河北省2015-2016年诺如病毒感染性腹泻疫情的病原分子特征分析

Analysis of molecular characteristics of aggregation epidemic induced by norovirus infection in Hebei province, 2015-2016

目的 了解河北省诺如病毒（Norovirus,NoV）感染性腹泻疫情的病原流行特点及基因型变异情况.方法 收集2015年1月至2016年12月间,共8起感染性腹泻疫情临床标本和相关临床信息,采用实时荧光RT-PCR法检测NoV核酸,阳性标本经传统RT-PCR扩增衣壳蛋白区部分序列进行测序和系统进化分析.结果 河北省2015年1月至2016年12月间共发生8起腹泻疫情,病例265例,7起疫情中检测到NoV核酸阳性病例53例,检出率66.25％,罹患率波动在0.70％ ～8.13％,主要为小区居民、幼儿及学生.成功测序分型28份标本,基因型包括GⅠ.3型、GⅡ.2型、GⅡ.4型、GⅡ.13型和GⅡ.17型.结论 河北省NoV感染性腹泻疫情呈现病毒基因型多样性.

Objective To understand epidemiological characteristics of the pathogens and evolution of the genotype associated with infectious diarrhea epidemic caused by norovirus in Hebei Province.Methods A total of 8 infectious diarrhea outbreaks caused by norovirus were reported from Jan 2015 to Dec 2016,of which epidemic treatment materials and specimens were collected at the same time.Norovirus nucleic acid was detected by using real-time PCR,and the partial ORF2 of the all positive specimens were amplified by RT-PCR and sequenced.Phylogenetic tree was constructed by using MegaS.2 based on partial ORF2 sequences of norovirus to perform phylogenetic analysis.Results A total of 8 norovirus outbreaks,involving 265 cases who were mainly for residential inhabitents,children and students,were reported during this period,and the overall attack rate ranged from 0.70% to 8.13%.The overall positive detection rate of norovirus was 66.25%.The PCR products were sequenced,and sequencing result were obtained for 28 samples,which included G Ⅰ.3,GⅡ.2,GⅡ.4,GⅡ.13 and G]Ⅱ.17.Conclusions Multiple genotypes of infectious diarrhea outbreaks caused by norovirus were found in Hebei province.