Asymptomatic Shedding of Enteric Viruses in Young Children: Insights From a Year-Long Prospective Surveillance Study.

Enteric viruses are a leading cause of gastroenteritis in young children. With the increasing use of multiplex PCR, these viruses are frequently detected in asymptomatic children. In this prospective study conducted from March 2024 to February 2025, rectal swabs were collected from children < 5 years with no history of diarrhea or vomiting in the preceding month and no fever in the prior week. Samples were tested for rotavirus, norovirus, adenovirus, astrovirus, and sapovirus. Parental questionnaires and follow-up interviews assessed risk factors and monitored symptom development. Enteric viruses were detected in 17.6% of asymptomatic children, most commonly rotavirus (6.2%) and norovirus (5.1%). Detection peaked during the second year of life. No differences were observed in daycare attendance, number of siblings, or underlying conditions between virus-positive and virus-negative asymptomatic children. Breastfeeding was significantly protective (OR 0.19, 95% CI 0.06-0.51), while recent antibiotic use was more common in virus-positive cases. Compared with symptomatic children tested during the same period, asymptomatic children had significantly higher cycle threshold (Ct) values, except for astrovirus. Seasonal distribution of viruses was similar across both groups. These findings suggest that asymptomatic children may contribute to viral transmission and that Ct PCR results, alongside clinical context, may aid result interpretation.