMed
307. GlanzK, RimerBK, ViswanathK, editors. Health Behavior and Health Education: Theory, Research, and Practice. 4th edition. San Francisco (CA): Jossey-Bass, 2008.
308. GRADEpro GDT. Version accessed 27 April 2020. Hamilton (ON): McMaster University (developed by Evidence Prime), 2015. Available at gradepro.org.
309. GreenhalghT, SchmidMB, Czypionka T, Bassler D, Gruer L. Face masks for the public during the covid-19 crisis. BMJ2020;369:m1435.10.1136/bmj.m143532273267 doi:10.1136/bmj.m1435 PubMed
310. HartingerSM, LanataCF, HattendorfJ, GilAI, VerasteguiH, OchoaT, et al. A community randomised controlled trial evaluating a home-based environmental intervention package of improved stoves, solar water disinfection and kitchen sinks in rural Peru: Rationale, trial design and baseline findings. Contemporary Clinical Trials2011;32(6):864–73.10.1016/j.cct.2011.06.00621762789 doi:10.1016/j.cct.2011.06.006 PubMed
311. HartingerSM, LanataCF, GilAI, HattendorfJ, VerasteguiH, MäusezahlD. Combining interventions: Improved chimney stoves, kitchen sinks and solar disinfection of drinking water and kitchen clothes to improve home hygiene in rural Peru. Field Actions Science Report http://factsreports.revues.org/1627 accessed 3 May 2013;6:1 SPL.
312. HigginsJP, ThompsonSG. Quantifying heterogeneity in a meta-analysis. Statistics in Medicine2002;21(11):1539-58.10.1002/sim.118612111919 doi:10.1002/sim.1186 PubMed
313. HigginsJP, ThompsonSG, DeeksJJ, AltmanDG. Measuring inconsistency in meta-analyses. BMJ2003;327(7414):557-60.10.1136/bmj.327.7414.557PMC19285912958120 doi:10.1136/bmj.327.7414.557 PubMed
314. HigginsJP, GreenS, editor(s). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 (updated March 2011). The Cochrane Collaboration, 2011. Available from training.cochrane.org/handbook/archive/v5.1/.
315. HigginsJP, EldridgeS, LiT. Chapter 23.1.5 Approximate analyses of cluster-randomized trials for a meta-analysis: inflating standard errors. In: Higgins JP, Thomas J, Chandler J, Cumpston M, Li T, Page MJ, Welch VA, editor(s). Cochrane Handbook for Systematic Reviews of Interventions Version 6.2 (updated February 2021). Cochrane, 2021. Available from training.cochrane.org/handbook.
316. HigginsJP, EldridgeS, LiT. Chapter 23.3.4 How to include multiple groups from one study. In: Higgins JP, Thomas J, Chandler J, Cumpston M, Li T, Page MJ, Welch VA, editor(s). Cochrane Handbook for Systematic Reviews of Interventions Version 6.2 (updated February 2021). Cochrane, 2021. Available from training.cochrane.org/handbook.
317. HowardJ, HuangA, LiZ, TufekciZ, ZdimalV, WesthuizenHvan der, et al. Face masks against COVID-19: an evidence review. www.preprints.org/manuscript/202004.0203/v1 (accessed 20 April 2020). [DOI: 10.20944/preprints202004.0203.v1] doi:10.20944/preprints202004.0203.v1
318. HuisA, SchoonhovenL, GrolR, DondersR, HulscherM, AchterbergTvan. Impact of a team and leaders-directed strategy to improve nurses’ adherence to hand hygiene guidelines: a cluster randomised trial. International Journal of Nursing Studies2013;50:464-74.10.1016/j.ijnurstu.2012.08.00422939048 doi:10.1016/j.ijnurstu.2012.08.004 PubMed
319. HullandKR, LeontsiniE, DreibelbisR, UnicombL, AfrozA, DuttaNC, et al. Designing a handwashing station for infrastructure-restricted communities in Bangladesh using the integrated behavioural model for water, sanitation and hygiene interventions (IBM-WASH). BMC Public Health2013;13(1):877.10.1186/1471-2458-13-877PMC385255424060247 doi:10.1186/1471-2458-13-877 PubMed
320. JeffersonT, DemicheliV, RivettiD, JonesM, Di PietrantonjC, RivettiA. Antivirals for influenza in healthy adults: systematic review. Lancet2006;367(9507):303-13. [DOI: 10.1016/S0140‐6736(06) 67970-1]10.1016/S0140-6736(06)67970-116443037 doi:10.1016/S0140-6736(06)67970-1 PubMed
321. JeffersonT, JonesM, DoshiP, Del MarC, HamaR, ThompsonM, et al. Neuraminidase inhibitors for preventing and treating influenza in adults and children. Cochrane Database of Systematic Reviews2014, Issue 4. Art. No: CD008965. [DOI: 10.1002/14651858.CD008965.pub4]PMC646496924718923 doi:10.1002/14651858.CD008965.pub4 PubMed
322. JeffersonT, RivettiA, Di PietrantonjC, DemicheliV. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews2018, Issue 2. Art. No: CD004879. [DOI: 10.1002/14651858.CD004879.pub5]PMC649117429388195 doi:10.1002/14651858.CD004879.pub5 PubMed
323. KaewchanaS, SimmermanM, SomrongthongR, SuntarattiwongP, LertmaharitS, ChotipitayasunondhT. Effect of intensive hand washing education on hand washing behaviors in Thai households with an influenza-positive child in urban Thailand. Asia-Pacific Journal of Public Health2012;24(4):577-85.10.1177/101053951039372821362672 doi:10.1177/1010539510393728 PubMed
324. KendrickAS. Training to ensure healthy child day care programs. Pediatrics1994;94(6 II):1108-110.7971079 PubMed
325. KirschtJP. The Health Belief Model and illness behavior. Health Education & Behavior1974;2(4):387–408.
326. KitamuraT, SatomuraK, KawamuraT, YamadaS, TakashimaK, SuganumaN. Can we prevent influenza-like illnesses by gargling?Japanese Society of Internal Medicine2007;46(18):1623-4. [DOI: 10.2169/internalmedicine.46.0104]17878657 doi:10.2169/internalmedicine.46.0104 PubMed
327. KutterJS, SpronkenMI, FraaijPL, FouchierRA, HerfstS. Transmission routes of respiratory viruses among humans. Current Opinion in Virology2018;28:142-51. [DOI: 10.1016/j.coviro.2018.01.001] [ISSN 1879-6257]PMC710268329452994 doi:10.1016/j.coviro.2018.01.001 PubMed
328. KwongL, AbaluckJ, Benjamin-ChungJ, LubyS. Can face masks reduce transmission of SARS-CoV-2 in Bangladesh? A cluster randomized controlled trial. osf.io/vzdh6/ 2021 (accessed 13 June 2022).
329. LefebvreC, ManheimerE, GlanvilleJ. Chapter 6: Searching for studies. In: Higgins JP, Green S, editor(s). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 (updated March 2011). The Cochrane Collaboration, 2011. Available from training.cochrane.org/handbook/archive/v5.1/.
330. LeungNH. Transmissibility and transmission of respiratory viruses. Nature Reviews Microbiology2021;19(8):528-45.10.1038/s41579-021-00535-6PMC798288233753932 doi:10.1038/s41579-021-00535-6 PubMed
331. LinYC, MalottRJ, WardL, KiplagatL, PabbarajuK, GillK, et al. Detection and quantification of infectious severe acute respiratory coronavirus-2 in diverse clinical and environmental samples. Scientific Reports2022;12(1):5418. [DOI: 10.1038/s41598-022-09218-5]PMC896708735354854 doi:10.1038/s41598-022-09218-5 PubMed
332. LongY, HuT, LiuL, ChenR, Guo Q, YangL, et al. Effectiveness of N95 respirators versus surgical masks against influenza: a systematic review and meta-analysis. Journal of Evidence-Based Medicine2020;13(2):93-101. [DOI: 10.1111/jebm.12381]PMC722834532167245 doi:10.1111/jebm.12381 PubMed
333. LubySP, RahmanM, ArnoldBF, UnicombL, AshrafS, WinchPJ, et al. Effects of water quality, sanitation, handwashing, and nutritional interventions on diarrhoea and child growth in rural Bangladesh: a cluster randomised controlled trial. Lancet Global Health2018;6(3):e302-e15.10.1016/S2214-109X(17)30490-4PMC580971829396217 doi:10.1016/S2214-109X(17)30490-4 PubMed
334. MarshallIJ, A Noel-StorrA, KuiperJ, ThomasJ, WallaceBD. Machine learning for identifying randomized controlled trials: an evaluation and practitioner's guide. Research Synthesis Methods2018;9(4):602-14. [DOI: 10.1002/jrsm.1287]PMC603051329314757 doi:10.1002/jrsm.1287 PubMed
335. MbakayaBC, LeePH, LeeRL. Hand hygiene intervention strategies to reduce diarrhoea and respiratory infections among schoolchildren in developing countries: a systematic review. International Journal of Environmental Research and Public Health2017;14(4):371.10.3390/ijerph14040371PMC540957228368323 doi:10.3390/ijerph14040371 PubMed
336. McKenzieJE, PriestP, AudasR, PooreMR, BruntonCR, ReevesLM. Hand sanitisers for reducing illness absences in primary school children in New Zealand: a cluster randomised controlled trial study protocol. Trials2010;11:7.10.1186/1745-6215-11-7PMC282373720096128 doi:10.1186/1745-6215-11-7 PubMed
337. MeadowsE, Le SauxN. A systematic review of the effectiveness of antimicrobial rinse-free hand sanitizers for prevention of illness-related absenteeism in elementary school children. BMC Public Health2004;4:50. [DOI: 10.1186/1471-2458-4-50]PMC53410815518593 doi:10.1186/1471-2458-4-50 PubMed
338. Microsoft Corporation. Microsoft Excel. Available from: https://office.microsoft.com/excel2018.
339. MoncionK, YoungK, TunisM, RempelS, StirlingR, ZhaoL. Effectiveness of hand hygiene practices in preventing influenza virus infection in the community setting: a systematic review. Canada Communicable Disease Report2019;45(1):12-23.10.14745/ccdr.v45i01a02PMC646112231015816 doi:10.14745/ccdr.v45i01a02 PubMed
340. MontoAS, DavenportFM, NapierJA, Francis T Jr. Effect of vaccination of a school-age population upon the course of an A2-Hong Kong influenza epidemic. Bulletin of the World Health Organization1969;41(3):537-42.PMC24277275309469 PubMed
341. NajninN, LederK, QadriF, ForbesA, UnicombL, WinchPJ, et al. Impact of adding hand-washing and water disinfection promotion to oral cholera vaccination on diarrhoea-associated hospitalization in Dhaka, Bangladesh: Evidence from a cluster randomized control trial International. Journal of Epidemiology2017;46(6):2056-66.10.1093/ije/dyx187PMC583738429025064 doi:10.1093/ije/dyx187 PubMed
342. NullC, StewartCP, PickeringAJ, DentzHN, ArnoldBF, ArnoldCD, et al. Effects of water quality, sanitation, handwashing, and nutritional interventions on diarrhoea and child growth in rural Kenya: a cluster-randomised controlled trial. Lancet Global Health2018;6:e316–29.10.1016/S2214-109X(18)30005-6PMC580971729396219 doi:10.1016/S2214-109X(18)30005-6 PubMed
343. OffedduV, YungCF, LowMS, TamCC. Effectiveness of masks and respirators against respiratory infections in healthcare workers: a systematic review and meta-analysis. Clinical Infectious Diseases2017;65(11):1934-42. [DOI: 10.1093/cid/cix681]PMC710811129140516 doi:10.1093/cid/cix681 PubMed
344. OnakpoyaIJ, HeneghanCJ, SpencerEA, BrasseyJ, PlüddemannA, EvansDH, et al. SARS-CoV-2 and the role of close contact in transmission: a systematic review [version 3; peer review: 2 approved, 1 approved with reservations, 1 not approved]. F1000Research2022;10:280. [DOI: 10.12688/f1000research.52439.3]PMC963648736398277 doi:10.12688/f1000research.52439.3 PubMed
345. OnakpoyaIJ, HeneghanCJ, SpencerEA, BrasseyJ, RoscaEC, MaltoniS. Viral cultures for assessing fomite transmission of SARS-CoV-2: a systematic review and meta-analysis. Journal of Hospital Infection2022;130:63-94. [DOI: 10.1016/j.jhin.2022.09.007] [PMC9473144] [PMID: 36115620]PMC9473144 doi:10.1016/j.jhin.2022.09.007 PubMed
346. OngSW, TanYK, ChiaPY, LeeTH, NgOT, WongMS, et al. Air, surface environmental, and personal protective equipment contamination by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from a symptomatic patient. JAMA2020;323(16):1610-2.10.1001/jama.2020.3227PMC705717232129805 doi:10.1001/jama.2020.3227 PubMed
347. ParvezSM, AzadR, RahmanM, UnicombL, RamPK, NaserAM, et al. Achieving optimal technology and behavioral uptake of single and combined interventions of water, sanitation hygiene and nutrition, in an efficacy trial (WASH benefits) in rural Bangladesh. Trials2018;19(1):358.10.1186/s13063-018-2710-8PMC603420729976251 doi:10.1186/s13063-018-2710-8 PubMed
348. PerkinsHW, editor. The Social Norms Approach to Preventing School and College Age Substance Abuse: a Handbook for Educators, Counselors, and Clinicians. San Francisco (CA): Jossey-Bass, 2003.
349. PickeringAJ, NullC, WinchPJ, MangwaduG, ArnoldBF, PrendergastAJ, et al. The WASH Benefits and SHINE trials: interpretation of WASH intervention effects on linear growth and diarrhoea. Lancet Global Health2019;7(8):e1139-46.10.1016/S2214-109X(19)30268-231303300 doi:10.1016/S2214-109X(19)30268-2 PubMed
350. QadriF, AliM, ChowdhuryF, KhanAI, SahaA, KhanIA, et al. Feasibility and effectiveness of oral cholera vaccine in an urban endemic setting in Bangladesh: a cluster randomised open-label trial. Lancet2015;386(10001):1362–71.10.1016/S0140-6736(15)61140-026164097 doi:10.1016/S0140-6736(15)61140-0 PubMed
351. RabieT, CurtisV. Handwashing and risk of respiratory infections: a quantitative systematic review. Tropical Medicine & International Health2006;11(3):258-67.10.1111/j.1365-3156.2006.01568.xPMC716966416553905 doi:10.1111/j.1365-3156.2006.01568.x PubMed
352. Radonovich LJ Jr, BessesenMT, CummingsDA, EaganA, GaydosA, GibertC, et al. The respiratory protection effectiveness clinical trial (ResPECT): a cluster-randomized comparison of respirator and medical mask effectiveness against respiratory infections in healthcare personnel. BMC Infectious Diseases2016;16:243. [DOI: 10.1186/s12879-016-1494-2]PMC489024727255755 doi:10.1186/s12879-016-1494-2 PubMed
353. RahmanM, AshrafS, UnicombL, MainuddinAK, ParvezSM, BegumF, et al. WASH Benefits Bangladesh trial: system for monitoring coverage and quality in an efficacy trial. Trials2018;19:360.10.1186/s13063-018-2708-2PMC603430029976234 doi:10.1186/s13063-018-2708-2 PubMed
354. RanL, ChenX, WangY, WuW, ZhangL, TanX. Risk factors of healthcare workers with corona virus disease 2019: a retrospective cohort study in a designated hospital of Wuhan in China. Clinical Infectious Diseases 2020 Mar 17 [Epub ahead of print]. [DOI: 10.1093/cid/ciaa287] [PMID: 32179890]PMC7184482 doi:10.1093/cid/ciaa287 PubMed
355. RengasamyS, EimerB, ShafferRE. Simple respiratory protection - evaluation of the filtration performance of cloth masks and common fabric materials against 20-1000 nm size particles. Annals of Occupational Hygiene2010;54(7):789-98.10.1093/annhyg/meq044PMC731426120584862 doi:10.1093/annhyg/meq044 PubMed
356. RIVM. Health risks in a child daycare centre or preschool (0 to 4 year olds). Dutch National Institute for Public Health and the Environment (RIVM), Dutch National Centre for Hygiene and Safety (LCHV). Bilthoven (The Netherlands): The Institute2011.
357. Saunders-HastingsP, CrispoJA, SikoraL, KrewskiD. Effectiveness of personal protective measures in reducing pandemic influenza transmission: a systematic review and meta-analysis. Epidemics2017;20:1-20.10.1016/j.epidem.2017.04.00328487207 doi:10.1016/j.epidem.2017.04.003 PubMed
358. Savolainen-KopraC, HaapakoskiJ, PeltolaPA, ZieglerT, KorpelaT, AnttilaP, et al. STOPFLU: is it possible to reduce the number of days off in office work by improved hand-hygiene?Trials2010;11:69.10.1186/1745-6215-11-69PMC288998920525328 doi:10.1186/1745-6215-11-69 PubMed
359. SchwartzJL. The Spanish Flu, epidemics, and the turn to biomedical responses. American Journal of Public Health2018;108(11):1455-8.10.2105/AJPH.2018.304581PMC618778330252511 doi:10.2105/AJPH.2018.304581 PubMed
360. ShenM, ZengZ, SongB, YiH, HuT, ZhangY, et al. Neglected microplastics pollution in global COVID-19: disposable surgical masks. Science of the Total Environment2021;790:148130. [DOI: 10.1016/j.scitotenv.2021.148130]PMC816451534091337 doi:10.1016/j.scitotenv.2021.148130 PubMed
361. SidibeM. Formative Research in Schools: Review Document. London (UK): London School of Hygiene & Tropical Medicine, 2003.
362. SidibeM, ShuklaN, RustagiA. Inducing the habit of soap usage in an urban community setting. In: Proceedings of the 3rd WHO International Conference on Children’s Health and the Environment. Busan (Korea), 2009.
363. SmithJD, MacDougallCC, JohnstoneJ, CopesRA, SchwartzB, GarberGE. Effectiveness of N95 respirators versus surgical masks in protecting health care workers from acute respiratory infection: a systematic review and meta-analysis. Canadian Medical Association Journal2016;188(8):567-74. [DOI: 10.1503/cmaj.150835]PMC486860526952529 doi:10.1503/cmaj.150835 PubMed
364. SuessT, RemschmidtC, SchinkS, LuchtenbergM, HaasW, KrauseG, et al. Facemasks and intensified hand hygiene in a German household trial during the 2009/2010 influenza A (H1N1) pandemic: adherence and tolerability in children and adults. Epidemiology and Infection2011;139(12):1895-901.10.1017/S095026881000300621211103 doi:10.1017/S0950268810003006 PubMed
365. TeesingGR, ErasmusV, NieboerD, PetrignaniM, KoopmansMP, VosMC, et al. Increased hand hygiene compliance in nursing homes after a multimodal intervention: a cluster randomized controlled trial (HANDSOME). Infection Control and Hospital Epidemiology2020;41(10):1169-77.10.1017/ice.2020.31932748765 doi:10.1017/ice.2020.319 PubMed
366. TeesingGR, ErasmusV, PetrignaniM, KoopmansMP, GraafMde, VosMC, et al. Improving hand hygiene compliance in nursing homes: protocol for a cluster randomized controlled trial (HANDSOME Study). JMIR Research Protocols2020;9(5):e17419.10.2196/17419PMC722952732356772 doi:10.2196/17419 PubMed
367. ThomasRE, JeffersonT, LassersonTJ. Influenza vaccination for healthcare workers who work with the elderly. Cochrane Database of Systematic Reviews2010, Issue 2. Art. No: CD005187. [DOI: 10.1002/14651858.CD005187.pub3]20166073 doi:10.1002/14651858.CD005187.pub3 PubMed
368. UnicombL, BegumF, LeontsiniE, RahmanM, AshrafS, NaserAM, et al. WASH Benefits Bangladesh trial: management structure for achieving high coverage in an efficacy trial. Trials2018;19:359.10.1186/s13063-018-2709-1PMC603421829976247 doi:10.1186/s13063-018-2709-1 PubMed
369. Warren-GashC, FragaszyE, HaywardAC. Hand hygiene to reduce community transmission of influenza and acute respiratory tract infection: a systematic review. Influenza and Other Respiratory Viruses2013;7(5):738-49.10.1111/irv.12015PMC578120623043518 doi:10.1111/irv.12015 PubMed
370. World Health Organization (WHO). WHO Guidelines on Hand Hygiene in Health Care (advanced draft). Geneva (Switzerland): WHO, 2006.
371. World Health Organization Writing Group. Non pharmaceutical interventions for pandemic influenza, national and community measures. Emerging Infectious Diseases2006;12(1):88-94.10.3201/eid1201.051371PMC329141516494723 doi:10.3201/eid1201.051371 PubMed
372. World Health Organization. Infection prevention and control of epidemic- and pandemic-prone acute respiratory infections in health care. apps.who.int/iris/handle/10665/112656 (accessed prior to 2 November 2020).24983124 PubMed
373. World Health Organization. The global impact of respiratory disease. www.who.int/gard/publications/The_Global_Impact_of_Respiratory_Disease.pdf (accessed 15 March 2020).
374. World Health Organization. Coronavirus disease (COVID-19) advice for the public. www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public (accessed 20 March 2020).
375. World Health Organization. Getting your workplace ready for COVID-19. www.who.int/docs/default-source/coronaviruse/getting-workplace-ready-for-covid-19.pdf?sfvrsn=359a81e7_6 (accessed 20 March 2020).
376. World Health Organization. Coronavirus disease (COVID-19) technical guidance: infection prevention and control/WASH. www.who.int/emergencies/diseases/novel-coronavirus-2019/technical-guidance/infection-prevention-and-control (accessed 20 March 2020).
377. World Health Organization. Infection prevention and control during health care when coronavirus disease (‎COVID-19)‎ is suspected or confirmed. https://www.who.int/publications/i/item/WHO-2019-nCoV-IPC-2021.12021:accessed 26 November 2022.
378. World Health Organization. Coronavirus disease (COVID-19) pandemic. https://www.who.int/emergencies/diseases/novel-coronavirus-20192022:accessed 30 November 2022.
379. WillmottM, NicholsonA, BusseH, MacArthurGJ, BrookesS, CampbellR. Effectiveness of hand hygiene interventions in reducing illness absence among children in educational settings: a systematic review and meta-analysis. Archives of Disease in Childhood2016;101(1):42-50.10.1136/archdischild-2015-308875PMC471742926471110 doi:10.1136/archdischild-2015-308875 PubMed
380. WongVW, CowlingBJ, AielloAE. Hand hygiene and risk of influenza virus infections in the community: a systematic review and meta-analysis. Epidemiology and Infection2014;142(5):922-32.10.1017/S095026881400003XPMC489119724572643 doi:10.1017/S095026881400003X PubMed
381. WuS, WangY, JinX, TianJ, LiuJ, MaoY. Environmental contamination by SARS-CoV-2 in a designated hospital for coronavirus disease 2019. American Journal of Infection Control2020;48(8):910-4. [DOI: 10.1016/j.ajic.2020.05.003]PMC721432932407826 doi:10.1016/j.ajic.2020.05.003 PubMed
382. XiaoJ, ShiuEY, GaoH, WongJY, FongMW, RyuS, et al. Nonpharmaceutical measures for pandemic influenza in nonhealthcare settings - personal protective and environmental measures. Emerging Infectious Diseases2020;26(5):967-75. [DOI: 10.3201/eid2605.190994]PMC718193832027586 doi:10.3201/eid2605.190994 PubMed
383. ZivichPN, GanczAS, AielloAE. Effect of hand hygiene on infectious diseases in the office workplace: a systematic review. American Journal of Infection Control2018;46(4):448-55.10.1016/j.ajic.2017.10.00629195781 doi:10.1016/j.ajic.2017.10.006 PubMed
384. ZomerTP, ErasmusV, Van BeeckEF, Tjon-A-TsienA, RichardusJH, VoetenHA. Hand hygiene compliance and environmental determinants in child day care centers: an observational study. American Journal of Infection Control2013;41(6):497–502.10.1016/j.ajic.2012.06.00522959393 doi:10.1016/j.ajic.2012.06.005 PubMed
385. ZomerTP, ErasmusV, Van EmpelenP, LoomanC, Van BeeckEF, Tjon-A-TsienA, et al. Sociocognitive determinants of observed and self-reported compliance to hand hygiene guidelines in child day care centers. American Journal of Infection Control2013;41(10):862-7.10.1016/j.ajic.2012.11.02323510663 doi:10.1016/j.ajic.2012.11.023 PubMed
386. JeffersonT, FoxleeR, Del MarC, DooleyL, FerroniE, HewakB, et al. Interventions for the interruption or reduction of the spread of respiratory viruses. Cochrane Database of Systematic Reviews2006, Issue 6. Art. No: CD006207. [DOI: 10.1002/14651858.CD006207]17943895 doi:10.1002/14651858.CD006207 PubMed
387. JeffersonT, FoxleeR, Del MarC, DooleyL, FerroniE, HewakB, et al. Interventions for the interruption or reduction of the spread of respiratory viruses. Cochrane Database of Systematic Reviews2007, Issue 4. Art. No: CD006207. [DOI: 10.1002/14651858.CD006207.pub2]17943895 doi:10.1002/14651858.CD006207.pub2 PubMed
388. JeffersonT, Del MarC, DooleyL, FerroniE, Al-AnsaryLA, BawazeerGA, et al. Physical interventions to interrupt or reduce the spread of respiratory viruses: systematic review. BMJ2009;339:b.3657. [DOI: 10.1136/bmj.b367]PMC274916419773323 doi:10.1136/bmj.b367 PubMed
389. JeffersonT, Del MarC, DooleyL, FerroniE, Al-AnsaryLA, BawazeerGA, et al. Physical interventions to interrupt or reduce the spread of respiratory viruses. Cochrane Database of Systematic Reviews2010, Issue 1. Art. No: CD006207. [DOI: 10.1002/14651858.CD006207.pub3]20091588 doi:10.1002/14651858.CD006207.pub3 PubMed
390. JeffersonT, Del MarC, DooleyL, FerroniE, Al-AnsaryLA, BawazeerGA, et al. Physical interventions to interrupt or reduce the spread of respiratory viruses. Cochrane Database of Systematic Reviews2011, Issue 7. Art. No: CD006207. [DOI: 10.1002/14651858.CD006207.pub4]20091588 doi:10.1002/14651858.CD006207.pub4 PubMed
391. JeffersonT, Del MarCB, DooleyL, FerroniE, Al-AnsaryLA, BawazeerGA, et al. Physical interventions to interrupt or reduce the spread of respiratory viruses. Cochrane Database of Systematic Reviews2020, Issue 11. Art. No: CD006207. [DOI: 10.1002/14651858.CD006207.pub5]20091588 doi:10.1002/14651858.CD006207.pub5 PubMed