浙江省仙居县2012-2013年流行性乙型脑炎病毒基因特征和人群血清学研究  

Study on the genotypic characteristics of Japanese encephalitis virus and serology in the healthy population of Zhejiang province, 2012-2013

作　　者：严菊英[1] 潘金仁[1] 张意坚 周佳悦[1] 倪红年 张严峻[1] 

机构地区：[1]浙江省疾病预防控制中心,杭州310051 [2]仙居县疾病预防控制中心

出　　处：《中华流行病学杂志》2014年第10期1146-1150,共5页Chinese Journal of Epidemiology

基　　金：基金项目：国家“十二五”科技重大专项（2012ZX10004-210-002）

摘　　要：目的：分析浙江省仙居县媒介蚊虫中流行性乙型脑炎（乙脑）病毒（JEV）基因型别和健康人群乙脑抗体水平。方法2012-2013年在浙江省仙居乙脑监测点采集蚊虫，分离JEV，测定其E基因核苷酸序列，并进行同源性与进化分析；对监测点的642名健康人群，在乙脑流行季节前后，分别采集双份血清，共计样本1263份，检测JEV中和抗体。结果采集11650只蚊虫标本，分离25株JEV，同源性分析显示，2012-2013年分离到的JEV与浙江省1982-2010年JEV之间E基因核苷酸同源性为87.8%～99.7%，与乙脑疫苗株SA14-14-2之间核苷酸同源性为87.7%～88.0%。E基因进化分析显示，2012-2013年JEV属于基因Ⅰ型，E基因编码病毒毒力和抗原表位的位点未发生改变。健康人群JEV中和抗体阳性率为31.5%～42.0%，抗体几何平均滴度（GMT）为1∶2.56～1∶3.53，流行前后人群抗体阳性率（χ2≤1.76，P＞0.05）和GMT（u≤0.64，P＞0.5）差异均无统计学意义。结论2012-2013年浙江省仙居县蚊媒中携带基因Ⅰ型JEV，健康人群JEV中和抗体阳性率≤42.0%，流行前后抗体阳性率和中和GMT均无明显变化。Objective To understand the genotypic characteristics and the neutralizing antibody levels of Japanese encephalitis virus（JEV）and Japanese encephalitis（JE）in both vector mosquitoes and in healthy people of Zhejiang province. Methods Virus was isolated from mosquitos sampled from the Monitoring Stations located in Xianju county during 2012 to 2013. Phylogenetic and homological studies were carried out on the E gene. A total of 1 263 blood specimens from 642 healthy people were collected before and after the seasons of JE epidemics. JEV neutralizing antibody was detected by the micro-neutralization test. Results Twenty-five JEV strains were isolated from a total of 11 650 mosquitoes. The identity of nucleotide appeared as 87.8%-99.7% both from 2012 to 2013 and from 1982 to 2010 while as 87.7%-88.0%with vaccine strain SA14-14-2,in Zhejiang. The phylogeny tree of E gene indicated that the newly isolated virus belonged to genotypeⅠ but no mutation of amino acid sequence coding conformational epitope was identified in the envelop protein. Both positive rates and the geometric mean titer（GMT）of neutralizing antibody in healthy people were 31.5%-42.0%and 1∶2.56-1∶3.53 in Xianju county,during 2012 and 2013,respectively. Both of the two positive rates（χ2≤1.76,P〉0.05）and the two GMTs（u≤0.64,P〉0.5）for antibodies pre or post the epidemic season did not show significant differences. Conclusion JEV isolated in Xianju during 2012 and 2013 belonged to genotypeⅠ. The positive rates of JEV neutralizing antibody from healthy people in Xianju were less than 42.0%,which showed no significant differendes pre or post JE epidemic season.

关 键 词：流行性乙型脑炎病毒 基因型 中和抗体 健康人群 

分 类 号：R512.32[医药卫生—内科学]