Epidemiological characteristics of rotavirus among children aged 5 years and under in Zhangzhou, China, 2023–2024

OBJECTIVES: To investigate the molecular epidemiology of Rotavirus alphagastroenteritidis (RVA) among children with acute gastroenteritis (AGE) in Zhangzhou, China, during 2023-2024. METHODS: Stool samples were collected from children diagnosed with AGE and were screened for RVA presence using immunochromatography. The partial VP4 and VP7 genes of RVA-positive samples were amplified and sequenced for phylogenetic analysis. RESULTS: RVA was detected in 10.98% (202/1839) of the samples. Notably, the highest positivity rate was observed in children aged 4-5 years. Among 202 RVA-positive samples, 8 different RVA genotypes were detected with different frequencies. Overall, G8P[8] (62.02%) was the most common RVA genotype, followed by G1P[8] (16.28%), G3P[8] (14.73%) and G9P[8] (13.18%). Phylogenetic analysis of the VP7 gene demonstrated that the G8 strains were clustered within G8-Ⅵ lineage, exhibiting close genetic similarity to contemporary strains circulating in Japan and Southeast Asia. Simultaneously, the VP4 gene of all P[8] strains was classified within the P[8]- Ⅲ lineage, which is distinct from P[8] lineages found in currently licensed RVA vaccines. CONCLUSIONS: This study provides the first documented evidence of the predominance of the G8P[8] genotype in Zhangzhou, suggesting its emergence as the dominant genotype within this population. The findings underscore the dynamic evolutionary patterns of RVA in the region and highlight the urgent necessity for ongoing molecular surveillance. Such efforts are essential to monitor emerging strains, assess potential vaccine mismatches, and guide future immunization strategies.