Otitis

BackgroundUpper respiratory infections (URIs) are the leading cause of acute disease incidence worldwide and contribute to a substantial health-care burden. Although acute otitis media is a common complication of URIs, the combined global burden of URIs and otitis media has not been studied comprehensively. We used results from the Global Burden of Diseases, Injuries, and Risk Factors Study 2021 to explore the fatal and non-fatal burden of the two diseases across all age groups, including a granular analysis of children younger than 5 years, in 204 countries and territories from 1990 to 2021.MethodsMortality due to URIs and otitis media was estimated with use of vital registration and sample-based vital registration data, which are used as inputs to the Cause of Death Ensemble model to separately model URIs and otitis media mortality by age and sex. Morbidity was modelled with a Bayesian meta-regression tool using data from published studies identified via systematic reviews, population-based survey data, and cause-specific URI and otitis media mortality estimates. Additionally, we assessed and compared the burden of otitis media as it relates to URIs and examined the collective burden and contributing risk factors of both diseases.FindingsThe global number of new episodes of URIs was 12·8 billion (95% uncertainty interval 11·4 to 14·5) for all ages across males and females in 2021. The global all-age incidence rate of URIs decreased by 10·1% (-12·0 to -8·1) from 1990 to 2019. From 2019 to 2021, the global all-age incidence rate fell by 0·5% (-0·8 to -0·1). Globally, the incidence rate of URIs was 162 484·8 per 100 000 population (144 834·0 to 183 289·4) in 2021, a decrease of 10·5% (-12·4 to -8·4) from 1990, when the incidence rate was 181 552·5 per 100 000 population (160 827·4 to 206 214·7). The highest incidence rates of URIs were seen in children younger than 2 years in 2021, and the largest number of episodes was in children aged 5-9 years. The number of new episodes of otitis media globally for all ages was 391 million (292 to 525) in 2021. The global incidence rate of otitis media was 4958·9 per 100 000 (3705·4 to 6658·6) in 2021, a decrease of 16·3% (-18·1 to -14·0) from 1990, when the incidence rate was 5925·5 per 100 000 (4371·8 to 8097·9). The incidence rate of otitis media in 2021 was highest in children younger than 2 years, and the largest number of episodes was in children aged 2-4 years. The mortality rate of URIs in 2021 was 0·2 per 100 000 (0·1 to 0·5), a decrease of 64·2% (-84·6 to -43·4) from 1990, when the mortality rate was 0·7 per 100 000 (0·2 to 1·1). In both 1990 and 2021, the mortality rate of otitis media was less than 0·1 per 100 000. Together, the combined burden accounted for by URIs and otitis media in 2021 was 6·86 million (4·24 to 10·4) years lived with disability and 8·16 million (4·99 to 12·0) disability-adjusted life-years (DALYs) for all ages across males and females. Globally, the all-age DALY rate of URIs and otitis media combined in 2021 was 103 per 100 000 (63 to 152). Infants aged 1-5 months had the highest combined DALY rate in 2021 (647 per 100 000 [189 to 1412]), followed by early neonates (aged 0-6 days; 582 per 100 000 [176 to 1297]) and late neonates (aged 7-24 days; 482 per 100 000 [161 to 1052]).InterpretationThe findings of this study highlight the widespread burden posed by URIs and otitis media across all age groups and both sexes. There is a continued need for surveillance, prevention, and management to better understand and reduce the burden associated with URIs and otitis media, and research is needed to assess their impacts on individuals, communities, economies, and health-care systems worldwide.FundingBill & Melinda Gates Foundation.

PurposeCommon respiratory infections were significantly reduced during the COVID-19 pandemic due to general protective and hygiene measures. The gradual withdrawal of these non-pharmaceutical interventions (NPI) was associated with a notable increase in these infections, particularly in pediatric and adult otorhinolaryngology. The aim of this retrospective monocentric study was to evaluate the impact of NPI during the COVID-19 pandemic on the incidence and severity of acute mastoiditis (AM).MethodsPre-pandemic clinical data of AM cases from 2011 to 2019 were compared with infection counts from January 2020 to June 2023 for seasonal periodicity, age-specific differences, pathogens, and complication rates in a German third-level hospital.ResultsOut of 196 patients with AM 133 were children, the majority between 1 and 5 years of age. Complications of AM, such as meningitis, brain abscess, and sinus vein thrombosis, were more common in adults (87%) than in children (17%). Morbidity and mortality rates were similar before, during and after the pandemic. Pneumococci were the most common pathogen in both age groups, with a post-pandemic cumulation of Streptococcus pyogenes infections in children. While pre-pandemic cases clustered in spring, seasonality was absent in all age groups during the main phase of the pandemic. The cessation of NPI caused a steep rise in AM cases in both age groups starting from December 2022.ConclusionNPI during the COVID-19 pandemic reduced the incidence of AM. Their reversal led to a substantial increase in the incidence of AM during the post-pandemic period, which may be due to a general increase in viral respiratory infections and an insufficiently trained immune system.

The activation of the NLRP3 inflammasome has been linked to several inflammatory and autoinflammatory diseases. Despite cases of potential hearing improvement in immune-mediated diseases, direct evidence of the efficacy of targeting this mechanism in the inner ear is still lacking. Previously, we discovered that macrophages are associated with Sensorineural Hearing loss (SNHL) in Chronic Suppurative Otitis Media (CSOM), the leading cause of this permanent hearing loss in the developing world and incurring costs of $4 to $11 billion dollars in the United States. However, the underlying mechanism remained unknown. Here, we investigate how macrophages drive permanent hearing loss in CSOM. We first confirmed the occurrence of NLRP3 inflammasome activation in cochlear macrophages in CSOM. We then revealed that Outer Hair Cells (OHCs) were protected in CSOM by macrophage depletion and subsequently confirmed the same protection in the NLRP3 knockout condition. Furthermore, we showed that therapeutic inhibition of NLRP3 inflammasome activation and downstream inhibition of IL-1β protects OHCs in CSOM. Collectively, our data demonstrates that the main driver for hearing loss in CSOM is NLRP3 inflammasome activation in cochlear macrophages and this is therapeutically targetable, leading the way for the development of interventions to prevent the leading cause of permanent hearing loss and a costly disease in the developed world.

This article describes the microbiome of the outer ear and the earwax in the ear canal, which performs various protective functions against bacterial infections. This article is based on an analysis of literature gathered from databases including PubMed, Google Scholar, Web of Science, and Scopus, primarily from the last 15 years. The search strategy included MeSH terms: ear canal, microbiome, earwax, cerumen, antibacterial peptides, ear infections, biofilm. Only peer-reviewed articles were included. The natural ear canal microbiota provides so-called colonization resistance, which protects against invasion by pathogenic microorganisms. Earwax is composed primarily of keratin secreted by epithelial cells and substances secreted by sweat and apocrine glands. It plays a key role in the physiology of the ear canal, maintaining a low pH, limiting moisture, and exhibiting antimicrobial properties. Both an excess and a deficiency of earwax can lead to dysbiosis of the outer ear, and consequently to the development of various infections. In an era of increasing antibiotic resistance and the search for new solutions in the fight against pathogenic microorganisms, understanding the natural properties of earwax is becoming increasingly important.