福建省2011-2014年手足口病相关病原柯萨奇病毒A组10型的分子流行病学研究

Molecular epidemiology of hand-foot-mouth disease associated pathogen Coxsackievirus A10 identified in Fujian province, 2011-2014

目的 了解2011-2014年福建省手足口病相关病原其他肠道病毒中优势血清型柯萨奇病毒A组10型（Cox A10）的分子流行病学特征。方法 对2011-2014年福建省确诊为其他肠道病毒感染的1525例手足口病病例咽拭子和肛拭子标本进行病毒培养和鉴定分型,扩增、测序并分析其中优势血清型Cox A10的完整VP1区基因片段。结果 共分型鉴定出407例其他肠道病毒病例,包括Cox A10病例103例（占25.3%）。Cox A10病例在2011-2014年福建省手足口病病原谱的年度构成比分别为11.0%、6.0%、18.4%和9.2%。与手足口病总体疫情相比,Cox A10病例在地区、性别、年龄组的分布上没有特异性,致重症率较高。VP1区基因序列分析显示,Cox A10福建分离株与原型株的核苷酸序列同源性较低（76.0%-77.1%）,氨基酸序列同源性为91.9%-93.6%。进化分析显示,Cox A10福建分离株与原型株及国外地区分离株的亲缘关系远,与国内地区分离株的亲缘关系近。Cox A10福建分离株分布在进化树上的多个分支。结论 Cox A10为2011-2014年福建省手足口病的主要病原之一。Cox A10福建分离株与国内相应分离株同进化共循环。

Objective To study the molecular epidemiology of hand-foot-mounth disease（HFMD） associated Coxsackievirus A10（Cox A10） identified in Fujian province. Methods A total of 1525 specimens from non-EV71 non-Cox A16 HFMD patients were collected during 2011-2014. Isolated virus strains were identified and sub-typed. Full-length coding regions for the VP1 gene of the predominant serotype Cox A10 isolates were amplified and sequenced. Results Among the 407 non-EV71 non-Cox A16 HFMD cases confirmed by virus isolation and molecular subtyping, 103（25.3%） were caused by Cox A10, accounting for 11.0%, 6.0%, 18.4% and 9.2% among the HFMD-associated entero-viruses identified in 2011, 2012, 2013 and 2014, respectively, in Fujian province. Compared to the general features observed in the HFMD epidemics, no differences on the Cox A10-specificity rates were observed among factors as geographical origins, gender or age groups, but all with high rates of severity. Data from the nucleotide sequence analyses on VP1 genes showed low homology levels of 76.0%-77.1% among Cox A10 strains from Fujian province, in contrast to the prototype Cox A10 strain, but with high levels of homology in the amino acid sequences（91.9%-93.6%）. Results from the Phylogenetic analysis also indicated that Cox A10 isolates from Fujian province were distinct from the prototype strain or other isolates from other countries but was homologous to domestic strains, but the Fujian isolates clustered into multiple branches. Conclusions Cox A10 remained one of the predominant serotypes of HFMD in Fujian province. Cox A10 isolates identified in Fujian province were co-circulating and co-evolving with other domestic strains.