[Genotyping analysis of norovirus infectious diarrhea clusters in Songjiang district, Shanghai from 2017 to 2019].

Objective: We aimed to analyze the the genotyping of norovirus infectious diarrhea epidemic in Songjiang district, Shanghai, and explored the experience in handling the epidemic to provide a scientific basis for formulating prevention and treatment strategies. Methods: The epidemiological data and related samples of 69 outbreaks of infectious diarrhea caused by norovirus was collected from 2017 to 2019 in Songjiang district, Shanghai. Sequencing and type identification were performed by the method of gene sequencing for the junction region of Norovirus ORF1 and ORF2. Results: From 2017 to 2019, 69 outbreaks of norovirus infections diarrhea were reported in Songjiang district, Shanghai. A total of 1 767 samples were tested, including 619 case samples (positive rate 19.9%), 343 practitioner samples (positive rate 1.1%), 505 environmental samples (positive rate 0.5%) and 300 food samples (not detected). 141 sequences were obtained, and the genotype analysis showed that the genotype that mainly caused infectious diarrhea in 2017 and 2018 was GII.P16-GII.2 (50.98%, 26/51). In 2019, the genotypes that mainly caused infectious diarrhea were GII.P16-GII.2 (13.73%, 7/51) and GII.Pe-GII.4 (9.80%, 5/51). Conclusion: The main genotype of the 69 outbreaks of nororirus infectious diarrhea epidemic in Songjiang district, Shanghai from 2017 to 2019 was GII.P16-GII.2, which showed obvious peaks in spring, autumn and winter. There were more infections in kindergartens and schools. The surveillance of norovirus infection should be strengthened.目的： 了解2017—2019年上海市松江区诺如病毒感染性腹泻疫情病毒基因型特征。 方法： 收集上海市松江区2017—2019年69起由诺如病毒引起的感染性腹泻疫情的流行病学资料及相关样本，用针对诺如病毒ORF1和ORF2连接区进行基因测序的方法进行诺如病毒基因测序及型别鉴定。 结果： 2017—2019年，上海市松江区共报告诺如病毒感染腹泻疫情69起，共检测1 767份样本：619份病例样本（诺如病毒阳性率19.9%），343份从业人员样本（诺如病毒阳性率1.1%），505份环境样本（诺如病毒阳性率0.5%）和300份食品样本（未检出）。测序获得141株基因序列，基因型别分析显示2017年和2018年主要引起感染性腹泻的基因型别为GII.P16-GII.2（50.98%，26/51），而2019年引起感染性腹泻的基因型别中GII.P16-GII.2（13.73%，7/51）和GII.Pe-GII.4（9.80%，5/51）较多。 结论： 引起上海市松江区2017—2019年诺如病毒感染的69起腹泻疫情病毒主要的基因型别为GII.P16-GII.2，呈明显的春、秋冬季高峰，且幼儿园及学校的事件较多。.