2011～2013年杭州市手足口病病原谱流行特征及柯萨奇病毒A16型VP1区基因变异研究

Epidemic characteristics of pathogen spectrum of hand-foot-mouth disease and genetic analysis of VP1 region of coxsackie virus A16 isolated from 2011 to 2013 in Hangzhou,China

目的了解杭州市手足口病病原谱流行特征及柯萨奇病毒A16型（CA16）分离株的VP1基因变迁规律。方法采集杭州市2011-2013年手足口病患者的2 197份临床标本,用通用引物进行肠道病毒实时荧光定量RT-PCR检测,对阳性标本进行分型,对部分CA16感染阳性重症患者标本测定VP1基因序列并进行同源性比对和系统进化树分析。结果杭州地区肠道病毒通用型核酸检出率为56.0%（1 317/2 197）,肠道病毒71（EV71）、CA16和其他肠道病毒的检出率分别为24.1%（530/2 197）、13.9%（306/2 197）和22.8%（501/2 197）。在咽拭子和粪便标本中EV71检出率均最高,分别为23.9%（301/1 258）和23.6%（148/627）,而在疱疹液标本中其他型肠道病毒检出率最高,为32.6%（76/233）,脑脊液标本中无CA16检出。咽拭子标本和粪便标本在发病初期的检出率较高,发病后第5天和第6天后检出率低于发病初期检出率,而脑脊液和疱疹液不同病程阶段的检出率无统计学意义。9株CA16分离株VP1基因的核苷酸同源性为90.8%-99.7%,分属于B1b亚型和B1a亚型。结论 2011-2013年杭州地区手足口病患者主要病原体以EV71和CA16为主,样本类型和采样时间是影响肠道病毒检出率的重要原因。杭州地区CA16毒株VP1区基因的变异程度较低,需进一步加强开展手足口病的监测。

Objective To understand the epidemic characteristics of pathogen spectrum in the patients with hand-foot-mouth disease（ HFMD） and variation pattern of VP1 gene of coxsackie virus A16（ CA16） isolates in Hangzhou district,China. Methods A total of2 197 specimens from the confirmed cases of HFMD from 2011 to 2013 were collected and identified by fluorescent quantitation RTPCR using universal primers of enterovirus. The positive samples were genotyped. For some severe patients with CA16 infection,VP1 genes were sequenced. The homology of VP1 was compared with Gen Bank and phylogenetic tree was analyzed. Results The positive rate of universal nucleic acid of enterovirus（ EV） was 56. 0%（ 1 317 /2 197） in Hangzhou. The positive rates of EV71,CA16 and the enterovirus of other subtype were 24. 1%（ 530 /2 197）,13. 9%（ 306 /2 197） and 22. 8%（ 501 /2 197）,respectively. EV71 held the highest detectable rates in pharyngeal swab and stool specimens,accounting for 23. 9%（ 301 /1 258） and 23. 6%（ 148 /627）,respectively,while the other subtypes of EV was the highest（ 32. 6%,76 /233） in herpes fluid specimens. No CA16 was detectable in cerebrospinal fluid specimens. The detection rates of CA16 in pharyngeal swab and stool specimens were high in the onset period of disease in but decreased significantly on the days 5 and 6 respectively. The detectable rates of cerebrospinal fluid and herpes liquid in the different stages showed no statistical difference. The nucleotide homology of 9 isolates of CA16 was between 90. 8% and 99. 7%,belonging to B1 b and B1 a subtypes. Conclusions The main pathogens of hand-foot-mouth disease in Hangzhou district were EV71 and CA16 from 2011 to 2013. The type of samples and the time of sample collection were the important influential factors for the detection rate. Low mutation degree in VP1 region of gene was shown in the CA16 strain prevailed in Hangzhou,and monitoring of hand-footmouth disease should be emphasized.