Epidemiology and genetic diversity of norovirus GII genogroups among pediatric patients in Beijing, China, during 2023–2024
Junhong Ai, Qiliang Li, Ke Xu, Yuxuan Li, Ying Liu, Luci Huang, Wenqi Song, Zhengde Xie
Abstract
BACKGROUND: Norovirus is an important cause of viral acute gastroenteritis (AGE) worldwide. METHODS: In order to characterize the molecular epidemiology and genetic diversity of norovirus in children in Beijing, 3634 anal swab samples of AGE patients from January 2023 to December 2024 were analyzed. Norovirus was detected using RT-PCR and genotyped by sequencing the partial RdRp and VP1 region. RESULTS: During the two-year period, norovirus was detected in 19.6% of AGE cases, with the highest detection rate in children under 3 years of age. GII.4 and GII.P16 were the dominant genotypes of VP1 and RdRp, with a detection rate of 36.39% and 44.59%, respectively. According to the dual-typing system combined the RdRp and VP1, the dominant genotypes of norovirus changed between 2023 and 2024. In 2023, the most common genotype was GII.3[P12] (39.15%), followed by GII.4 Sydney[P16] (32.34%) and GII.4 Sydney[P31] (15.32%). However, in 2024, the dominant genotype was GII.17[P17] (41.43%), followed by GII.4 Sydney[P16] (34.29%) and GII.3[P12] (20.0%). The GII.17 variants in this study were divided into two clusters: cluster IIIa and IIIb, which shared high nucleotide identity with GII.17 variant emerged in 2014/2015. Significantly, GII.4 Sydney[P31] and novel GII.4 Sydney[P16] variants co-circulating in this region from 2023 to 2024. CONCLUSION: The data provided useful information on the molecular epidemiology of norovirus in sporadic AGE among children and highlighted the necessary to continuously monitor the epidemiological characteristics of norovirus associated AGE.