2017-2022年淄博市诺如病毒流行特征及病原学基因分析

Epidemiological characteristics and pathogenic gene analysis of Norovirus in Zibo City from 2017 to 2022

目的分析2017-2022年淄博市诺如病毒感染性疫情流行特征及优势基因型,为诺如病毒感染防控提供科学依据。方法用描述性流行病学方法,对2017-2022年淄博市诺如病毒感染性疫情流行病学资料和实验室检测资料进行统计分析。结果2017-2022年淄博市共报告35起诺如病毒感染性疫情,其中托幼机构23起,中学7起,餐饮机构3起,小学和养老机构各1起,不同场所罹患率有统计学意义;报告发病917人,罹患率为8.30%,疫情总体呈上升趋势,年均增长率为10.76%;城市29起,农村6起,罹患率城市高于农村,差异有统计学意义;85.71%的诺如病毒感染性疫情与人传人传播有关,每年10月至次年3月是诺如病毒感染性疫情高峰期(68.57%,24/35);35起疫情中,以诺如病毒GⅡ组为主(阳性率80.00%,176/220),GI组检出率为13.641%(30/220),GⅨ组检出率低(6.36%,14/220);基因分型GⅡ.2[P16]占比最高(占35.71%,10/28),其次GⅡ.4[P16](占14.29%,4/28)、GⅡ.3[P12](占10.71%,3/28)和少数其他重组基因型。结论淄博市诺如病毒感染性疫情呈现上升趋势,托幼机构是发生诺如病毒感染性疫情的主要场所,诺如病毒感染性疫情主要为GⅡ组为主,GⅡ.2[P16]基因型为优势基因型,合并多种重组型的流行特征,加强诺如病毒分子流行病学监测,有利于掌握诺如病毒流行病学特征,为科学防控提供理论依据。

Objective To analyze the epidemiological characteristics and the predominant genotypes of Norovirus infection in Zibo city from 2017 to 2022,so as to provide scientific basis for prevention and control of Norovirus infection.Methods Descriptive epidemiological methods were used to analyze the epidemiological data and the laboratory data of Norovirus infection in Zibo city from 2017 to 2022.Results From 2017 to 2022,a total of 35 Norovirus outbreaks were reported in Zibo,including 23 in nursery institutions,7 in middle schools,3 in catering institutions,and 1 each in primary schools and elderly care institutions.The differences of attack rates in different places were statistically significant.917 cases were reported,with an incidence rate of 8.30%.The overall trend of the epidemic was on the rise,with an average annual growth rate of 10.76%.There were 29 outbreaks in urban areas and 6 in rural areas.The attack rate was higher in urban areas than that in rural areas,and the difference was statistically significant.85.71%of Norovirus infection outbreaks were related to person-to-person transmission,and the peak period for Norovirus infection was from October to March of the following year(68.57%,24/35).Among the 35 outbreaks,the GII group was the most predominant genotype(positive rate 80.00%,176/220),with a detection rate of 13.641%(30/220)for the GI group,and a low detection rate of 6.36%(14/220)for the GIX group.The genotype GII.2[P16]had the highest proportion(35.71%,10/28),followed by GII.4[P16](14.29%,4/28),GII.3[P12](10.71%,3/28),and a few other recombinant genotypes.Conclusion The Norovirus infection outbreaks in Zibo city showed an increasing trend,and nursery institutions were the main places where Norovirus infection occured.The Norovirus infections were mainly caused by GII,and the GII.2[P16]was the predominant genotype,with the epidemic of multiple recombinant genotypes.Strengthening molecular epidemiological surveillance is helpful for understanding the epidemiological characteristics of Norovirus and providing theoretical basis for scientific prevention and control.