盐城市2018—2019年手足口病和疱疹性咽峡炎病原学特征分析

The pathogenic features of hand, foot and mouth disease and herpangina in Yancheng City from 2018 to 2019

目的 探讨盐城市近年手足口病(hand foot and mouth disease, HFMD)和疱疹性咽峡炎病原学特征,以及柯萨奇病毒A组4型(Coxsackievirus A4,CVA4)、10型(CVA10)分离株VP1区序列分子进化规律。方法 收集全市哨点监测医院诊断为HFMD和疱疹性咽峡炎病例标本,采用实时荧光RT-PCR进行肠道病毒核酸检测,选取鉴定为CVA4和CVA10阳性标本开展VP1区序列测序,应用生物信息学软件构建系统进化树,分析核苷酸和氨基酸同源性和氨基酸变异位点。结果 2018—2019年,盐城市累计采集和检测1 289份病例标本,总体病毒核酸阳性检出率59.2%,HFMD和疱疹性咽峡炎阳性检出率分别为59.7%和57.1%,差异无统计学意义(χ^(2)=0.48,P=0.51);CVA6阳性检出率为31.3%,为优势血清型,EV71型、CVA16型、CVA6型、CVA10型、CVA4型样本阳性检出率差异均有统计学意义(P值均<0.05)。共分离12株CVA4型和31株CVA10型毒株,基因型均为F型和C型;分离毒株间核苷酸同源性分别为99.3%~100.0%和96.0%~100.0%,氨基酸同源性分别为91.3%~100.0%和99.3%~100.0%,亲缘关系较近;分别存在2个和4个氨基酸易变异位点。结论 盐城市2018—2019年HFMD和疱疹性咽峡炎病原体主要为CVA6型肠道病毒;CVA4和CVA10分离株流行基因型分别为F型和C型。

Objective To investigate pathogenic features of hand, foot and mouth disease(HFMD) and herpangina in Yancheng City from 2018 to 2019;to study the molecular epidemiological characteristics of VP1 region of coxsackievirus A4(CVA4) and 10(CVA10) isolated strains. Methods The samples of HFMD and herpangina patients were collected from the sentinel surveillance hospitals, real-time fluorescence PCR was used to test enterovirus nucleic acid, the CVA4 and CVA10 positive samples were selected to conduct VP1 region sequencing analysis.The phylogenetic tree was constructed, the homology of nucleotide and amino acid were analyzed, and amino acid variation siteswere calculated by bioinformatics software. Results A total of 1 289 HFMD and herpangina samples were collected and detected in Yancheng City from 2018 to 2019,the overall positive rate was 59.2%;the positive rates of HFMD and herpetic angina virus nucleic acid were 59.7% and 57.1%,respectively, with no statistical difference(χ^(2)=0.48,P=0.51).The positive detection rate of CVA6 was 31.3%,which was the dominant serotype.There was significant difference in the positive detection rates among EV71,CVA16,CVA6,CVA10 and CVA4 types(all P<0.05).A total of 12 strains of CVA4 and 31 strains of CVA10 were isolated, which belonged to genotype F and C.The nucleotide homology and amino acid homology of the isolates were 99.3%-100.0% and 96.0%-100.0%,respectively;indicating close relationship among all isolates.There were 2 and 4 heterotopic sites of amino acids identified, respectively. Conclusion The dominant pathogens of HFMD and herpangina in Yancheng City were enterovirus CVA6.The CVA4 and CVA10 isolates were F and C genotypes.