高中生乙型肝炎血清学及S基因序列进化分析

Prevalence of hepatitis B virus infection and phylogenetic analysis of HBV S gene among high school students

目的了解江苏省海门市高中生乙型肝炎感染情况及其HBV S基因的变异情况。方法采用整群抽样方法抽取江苏省海门市职业中心校的407名高三学生进行乙肝血清学调查;采用酶联免疫吸附法(ELISA)和巢氏聚合酶链式反应(PCR)扩增方法检测血清样本的乙型肝炎表面抗原(HBsAg)、乙型肝炎病毒表面抗体(抗-HBs)和乙型肝炎病毒(HBV)S基因并进行进化分析。结果 407名高中生中乙肝表面抗原(HBsAg)阳性率为6.39%;在家中、乡镇卫生院和县级及以上医院出生学生的HBsAg阳性率分别为11.76%、8.02%和2.27%,差异有统计学意义(P<0.05);抗-HBs滴度≥10U/L者占72.5%,且呈U形分布;不同乡镇、不同性别学生抗-HBs滴度差异有统计学意义(P<0.01);407名高中生HBV S基因均为C基因型,主要变异在蛋白疏水区,抗原决定簇a区未发生免疫原性改变。结论出生时接受的医疗水平对HBV感染有影响;海门市高中生HBV S基因受到正选择作用而出现变异,但未发生免疫原性改变。

Objective To understand the hepatitis B infection and HBV S gene variation among high school students in Haimen city,Jiangsu province.Methods A serological survey of hepatitis B was conducted in a high school with cluster sampling method.HBsAg and anti-HBs were detected with ELISA,and phylogenetic analysis for HBV S gene with nested PCR.Results HBsAg positive rate was 6.39% and the rate for the students born at home,township health centers,and hospital above the county level was 11.76%,8.02%,and 2.27%,respectively,with significant difference（P0.05）.The percentage of the students with anti-HBs titer ≥ 10U/l was 72.5%,and the titer distribution was U-shaped.The difference in anti-HBs titer between boys and girls,as well as different towns,was statistically significant（P0.01）.All genotype of HBV S gene was C-type,and the main variation was in protein hydrophobic area.The change of immunogenicity in antigenic determinant ＂a＂ zone was not observed.Conclusion The level of health care at birth can affect the HBV infection among high school students in Haimen.S gene variation occurs through positive selection,but not antigenicity.