扬州市2017—2021年诺如病毒感染疫情流行特征分析

Analysis of epidemiological characteristics of Norovirus infection epidemic in Yangzhou City from 2017 to 2021

目的分析扬州市2017—2021年诺如病毒感染疫情的流行特征,为制定预防控制措施提供依据。方法收集2017—2021年扬州市诺如病毒感染疫情资料,采用描述性流行病学方法描述其流行病学特征,并进行相关因素统计学分析。结果2017—2021年扬州市共报告诺如病毒感染疫情43起,发病例数的中位数为21例。2017、2018和2021年疫情发生较多,冬春季节高发,多发于城区小学,发病例数为1995例,平均罹患率为2.86%;首发病例发病时间至疫情发现时间与疫情持续时间(r=0.618,P=0.002)、疫情累计发病例数(r=0.605,P=0.002)呈正相关。基因型以GⅡ型为主,占90.70%,其次为GⅠ型。隐性感染率为15.09%(8/53),隐性感染率在性别(χ^(2)=1.876,P=0.171)、年龄(t=0.249,P=0.804)、病毒型别(χ^(2)=0.513,P=0.474)差异均无统计学意义。结论2017—2021年扬州市诺如病毒感染疫情多发于冬春季节,及早发现上报疫情及采取疫情处置措施可有效减少疫情的扩散传播。

Objective To analyze the epidemiological characteristics of Norovirus infection epidemic in Yangzhou City from 2017 to 2021,and provide a basis for formulating prevention and control measures.Methods The epidemiological data of Norovirus infection epidemic in Yangzhou City from 2017 to 2021 were collected,descriptive epidemiological methods were used to describe its epidemiological characteristics,and the related factors were statistically analyzed.Results From 2017 to 2021,a total of 43 Norovirus infection outbreak epidemics were reported in Yangzhou City,the median number of incidence cases was 21.In 2017,2018 and 2021,there were many outbreak epidemics,which mainly occurred in winter and spring,and most of the epidemics occurred in urban primary schools.The number of incidence cases was 1995,with an average attack rate of 2.86%.The time from the onset of the first case to the discovery of the epidemic was positively correlated with the duration(r=0.618,P=0.002)and the cumulative number of cases(r=0.605,P=0.002)of the epidemic.The genotype was mainly GⅡtype(90.70%),followed by GⅠtype.The inapparent infection rate was 15.09%(8/53),and there was no statistically significant difference in the inapparent infection rate among gender(χ^(2)=1.876,P=0.171),age(t=0.249,P=0.804),and virus type(χ^(2)=0.513,P=0.474).Conclusion The Norovirus infection epidemics in Yangzhou City mostly occur in winter and spring from 2017 to 2021.Early detection and reporting of the epidemic and the adoption of epidemic management measures can effectively reduce the spread of the epidemic.