2020—2021年咸阳市手足口病病原构成及柯萨奇病毒A6型序列分析  

Pathogen composition of Hand,Foot,and Mouth Disease and Sequence Analysis of Coxsackievirus A6 in Xianyang City,2020-2021

作　　者：王士峰 李珍妮 秦龙[1] 张俊君 WANG Shifeng;LI Zhenni;QIN Long;ZHANG Junjun(Xianyang Center for Disease Control and Prevention,Xianyang,Shaanxi 712000,China;不详)

机构地区：[1]咸阳市疾病预防控制中心,陕西咸阳712000 [2]西安市雁塔区疾病预防控制中心

出　　处：《中国预防医学杂志》2024年第6期763-769,共7页Chinese Preventive Medicine

摘　　要：目的了解咸阳市手足口病(hand,foot and mouth disease,HFMD)病原谱构成情况,分析柯萨奇病毒A6型(coxsackievirus A6,CVA6)VP1基因序列特征。方法对2020—2021年收集的HFMD病例样本进行反转录实时荧光定量聚合酶链式反应(reverse transcription real time PCR,RT-qPCR)检测分型,分析病原学监测结果;选取部分CVA6阳性样本,采用半巢式RT-PCR法扩增病毒VP1片段全长,扩增产物经测序后进行序列相似性和基因进化分析。结果2020—2021年共收集咸阳所辖县(区)HFMD样本615例,经RT-qPCR检测肠道病毒(enterovirus,EV)阳性率为72.20%(444/615)。其中CVA6样本占阳性样本总数的61.94%(275/444),其次是其他EV型22.07%(98/444)、CVA16型13.51%(60/444)、CVA10型2.48%(11/444)。2020年CVA6为主要流行毒株,2021年其他EV、CVA6与CVA16共同流行。EV阳性病例的发病时间在2021年呈双峰分布(5—7月为主高峰和9—11月为次高峰),2020年发病高峰为9—11月。秦都区、旬邑县和三原县EV阳性样本最多,总占比超过50%。与2008年芬兰株(KM114057)相比,本研究中的35条VP1序列核苷酸相似性为92.0%~94.4%,氨基酸序列相似性97.4%~98.7%,存在7个主要突变位点,其中A5T、S27N、V30A、S137N突变率接近100.00%。VP1基因进化分析显示,咸阳市2020—2021年CVA6型均属于D3a分支。结论2020—2021年咸阳市HFMD病原谱变化显著,CVA6为优势毒株,属于D3a基因亚型,需加强CVA6及其他EV分子病原学监测。Objective To characterize the pathogen composition of hand,foot,and mouth disease(HFMD)in Xianyang City and analyze the sequence characteristics of the viral protein 1(VP1)gene of Coxsackievirus A6(CVA6)positive specimens.Methods Reverse transcription real-time PCR(RT-qPCR)was used to detect and type the pathogens in HFMD samples collected in Xianyang City from 2020 to 2021.Partial CVA6-positive samples were selected,and the full-length VPl gene fragment was amplified by semi-nested RT-PCR.The amplified products were sequenced,and sequence similarity and phylogenetic analysis were performed.Results From 2020 to 2021,a total of 615 HFMD specimens were collected in Xianyang City,of which 444 were EV-positive by RT-qPCR,with a positive rate of 72.20%.The dominant pathogen was CVA6,accounting for 61.94%(275/444)of all positive samples,followed by other EV types(22.07%,98/444),CVA16(13.51%,60/444)and CVA10(2.48%,11/444).The main pathogen was CVA6 in 2020,while other EV,CVA6,and CVA16 were co-circulated serotypes in 2021.In this study,the distribution of EV positive cases in 2021 showed a biannual distribution,with one peak in May-July and another in September-November.However,there was only one peak(September-November)in 2020.More than half of the EV-positive specimens were collected in Qindu District,Xunyi County,and Sanyuan County.A total of 35 VP1 were amplified and sequenced.Compared with the 2008 Finland strain(KM114057),the nucleotide and amino acid sequence identities were 92.0%-94.4%and 97.4%-98.7%,and there were seven major mutation sites,among which the mutation rate of A5T,S27N,V30A,and S137N was close to 100.00%.Phylogenetic analysis of VP1 showed that CVA6 from 2020 to 2021 belonged to D3a branch.Conclusions The pathogenic spectrum of HFMD in Xianyang City changed significantly from 2020 to 2021,with CVA6 as the predominant strain,which belongs to the D3a sub-genotype.It is necessary to strengthen the surveillance for the molecular etiologyof CVA6and other EVs.

关 键 词：手足口病 病原谱 柯萨奇病毒A6型 VP1基因 

分 类 号：R181[医药卫生—流行病学]