Researchers at the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b) analyzed medical records collected between 2004 and 2014 through an urban surveillance system covering 5,500 children under five years of age. The surveillance operated in the Kamalapur study area of Dhaka, where field research assistants enrolled one child per household whenever the child met the inclusion criteria. Blood samples were collected for bacterial culture, and nasopharyngeal wash specimens were tested by reverse transcription polymerase chain reaction (RT-PCR) and tissue culture to identify viral pathogens. The team then mined this rich longitudinal dataset retrospectively, assembling case report forms into electronic records to characterize the epidemiology and etiology of otitis media in the cohort.

The findings confirm a considerable disease burden. Over the eleven-year study window, the database recorded 2,943 episodes of otitis media, yielding an overall prevalence of 7.7 percent among the children under surveillance. The mean age of affected children was 23.5 months, and 52.7 percent of cases were male. The burden was heavily concentrated in the youngest age group: children under one year of age accounted for 957 of the 2,943 episodes, or 32.5 percent, a rate far higher than their share of the population would predict. The mean duration of an episode was 10.3 days, and the researchers observed no difference in disease outcome between boys and girls, a statistical equivalence reflected in a p value of 0.208.

Seasonality emerged as a defining feature of the disease in this urban setting. The majority of otitis media visits occurred in spring, which accounted for 35.3 percent of episodes, followed closely by summer at 32.5 percent and fall at 32.2 percent. This clustering suggests that environmental and viral factors tied to particular times of year play an important role in triggering middle ear inflammation, a pattern consistent with the respiratory infection cycles seen in densely populated South Asian cities. Understanding these seasonal peaks, the authors note, could help clinicians and public health planners anticipate periods of highest risk and target preventive measures accordingly.

On the microbial side, the study provides unusually direct evidence of the pathogens circulating in children with otitis media. Blood cultures were positive among 2.4 percent of the children tested, and among the bacterial organisms identified in those positive cultures, Streptococcus pneumoniae comprised 5.7 percent. Taken together, Streptococcus species were detected in 8.6 percent of positive blood specimens. According to the authors, this was the first study to evaluate the pathogen in blood culture for this disease in the setting, a methodological distinction that matters because blood culture isolates offer a more specific indication of invasive bacterial infection than ear discharge or nasopharyngeal carriage alone.

Viral pathogens, by contrast, dominated the etiological picture. Viruses were identified among 18.8 percent of cases, and influenza virus was the most common, detected in 38.2 percent of the positive nasopharyngeal wash samples. The strong association between viral respiratory infections and otitis media is well established in the literature: viral infections of the upper airway impair Eustachian tube function, creating the negative pressure and fluid accumulation in the middle ear that define the disease, and they also facilitate bacterial growth by disrupting normal mucosal defenses. The prominence of influenza in this cohort underscores how heavily viral circulation shapes the otitis media burden in urban Bangladesh.

The clinical severity profile of the disease in this population was comparatively mild, a finding with important implications for health systems. No child was hospitalized primarily because of otitis media during the study period. Hospitalization did occur in 1 percent of cases, but only in the presence of comorbid conditions rather than as a direct consequence of the ear infection itself. This pattern suggests that while otitis media is extremely frequent in the community, most episodes resolve without invasive intervention, provided children have access to basic care. The authors caution, however, that the disease’s frequency combined with its hearing consequences makes it a substantial contributor to the overall burden of childhood morbidity even when individual episodes are not severe.

The study’s retrospective design and its reliance on records from a single urban surveillance site mean the findings should be interpreted with some care, and the authors acknowledge that further research is warranted to establish the current status of viral infections and otitis media in Bangladesh, given how strongly the two are linked. The dataset was originally assembled under two surveillance protocols, one investigating childhood pneumonia associated with Streptococcus pneumoniae and another monitoring influenza and the viral etiologies of influenza-like febrile illnesses in an urban slum of Dhaka, which explains why the team could draw on both blood culture and nasopharyngeal viral testing for their analysis. The Kamalapur field site, established through work connected to Johns Hopkins University and the Centers for Disease Control and Prevention, has long served as a platform for studying respiratory and enteric infections in Dhaka’s dense urban neighborhoods.

Perhaps the most actionable conclusion of the work concerns vaccination policy. The finding that influenza virus was the leading viral pathogen among children with otitis media, the authors argue, underscores the need to incorporate the influenza vaccine into Bangladesh’s national immunization schedule. They suggest that such an addition could serve as an effective strategy to prevent influenza-associated otitis media, reducing a substantial share of the disease burden in the youngest children. Bangladesh already includes the pneumococcal conjugate vaccine in its routine immunization program, which targets the leading bacterial cause identified in this and other studies, so adding influenza coverage would address the dominant viral driver as well.

For a disease that the World Health Organization has long recognized as a neglected contributor to childhood hearing loss and language delay, the new study fills an important gap in Asian data. It demonstrates that in an urban Bangladeshi cohort, otitis media affects roughly one child in thirteen under active surveillance, peaks in the first year of life, follows a clear seasonal rhythm, and is driven more by influenza and other respiratory viruses than by invasive bacteria in the community setting. As the authors conclude, the scarcity of comparable data across Asian countries, including Bangladesh, motivated the retrospective analysis in the first place, and their results now provide a benchmark against which future studies of otitis media epidemiology and etiology in the region can be measured.

Subject of Research: Epidemiology and etiology of otitis media in children under five in urban Bangladesh

Article Title: Epidemiology and etiology of otitis media among children under five years of age in an urban setting of Bangladesh

Article References: Sharmeen, A. T., Goswami, D., Nahar, K., Hossain, L., Rahman, M., & Zaman, K. (2026). Epidemiology and etiology of otitis media among children under five years of age in an urban setting of Bangladesh. BMC Pediatrics. https://doi.org/10.1186/s12887-026-07481-3

Image Credits: AI Generated

DOI: 10.1186/s12887-026-07481-3

Keywords: otitis media, children under five, Bangladesh, influenza, Streptococcus pneumoniae, pediatrics, hearing impairment, vaccination, epidemiology, viral infection, Dhaka, surveillance