2010年-2011年湖南省郴州市手足口病病原谱和HEV71基因特性研究

Study on hand,foot and mouth disease pathogen spectrum and genetic characteristics of human eterovirus 71 in Chenzhou of Hunan province from 2010 to 2011

目的了解2010年～2011年郴州市手足口病的病原谱和人肠道病毒71型(HEV71)的基因特征。方法Real-time RT-PCR法检测人肠道病毒核酸;Rd细胞分离HEV71并作VP1区测序分析。结果 2010年的优势毒株为HEV71,呈春末夏初流行高峰;2011年无明显优势毒株,呈夏、冬季两个流行高峰。病例类型与病原体型别的构成比差异有统计学意义(χ2=51.3,P<0.001)。郴州分离株与安徽阜阳株的同源性最高;VP1蛋白质三级结构同源建模预测未发现有意义的突变位点,重症病例与普通病例无明显差异。结论郴州市手足口病疫情具季节性特征,病原体构成各异,HEV71的流行对郴州市手足口病疫情影响较大。分离的HEV71均为C4a基因亚型,其VP1区段未发现与神经毒性相关的突变位点。

Objective To study the etiology spectrum of hand, foot and mouth disease （HFMD） and genetic char- acteristics of Human eterovirus 71 in Chenzhou city, Hunan province from 2010 to 2011. Methods The clinical specimens of HFMD cases were examined by real time RT - PCR. HEV71 RNA positive specimens were conducted viral isolation and sequencing of HEV71 VP1 regions. Results Epidemiological surveillance data showed that the annual seasonality of HFMD epidemic was clear. The peak of epidemic of HFMD in 2010 was in late spring and ear- ly summer, from April to July; while that was in summer and winter in 2011. Significant differences were found in the constituent ratios of causative agents and patients manifestations （X2 = 51.3, P 〈0.01）. The Chenzhou strains showed highest nucleotide and amino acid homology with C4a genotype. No meaningful functional mutation of VP1 was observed by the protein structure homology - modeling server （ SWISS - MODEL）. Few nucleotide or amino acid sequence difference were found between HEVT1 strains from severe （dead） patients and mild patients. Con- elusion The HFMD epidemic in Chenzhou from 2010 to 2011 shows seasonal characteristics and the constituent ra- tios of pathogen varied in different seasons. HEV71 was the predominant pathogen of HFMD in Chenzhou city, which belonged to C4a genotype. No gene mutation of VP1 was found to associate with neurotoxicity.