Emergence of human enteric adenovirus F41 among children with gastroenteritis in North-central Bangladesh, 2022-2024.

Human adenovirus F-41 (HAdV-F41) is an emerging cause of pediatric gastroenteritis, but data from South Asia remain limited. We investigated the molecular epidemiology, clinical features, seasonality of adenovirus-associated gastroenteritis and feasibility of an immunochromatography (IC) kit among children under 5 in north-central Bangladesh during July 2022-June 2024. Fecal samples from 360 children with acute gastroenteritis were tested for viral and bacterial pathogens using PCR, sequencing, and phylogenetic analyses. HAdV was detected in 7% (25/360) of cases, which was the second most common virus after rotavirus. Most adenovirus-positive samples (76%, 19/25) were adenovirus F-41. Infected children, aged 12-35 months, exhibited more severe gastrointestinal symptoms, including dehydration and severe vomiting. Infections peaked during colder months and were correlated with temperature. Study strains were closely related with contemporary global adenovirus F-41 strains. A rapid immunochromatographic assay for HAdV demonstrated high agreement with PCR. These findings identify adenovirus F-41 as an emerging contributor to pediatric gastroenteritis in Bangladesh and highlight the need for enhanced surveillance.