ABSTRACT Human norovirus has been identified as a significant causative agent of acute gastroenteritis on a global scale. We investigated the epidemiological of norovirus infections in children with acute gastroenteritis in Shanghai between January 2022 and December 2024. The overall prevalence of norovirus was 13.22% (281/2126), with annual rates of 3.77% (20/531) in 2022, 18.30% (149/814) in 2023, and 14.34% (112/781) in 2024. The 281 norovirus strains were classified into the GI group (0.71%, 2/281) and GII group (99.29%, 279/281). Phylogenetic analysis revealed that 90.39% (254/281) of HuNoV strains were successfully genotyped for both VP1 and RdRp genes, with 15 distinct genotype combinations. The most prevalent strain was GII.4 SydneyP16 (52.36%, 133/254), followed by GII.17P17 (21.26%, 54/254) and GII.3P12 (11.42%, 29/254). Of note, GII.4 SydneyP16 was observed in both 2022 (56.25%, 9/16) and 2023 (74.10%, 103/139), while GII.17P17 emerged as the predominant genotype in 2024 (43.43%, 43/99). Furthermore, most of the GII.17P17 strains identified in 2024 clustered with GII.17P17 strains identified in the United States in 2025. These findings provide new insights into the genetic diversity of HuNoV and indicate a resurgence of a new GII.17P17, which has become a leading cause of sporadic AGE in children in Shanghai.
Lu et al. (Mon,) studied this question.