2018年青海省手足口病病原谱的构成及基因特征分析

Analysis of the pathogenic spectrum of hand-foot-mouth disease in Qinghai Province in 2018

目的了解2018年青海省手足口病(HFMD)病原谱的构成及基因特征,掌握HFMD主要致病原的流行规律。方法采集青海省HFMD患者的咽拭子标本共713份,进行实时荧光定量检测和病毒分离;对阳性标本进行特异性引物核酸扩增和测序分析,参考NCBI部分毒株序列构建基因进化树。结果2018年共采集临床确诊HFMD患者标本713份,检测到EV-A71型病毒9份,CVA16型病毒109份,CVA6型病毒510份,CVA10型病毒12份,CVA4型病毒5份,CVA2型病毒2份,柯萨奇B组病毒4份,阴性3份。其中CVA6病毒占总数的71.53%,CVA16病毒占15.29%。经测序后选取典型的15株柯萨奇病毒A、B组基因序列进行核酸序列分析,同源性在23.5%-100%之间,表明引起青海HFMD流行的非EV-A71、CVA16型柯萨奇病毒A、B组核酸序列不同基因型之间的变异性强。结论2018年青海省HFMD病毒谱包括EV-A71、CVA16、CVA6等,主要为CVA6,其次是CVA16。

Objective To reveal the pathogen profile and genetic characteristics of hand,foot,and mouth disease(HFMD)in Qinghai Province in 2018 in order to understand the regularity of outbreaks of the main pathogens causing HFMD.Methods A total of 713 throat swab specimens were collected from patients with HFMD in Qinghai Province.Specimens were subjected to real-time PCR,viruses were isolated,and their DNA was sequenced.The nucleotide sequences were analyzed using DNAMAN and ClustalX.A phylogenetic tree was generated using the Neighbor-Joining(NJ)algorithm by comparing isolates with reference strains from the NCBI.Results In 2018,9 patients were positive for EV-A71(1.26%,9/713),109 were positive for CVA16(15.29%,109/713),510 were positive for CVA6(71.53%,510/713),12 were positive for CVA10(1.68%,12/713),5 were positive for CVA4(0.70%,5/713),2 were positive for CVA2(0.28%,2/713)and 4 were positive for Coxsackie Group B(0.56%,4/713).This indicated that CVA6 was the predominant isolate causing HFMD in Qinghai Province in 2018.Three patients were negative(0.42%,3/713).The sequences of 15 typical coxsackie A and B viruses were selected and analyzed.Sequence similarity ranged from 23.5%to100%,indicating that the nucleotide sequences of non-EV-A71 and CVA16 genogroups A and B varied substantially among different genotypes,and four clusters were generated in the phylogenetic tree.Conclusions In 2018,the viruses that caused HFMD included EV-A71,CVA16,CVA6,CVA10,CVA4,CVA2,and Coxsackie Group B in Qinghai Province.CVA6 was predominant,followed by CVA16.