Epidemiological characteristics of outbreaks of norovirus GII.17P17 acute gastroenteritis in China, 2022
10.3760/cma.j.cn112866-20231008-00040
- VernacularTitle:2022年我国GII.17[P17]诺如病毒急性胃肠炎暴发流行病学特征
- Author:
Yanhui YANG
1
;
Xiangyu KONG
;
Qing ZHANG
;
Lijiao CAO
;
Shi CONG
;
Jingxin LI
;
Miao JIN
;
Zhaojun DUAN
Author Information
1. 传染病溯源预警与智能决策全国重点实验室 卫生部医学病毒和病毒病重点实验室 中国疾病预防控制中心病毒病预防控制所，北京 102206
- Keywords:
Norovirus;
Acute gastroenteritis;
Outbreak;
Genotype
- From:
Chinese Journal of Experimental and Clinical Virology
2024;38(1):58-66
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To analyze the epidemiological characteristics of norovirus (NoV) acute gastroenteritis (AGE) outbreaks caused by GII.17[P17] variant in China, 2022.Methods:Information and specimens of AGE outbreaks between January and December 2022 were collected. NoV RNA was detected in all specimens by real-time RT-PCR. The viral genome of the positive specimens were amplified, sequenced and analyzed.Results:Between January and December 2022, 360 AGE outbreaks were reported cumulatively, of which 266 outbreaks successfully obtained genotype results. GII.17 [P17] was one of the main genotypes and detected in 34 outbreaks (12.78%, 34/266), with the highest number of outbreaks detected in spring (6 outbreaks in March and 7 outbreaks in May), mainly in childcare facilities and primary schools (61.76%, 21/34). According to the result of NoV genotype analysis in different age groups, 14 strains of GII.17 [P17] in this study belonged to Cluster III b and SC III branch of Cluster III (Kawasaki308) in the capsid region and polymerase region, respectively, and both belonged to the same cluster as the variant strain (GZ41621 strain) that caused the NoV AGE outbreaks in China during the 2014/15 season. Compared to reference strains of Cluster I, Cluster II and Cluster III a, Cluster III b was provided with 22 amino acid mutations in VP1. The main amino acid changes in the subgroup of Cluster III b including the virus strains isolated in this study were at T294I and Q299R of antigen epitope A, an insertion mutation occurred at antigen epitope D, H353Q at the site I of the human histo-blood group antigen receptor binding site. The selection pressure analysis detected a large number of negative selection sites, indicating that negative selection plays an important role in the evolution of VP1 genes.Conclusions:GII.17 [P17] was one of the primary genotypes responsible for NoV diarrhea outbreaks in China in 2022. Phylogenetic analysis had revealed that it still belonged to the same cluster as the novel GII.17 [P17] variant (strain GZ41621) that caused NoV epidemics in China during the 2014/15 season, exhibiting minor amino acid variations at the potential epitope.
