Emerging Trend of Notably High Prevalence of Human Enteric Adenovirus F41 Among Pediatric Patients With Acute Gastroenteritis in Thailand, 2022-2024.

Human adenovirus (HAdV) is one of the causative viral pathogens of acute gastroenteritis (AGE) in children worldwide, accounting for approximately 10% of diarrheal cases. To enhance understanding of the prevalence and epidemiology of HAdV infection, we conducted a 3-year molecular detection and characterization study of HAdV associated with AGE in Chiang Mai, Thailand, from 2022 to 2024. Among 1356 pediatric patients, HAdV was detected in 85 cases (6.3%). The highest HAdV infection rate was observed in 2023 (10.4%). HAdV infections were most frequently detected in children aged 3-4 years. Co-circulation of three HAdV species, including enteric HAdV-F and non-enteric HAdV-B and HAdV-C, was detected. Among these, six genotypes were identified, including HAdV-F41 (44.7%), HAdV-B3 (18.8%), HAdV-C1 (17.6%), HAdV-C5 (11.8%), HAdV-C2 (5.9%), and HAdV-B7 (1.2%). Notably, the emergence of HAdV-F41 was observed in 2023, accounting for 65.2% of HAdV-positive cases in that year. HAdV infections occurred year-round, with higher detection rates observed in June and August of 2023. In conclusion, this study demonstrates the prevalence, seasonality, and genotype diversity of HAdV infections among children with AGE in Thailand during 2022-2024. These findings indicate the co-circulation of enteric and non-enteric HAdVs in pediatric patients with AGE and provide valuable epidemiological insights for future surveillance and prevention strategies.