昆明市手足口病病原构成及柯萨奇病毒A组6型基因特征分析(2016-2018年)

Pathogenic spectrum of hand,foot and mouth disease and the genetic characteristics of coxsackievirus A6 in Kunming,2016-2018

目的了解2016-2018年昆明市手足口病病原构成情况,阐明昆明市流行的柯萨奇病毒A组6型(CV-A6)基因特征。方法对2016-2018年云南省手足口病实验室监测系统收集的昆明市手足口病患儿样本使用CV-A16和肠道病毒71型(EV-A71)+EV通用型核酸检测试剂盒进行实时荧光RT-PCR检测,并对非EV-A71和非CV-A16阳性样本进行普通RT-PCR扩增得到VP1全长序列。用MEGA 5.2软件对本次研究分离到的昆明市CV-A6毒株序列与参考序列构建系统进化树,分析其分子流行病学特征。结果2016-2018年昆明市手足口病病原监测结果显示,昆明市实验室诊断手足口病共2318例,其中,检出EV-A71阳性417例,CV-A16阳性883例,其他EV阳性1018例。2016年的优势病原为CV-A16(50.26%),2017和2018年优势病原均为其他EV,分别占56.06%和54.03%。从其他EV共分离出CV-A6毒株57株,均属于国内流行的D3a亚型。结论2016-2018年引起昆明市儿童手足口病的主要病原体是CV-A16和其他EV,应加强常规监测中其他EV的监测,并关注CV-A6毒株的持续流行。

Objective To understand the pathogenic spectrum of hand,foot and mouth disease(HFMD)and the genetic characteristics of coxsackievirus A6(CV-A6)strains in Kunming from 2016 to 2018.Methods The specimens of HFMD patients were collected from HFMD surveillance system of Yunnan from 2016 to 2018.Real-time RT-PCR was used for the detection of CV-A16,enterovirus A71(EV-A71)and other EVs.VP1 genes of other positive samples were amplified by routine RT-PCR and sequenced.The phylogenetic tree of CV-A6 was constructed by MEGA 5.2 software with the reference strains from Genbank and the molecular epidemiological characteristics were analyzed.Results Pathogenic surveillance results of Kunming from 2016 to 2018 showed that there were 2318 cases with HFMD,among whom 417 had EV-A71 infection,883 had CV-A16 infection,and 1018 had other EVs infection.In 2016,CV-A16 was the dominant pathogen(50.26%).In 2017 and 2018,the dominant pathogens were other EVs,accounting for 56.06%and 54.03%,respectively.A total of 57 CV-A6 strains isolated from other EVs belonged to sub-genotype D3a.Conclusions From 2016 to 2018,the main pathogens of HFMD in Kunming were CV-A16 and other EVs.The surveillance of other EVs in routine monitoring should be strengthened,and the continuing prevalence of CV-A6 needs to be paid more attention.