临沂市病毒性腹泻诺如病毒感染流行病学及病原学特征分析

Epidemiological and pathogenic characteristics of norovirus infection in viral diarrhea in Linyi city

目的分析2017-2018年山东省临沂市病毒性腹泻诺如病毒感染的流行病学和病原学特征,探讨流行规律、为防控提供依据。方法按照监测方案要求,收集病毒性腹泻监测病例信息,并对采集的标本开展诺如病毒核酸检测和基因分型,采用描述流行病学方法分析数据。结果采集报告的1 125例病毒性腹泻病例粪便标本并检测病毒核酸,其中诺如病毒阳性160份、阳性率14.22%,均为GⅡ型;阳性率2017年为15.50%、2018年为13.26%,差异无统计学意义(χ^2=1.13,P=0.29);男性病人661例、阳性率13.77%,女性病人464例、阳性率14.87%,男女阳性率差异无统计学意义(χ^2=0.27,P=0.60);0~80岁各年龄组均检出诺如病毒核酸,其中5岁及下年龄组阳性率最高(18.35%);感染冬春季高发,阳性率最高的县(区)为沂南县(30.65%)、最低的为郯城县(2.56%)。结论临沂市病毒性腹泻诺如病毒感染以GⅡ型为主,冬春季节高发,以儿童感染为主;应进一步开展毒株基因分型、探讨流行特征,有针对性地开展防控工作。

Objective To analyze the epidemiological and pathogenic characteristics of viral diarrhea infection with norovirus in Linyi city from 2017 to 2018, discuss the epidemic rules, and provide basis for the prevention and control.Methods According to the requirements of the surveillance program, the information and samples of viral diarrhea cases were collected, and the nucleic acid and genotype of norovirus were detected. Descriptive epidemiological methods were taken for data analysis. Results The feces samples of the reported 1 125 cases of viral diarrhea were collected to detect nucleic acid, including 160 samples of norovirus positive of GⅡ type, with positive rate of 14.22%. The positive rate was15.50% in 2017 and 13.26% in 2018, without statistical difference(χ^2=1.13, P=0.29). There were 661 cases of the male and464 of the female, with the positive rate of 13.77% and 14.87%, respectively, and without statistical difference(χ^2=0.27, P=0.60). Norovirus was detected in all age groups from 0 to 80 years, with the highest positive rate(18.35%) in age groups of 5 years and younger. Norovirus infection was much more in winter and spring. The positive rate was the highest in Yinan county(30.65%) and lowest in Tancheng county(2.56%). Conclusions The viral diarrhea cases infected with norovirus are genotype G Ⅱ in Linyi city, and much more in winter and spring, and children infection is the dominant. Gene typing and epidemic features exploring should be conducted further for prevention and control.