2007年内蒙古一起手足口病暴发的流行病学和病原学分析

The Epidemiologic and Virological Analysis of an Outbreak of Hand,Foot,and Mouth Disease in Inner Mongolia in 2007

2007年内蒙古自治区鄂尔多斯市准格尔旗暴发了一起手足口病疫情,患者大多出现发热症状,在手、足、口腔和臀部等一个或多个部位出现斑丘疹或疱疹。患者以5岁以下散居幼儿为主,暴发过程中有一个明显的发病高峰。从28名住院儿童采集了23份粪便标本和6份咽拭子标本进行病毒分离,共分离到了15株肠道病毒,其中9株鉴定为人肠道病毒71型(HEV71,分离率为31.03%),1株鉴定为柯萨奇病毒A组16型(CVA16)。结合分析这起暴发中患者的临床表现、流行病学调查结果以及实验室检测结果,表明HEV71可能是引起这起HFMD暴发的主要病原体。9株HEV71分离株在全长VP1区核苷酸水平和氨基酸水平上差异都较小,核苷酸和氨基酸同源性分别高于99.4%和99.0%,说明这起疫情是由同一个病毒传播链引起的。同源性进化分析结果表明,从这起疫情中分离到的HEV71属于C4基因亚型,而C4基因亚型自1998年首次在广东省深圳市报道以来,一直在我国持续流行,是中国大陆HEV71流行的优势基因亚型,提示C4基因亚型HEV71在中国大陆可能有较广泛的分布和传播。

In 2007, an outbreak of hand, foot, and mouth disease （HFMD） occurred in Jungar Banner, Erdos city, Inner Mongolia Autonomous Region, China Fever, vesicular exanthema on the hands, feet, mouth, and buttocks were presented in most of the patients. Most of the patients were infants less than 5 years old, and an obvious peak period appeared in the disease outbreak. From 28 hospitalized patients, 23 stool specimens and 6 throat swab specimens were collected for enterovirus isolation, and 15 enteroviruses were isolated, 9 were identified as Human Enterovirus 71 （HETV71,the isolation rate is 31. 03%） and 1 was identified as Coxsackievirus A16 （CVA16）. According to the comprehensive analysis of clinical manifestation, epidemiology data and laboratory results, this outbreak was probably mainly caused by HEV71. The variability at nucleotide acid level and amino acid level among 9 HEV71 was relatively low, and the homology was more than 99.4% and 99.0% respectively, showing that this outbreak was caused by only one viral transmission chain. Phylogenetic analysis of 9 HEV71 strains isolated during this outbreak re- vealed that they all belonged to subgenotype C4, which has been continuously circulating in China's Mainland since its first reported occurrence in Shenzhen City in 1998. It was also suggested that subgenotype C4 HEV71 had a widely distribution and transmission in China's Mainland.