2014年陕西省柯萨奇病毒A10型相关手足口病的流行特征和其VP1区基因特征研究

了解陕西省手足口病(Hand,foot and mouth disease,HFMD)的致病病原体柯萨奇病毒A10型(CV-A10)的流行特征及VP1区基因特征。对2014年收集的HFMD病例标本,通过荧光定量PCR检测确定肠道病毒型别,对CV-A10引起的HFMD流行特征进行描述性分析。使用RD细胞进行病毒分离,RT-PCR扩增CV-A10的VP1区基因片段并进行序列测定,使用Meg Align软件进行核苷酸及氨基酸的同源性分析,并使用MEGA5.0软件构建系统进化树。2014年CV-A10是陕西HFMD病原谱中的第三大病原,占其他肠道病毒的57.71%,13例重症HFMD病例的致病病原体鉴定为CV-A10,占重症病例的9.03%。CV-A10感染HFMD病例以≤3岁年龄组儿童为主(83.07%),男女性别比为1.15∶1。发病时间主要集中在4～7月。实验室分离出101株CV-A10,覆盖全省10市(区)。完成测序的18株CV-A10核苷酸和氨基酸同源性分别为94.0%～100.0%和97.3%～100.0%,与A型原型株的核苷酸和氨基酸同源性分别为76.2%～77.5%和91.9%～93.0%,与近年来河北、湖南和河南地区流行株具有较高的同源性。系统进化显示陕西CV-A10分离株属于C基因型。CV-A10是2014年陕西HFMD的优势病原,能引起重症HFMD,本次分离到的CV-A10毒株均属于C基因型。

Epidemiological Characteristics and Genetic Characteristics of the VP1 Region of Coxsackievirus A10 Isolated from Patients with Hand,Foot and Mouth Disease in Shaanxi Province,China,in 2014

To study the epidemiological characteristics and genetic characteristics of the VP1 region of coxsackievirus A10(CV-A10) isolated from hand, foot and mouth disease(HFMD) cases in Shaanxi Province, China,in 2014. Clinical samples were collected from HFMD cases in 2014 and the enterovirus types were identified using real-time polymerase chain reaction(PCR). CV-A10 was isolated using RD cells, and VP1 of isolated strains was amplified by RT-PCR. MegAlignTM was used to analyze the homology of nucleotides and amino acids,and phylogenetic trees were constructed with MEGA5.0. The epidemiological characteristics of HFMD caused by CV-A10 were analyzed. CV-A10 was the third most common pathogen of HFMD in 2014. The positive rate of CV-A10 was 57.71% in the other enteroviruses. Thirteen cases of severe HFMD were caused by CV-A10,accounting for 9.03% of confirmed severe cases. The highest incidence rate of CV-A10 was for people under the age of 3 years, and the male-to-female ratio was 1.15: 1. Most cases with HFMD were found during April to July. Also, 101 strains of CV-A10 were isolated, and 18 strains were sequenced. The homology of nucleotides and amino acids among 18 strains was 94.0%~100.0% and 97.3%~100.0%, respectively. Compared with genotype-A strains, the homology of nucleotides and amino acids was 76.2%~77.5% and 91.9%~93.0%, respectively, and there was high homology with the epidemic strains in Hebei, Hunan and Henan Provinces in China in recent years. Phylogenetic trees showed that the highest homology was with genotype C. CVA10 was the major pathogen of HFMD in Shaanxi Province in 2014 and could cause severe cases. All strains isolated from HFMD cases in Shaanxi Province in 2014 belonged to genotype C.