2021年河南省急性弛缓性麻痹病例中非脊髓灰质炎肠道病毒的分子鉴定

Molecular identification of non-polio enteroviruses in acute flaccid paralysis cases in Henan Province of China in 2021

目的探究2021年河南省急性弛缓性麻痹(acute flaccid paralysis,AFP)病例中非脊髓灰质炎肠道病毒(non-polio enterovirus,NPEV)的型别及流行特征。方法收集2021年河南省报告的529例AFP病例的粪便标本,对其进行病毒分离,其中NPEV阳性毒株进行VP1区域序列测定,使用MEGA5.1软件对序列进行比对并构建遗传进化树。使用Excel2016和SPSS26软件对流行病学数据进行整理和统计学分析。结果529例AFP病例粪便标本共分离出30株NPEV,分离率为5.67%(30/529),其中A组和B组病毒各分离出15株,未分离出C组和D组病毒。A组包含6个血清型,以柯萨奇病毒A组(coxsackievirus A,CVA)2型和CVA6为主,B组包含3个血清型,以柯萨奇病毒B组(coxsackievirus B,CVB)3型为主。人群分布中,5岁以内的儿童NPEV的分离率最高,为76.67%(23/30),男女比例为1.51∶1。地区分布中,A组病毒主要分布在河南省的中部、南部和西南部,以CVA2和CVA4分布最为广泛,B组病毒相对比较集中,主要分布在河南省的中部、北部和西南部,以CVB3为主。时间分布上全年除1~2月以外均能分离出NPEV,整体呈现春夏季高发,秋冬季低发的流行特征,其中A组病毒高峰期在5月份,B组病毒高峰期在6~7月。结论2021年河南省分离的NPEV以B组CVB3为主要血清型,NPEV的病原谱以及地区分布相比2018—2019年发生了显著变化,后期应当密切关注当前NPEV的流行趋势,为AFP的诊断、监测以及维持河南省无脊髓灰质炎的状态提供理论依据。

Objective To investigate the serotypes and epidemic characteristics of non-polio enteroviruses(NPEV)in acute flaccid paralysis(AFP)cases in Henan Province in 2021.Methods Fecal specimens of 529 AFP cases reported in Henan Province in 2021 were collected for virus isolation.The VP1 regions of NPEV were sequenced.MEGA5.1 software was used for sequence alignment and a phylogenetic tree was constructed as well.The epidemiological data were organized and statistically analyzed using Excel2016 and SPSS26 software.Results A total of 30 strains of NPEV were isolated from the fecal specimens of 529 AFP cases,with an isolation rate of 5.67%(30/529).They were belonged to group A and group B with 15 strains in each group,and no group C or group D viruses were isolated.Group A contained six serotypes and was dominated by coxsackievirus A2(CVA2)and CVA6.Group B contained tree serotypes and was dominated by CVB3.In the population distribution,the separation rate of NPEV was the highest among children under 5 years old,which was 76.67%(23/30),and the ratio of male to female was 1.51∶1.In the regional distribution,group A viruses were mainly distributed in the central,southern and southwestern parts of Henan Province with CVA2 and CVA4 being the most widely distributed,while group B viruses were relatively concentrated,mainly distributed in the central,northern and southwestern parts of Henan Province with CVB3 being the predominant.In terms of time distribution,NPEV could be isolated throughout the year except from January to February,showing the epidemic characteristics of high incidence in spring and summer and low incidence in autumn and winter.The peak of group A virus infection was in May and the peak period of group B virus infection was from June to July.Conclusions CVB3 was the main serotype of NPEV isolated in Henan Province in 2021.The pathogenic spectrum and regional distribution of NPEV had changed significantly compared with those in 2018-2019.In order to provide reference for the diagnosis and surveillance of AFP and maintain the polio-free status in Henan Province,much attention should be paid to the current epidemic trend of NPEV.