2014年上海市手足口病的病原谱及EV-A71和CV—A16分子流行病学特征分析

Pathogen spectrum of HFMD and molecular epidemiology of EV-A71 and CV-A16 in Shanghai, 2014

目的研究2014年上海市手足口病的病原谱，及肠道病毒A组71型（EV-A71）和柯萨奇病毒A组16型（CV—A16）变异变迁规律。方法采集上海市2014年手足口病患者的咽拭子标本，进行核酸检测，对核酸检测结果为EV—A71、CV-A16以及其他EV阳性的临床标本进行病毒分离。对病毒分离结果阳性株进行全长VP1编码区基因的扩增以及核苷酸序列的测定和分析，然后与EV—A71、CV—A16各基因型和基因亚型的代表株构建亲缘性进化树。结果2014年上海市辖区共对2017例HFMD临床标本进行了核酸检测，共有1644例检测结果为阳性。从中随机地选择出75份临床标本接种RD细胞和Vero细胞，共有60份出现EV特征性CPE，病毒分离的阳性率为82．67％，其中23株被鉴定为EV—A71、32株被鉴定为CV—A16、5株被鉴定为其他EV。23株EV—A71全部属于C4a进化分支；32株CV—A16中，有8株属于BIa进化分支，有24株属于B1b进化分支。结论2014年上海市辖区手足口病呈现EV—A71与CV-A16共同流行的模式。C4a进化分支的EV—A71在上海市持续传播，而B1b进化分支成为上海市CV—A16的流行优势株。研究和掌握EV—A71和CV—A16等肠道病毒流行株的基因特征，发现其变异位点和变异趋势，对HFMD预防控制策略措施的制定将有重要的参考意义。

Objective To study the pathogen spectrum of HFMD and the rules of variable of EV- AT1 and CV-A16 in Shanghai Municipality in 2014. Methods Nasopharyngeal swabs were collected from HFMD patients in Shanghai Municipality in 2014, and viral RNA detection was performed. Viral isolation was performed on the specimens with the positive RNA detection for EV-AT1, CV-A16 and other EVs. Entire VP1 coding region amplification was performed and sequencing analysis was determined. Phylogenetic trees were constructed based on the entire VP1 sequences of all known genotypes and sub-genotypes of EV- A71 arid CV-A16. Results In 2014 in Shanghai Municipality, a total of 2017 clinical specimens collected from HFMD patients were tested, and 1644 were positive for EV-A71, CV-A16 and other EVs. 75 specimens were randomly selected to inoculate onto RD cell and Veto cell, and there were 60 specimens appeared special EV CPE with the positive rate of 82.67%. Among them, 23 strains were identified as EV- A71, 32 strains were identified as CV-A16, and 5 strains were identified as other EVs. 23 EV-A71 strains all belonged to C4a sub-genotype; and among 32 CV-A16 strains, 8 strains belonged to Bla sub-genotype, and other 24 strains belonged to Blb sub-genotype. Conclusions EV-A71 and CV-AI6 co-circulated in Shanghai Municipality in 2014. C4a sub-genotype of EV-A71 continued to spread in Shanghai, and Bib subgenotype of CV -A16 became predominant CV-A16 strains in Shanghai. For the HFMD prevention and control strategy, it is important to investigate the genetic characteristics of the epidemic, such as EV-A71, CV-A16 and other EVs.