河北省手足口病病例的病原构成及EV71病毒基因特征分析

目的了解河北省不同地区、不同严重程度手足口病病例的病原构成情况及EV71病毒的基因特征。方法采集河北省不同地区的HFMD患者粪便、疱疹液、咽拭子标本进行核酸检测和病毒分离，同时结合所收集的HFMD患病例的居住地、疾病严重程度信息加以分析。选取18株EV71阳性分离株进行VP1编码区基因扩增和核苷酸序列测定和分析，与其它38株各基因型和基因亚型的EV71代表株构建系统发生树。结果2009年河北省HFMD临床诊断病例的EV阳性率为65．13％，其中以EV71为主，占阳性病例的58．0％（752／1296）。秦皇岛、邯郸、保定、邢台地区手足口病例以EV71感染为主，而衡水、沧州等地区则以CA16为主。轻型病例中EV71阳性率为37．74％，重症病例中EV71阳性率为80．64％，死亡病例检测13例，均为EV71阳性。18株EV71分离株的VP114核苷酸同源性为94．9％～99．8％，与C4亚型代表株的VP1区核苷酸同源性最高，为91．9％～99．6％。进化树结果显示，河北省EV71分离株与c4亚型代表株处于同一分支，并在C4a进化分支的不同簇中。结论2009年引起河北省手足口病流行的病原体主要为EV71和CA16。秦皇岛、邯郸、保定、邢台地区手足口病例以EV7I感染为主，而衡水、廊坊、沧州等地区则以CA16为主。EV71是重症病例的主要致病病原体。河北省EV71分离株为c4亚型C4a进化分支。

The pathogenic constitution of HFMD cases and the genetic characteristics of enterovirus 71 in Hebei

Objective To understand the pathogen composition and the EV71 genetic characteris- tics of different hand-foot-mouth disease （HFMD） patients in different areas of Hebei Province . Methods Virus isolation and nucleic acid detection were carried out on stool specimens, anal swab specimens, throat swab specimens, vesicle fluid specimens collected from the patients with HFMD disease. The VP1 genes of a total of Enterovirus 71 （EV71） strains were amplified by RT-PCR with specific primer pairs, then the PCR amplification products were sequenced to perform nucleotide sequence homology analysis and construct the phylogenetic tree with 38 genotype and subgenotype representative strains for analyzing the gene subtype andvariation in Hebei province. Results Enterovirus positive rate was 65.13% of clinical diagnosis of HFMD cases in Hebei Province in 2009. EV71 is the primary pathogen of HFMD, which accounted for 58.0% of EV positive cases. Qinhuangdao, Handan, Baoding and Xingtai had a high proportion of EV71, while Heng- shui and Cangzhou were major in CA16. The EV71 positive rate of normal cases was 37.74% , and the rate of severe cases was 80. 64%. And EV71 was detected in all the 13 dead cases. The homogeneity of VP1 nu- cleotide sequence of the 18 separated EV71 strains from Hebei Province was 94.4% ~99. 8%. While com- pared with C4 subgenotypes, the homogeneity was 91.9% -99. 6%. Conclusion EV71 and CA16 are the primary pathogen of HFMD of Hebei Province in 2009. Qinhuangdao, Handan, Baoding and Xingtai had a high proportion of EV71 , while Hengshui, Langfang and Cangzhou were major in CAI6. The EV71 strains belong to Cda evolution branch of C4 subgenotype by analyzing the EV71 and CA16 genetic characteristics and phylogenetic tree.