Norovirus infection in pediatric acute gastroenteritis: epidemiology and clinical features in Ezhou, China, 2023–2025

Abstract

Objective Norovirus (NoV) is a major pathogen causing acute gastroenteritis (AGE) worldwide, imposing a substantial disease burden. This study aimed to investigate the epidemiological, clinical and genotypic characteristics of NoV infection in pediatric patients with AGE in Ezhou, central China. Methods Between January 2023 and June 2025, we enrolled pediatric AGE patients from Ezhou Maternal and Child Health Hospital and collected their demographic profiles, clinical records and stool specimens, together with matched local meteorological data. All stool samples were screened for NoV using a commercial colloidal gold immunoassay kit. A randomly selected subset of NoV−positive samples was further subjected to genetic sequencing. Results Among the 8,435 enrolled pediatric patients, 422 (5.0%) tested positive for NoV, with annual positivity rates of 4.24% (2023), 5.89% (2024), and 4.57% (January-June 2025). The positive cases comprised 259 males and 163 females. Children aged 1–2 years had the highest NoV positivity rate. The epidemic period spanned winter to spring, corresponding to ambient humidity of 66.5%–69.95%. Typical clinical presentations included fever, vomiting, watery diarrhea, dehydration, abdominal pain, convulsions, lethargy and electrolyte disturbances. Genetic sequencing identified three NoV genotypes across the 2.5-year surveillance period: GII.17, GII.3 and GII.4. Conclusions NoV infection prevalence rose continuously in Ezhou during the 2.5-year study period, with seasonal peaks in winter and spring. GII.17 was the dominant genotype among sequenced isolates. Children aged 1–2 years constitute the highest-risk population and exhibit a wide range of clinical manifestations. Fecal colloidal gold immunoassay serves as a practical screening tool for NoV detection in pediatric populations at primary medical institutions.