Beyond Rotavirus: Seasonal Dynamics and Genetic Diversity of Non-Polio Enteroviruses in Hospitalized Children with Acute Gastroenteritis in Pune, India

Background: Acute gastroenteritis (AGE) in children is primarily associated with pathogens such as Rotavirus, Norovirus, Adenovirus, Astrovirus, and increasingly, human enteroviruses (EVs). EVs are non-enveloped RNA viruses belonging to the Picornaviridae family, comprising over 100 subtypes classified into four species. Despite their clinical relevance, the prevalence of EVs in AGE remains underexplored in India, resulting in limited data on their epidemiology and molecular diversity. Methods: A total of 450 stool samples were collected from hospitalized children under five years of age with AGE in Pune, India, between 2017 and 2023. Molecular characterization was subsequently performed to identify and confirm the types of enteroviruses present. Results: EVs were detected in 11.3% (51/450) of cases; 58.8% (30/51) among them were mono-infections. Rotavirus emerged as the most frequently identified pathogen, while co-infections involving Norovirus, Adenovirus, Astrovirus, and Parechovirus were documented. Eighteen distinct EV genotypes were characterized, with EV-B being the most dominant (64%). EVs were found circulating throughout the year, with a notable peak in the monsoon (June-August), and were predominantly detected in children below two years of age. Conclusion: Association of EVs in more than 10% of AGE cases highlights the importance of incorporating EV screening in AGE cases and understanding the burden caused by this important group of viruses.