Laboratory-Based Surveillance and Genetic Diversity of Enteric Adenovirus Among Children in Argentina, 2022-2024

Enteric adenoviruses are recognized causes of pediatric acute gastroenteritis, yet national-level data on their epidemiology and genetic diversity in Argentina remain limited. This study aimed to describe the laboratory-based surveillance of enteric adenoviruses and to characterize the circulating genotypes among children during the 2022-2024 period. Data were obtained from the Argentine National Health Surveillance System, including weekly aggregated reports of adenovirus testing results from clinical laboratories nationwide. Detection frequencies were analyzed by year, age group, clinical setting, geographic region, and epidemiological week. Molecular characterization was performed using partial hexon gene sequencing. A total of 22,826 stool samples were tested, of which 1530 (6.7%) were positive for adenovirus, with no significant differences in positivity across years. Detection rates were highest among children under 1 year of age and were consistently greater in outpatient and emergency department settings compared with hospitalized patients. No clear seasonal pattern was observed. Genotyping revealed a predominance of HAdV-F41, with sporadic detection of non-enteric adenovirus types. These findings provide the first nationwide overview of enteric adenovirus circulation and genetic diversity in Argentina, highlighting stable transmission patterns and supporting the value of sustained laboratory surveillance to better characterize viral gastroenteritis etiology in the post-rotavirus vaccination era.