2014-2016年昆明市手足口病非EV-A71、非CV-A16肠道病毒流行情况及基因特征

目的 探讨 2014-2016年昆明市引起手足口病的非 EV-A71、非CV-A16肠道病毒的病原构成及优势型别基因特征，从而为本地区手足口病防治提供科学依据。方法 收集 2014-2016 年昆明市手足口病病例标本3767份，应用Real-time PCR法检测非EV-A71、非CV-A16肠道病毒并用RT-PCR方法扩增其阳性分离株的VP1基因片段，对扩增产物进行测序。利用序列结果进行型别鉴定，分别与各型代表株进行核苷酸、氨基酸同源性比较，构建系统进化树。结果 2014-2016年共检测标本3676份，检出908份非EV-A71、非 CV-A16肠道病毒核酸阳性病例标本，其中CV-A6型545例，CV-A10型158例，未分型205例。与引起手足口病的肠道病毒流行特征一致，非EV-A71、非 CV-A16肠道病毒高发季节为4-7月；发病人群以6岁及以下儿童为主，尤以1～3岁儿童发病率最高；男、女病例比例为1.65[DK]∶1，男性明显高于女性。进化分析显示，昆明市CV-A6 型和CV-A10型肠道病毒的 VP1序列与其各自的原型株同源性相对较低，与国内分离株有较高同源性。 结论 2014-2016年昆明市的非EV-A71、非CoxA16型肠道病毒型别多样，优势型别主要是CV-A6型，处于F4亚分支；其次是CV-A10型，为C基因型。

Epidemiological and etiological characteristics of hand-foot-mouth disease caused by non-EV-A71 and non-CV-A16 enteroviruses,Kunming, 2014-2016

Objective To explore the pathogenic spectrum and predominant type of non-EV-A71, non-CV-A16 enteroviruses which caused hand-foot-mouth disease (HFMD) in Kunming City during 2014-2016, and to provide evidence for the prevention and control of HFMD. Methods A total of 3,767 specimens of HFMD were collected from 2014 to 2016, and non-EV-A71 and non-CV-A16 enteroviruses were detected by real-time PCR. RT-PCR and sequencing were done for VP1 gene of isolated strains and the genotyping of non-EV-A71 and non-CV-A16 enteroviruses was performed. Phylogenetic tree was constructed with the reference strains, and its nucleotide and amino acid identities were calculated. Results A total of 3,676 specimens of HFMD were detected and 908 specimens were identified as non-EV-A71 and non-CV-A16 enteroviruses positive from 2014 to 2016, including 545 cases of CV-A6, 158 cases of CV-A10 and 205 cases of Unidentified. The epidemiological characteristics of non-EV-A71 and non-CV-A16 enteroviruses were consistent with the EV-U. The high-occurrence months were from April to July. The majority of cases were children under 6 years old, especially among 1 to 3 year-old-group. Male cases were more than female cases (1.65[DK]∶1). Phylogenetic analysis showed that the VP1 sequences of the CV-A6 and CV-A10 enteroviruses in Kunming had relatively low homology with their prototype viruses described in the NCBI database, while high homology with those isolated in China. Conclusion Hand-foot-mouth disease in Kunming from 2014 to 2016 is concerned with diverse non-EV-A71 and non-CV-A16 enteroviruses. CV-A6 is the predominant type which located in subgenogroup F4 among non-EV-A71, non-CV-A16 enteroviruses. Next came CV-A10, which is belonged to genogroup C.