武汉地区散发性急性戊型肝炎流行特点和病毒基因型分析

Epidemiological characteristics and genotype of HEV isolated from patients with acute hepatitis E in Wuhan area

目的:探讨武汉地区散发性急性戊型肝炎流行特点和病毒基因型。方法:采用逆转录-巢式聚合酶链反应(RT-nPCR)检测162份急性戊型肝炎患者血清HEV RNA,并对PCR产物进行测序及同源进化分析。结果:武汉地区急性戊型肝炎患者男女比例为4.40∶1,30～59岁年龄段占71.60%,162份急性戊型肝炎患者血清有41份HEVRNA阳性,阳性率为25.31%,同源进化分析表明41株HEV毒株均属于基因Ⅳ型,各毒株间的核苷酸同源性为84.7%～100%,基因Ⅳ型又可进一步分为5种亚型,即Ⅳ-A、Ⅳ-B、Ⅳ-C、Ⅳ-D和Ⅳ-E,各亚型内部的核苷酸同源性分别为91.3%～100%、98.0%、92.0%～100%、98.0%～100%、100%,其中Ⅳ-A与上海株、西安株和广西株的核苷酸同源性分别为92.0%～97.3%、94.7%～99.3%和91.3%～96.0%,Ⅳ-D与北京株的核苷酸同源性为95.3%～96.7%。结论:武汉地区急性戊型肝炎以男性多见,好发于30～59岁年龄段,且均由基因Ⅳ型HEV引起,基因Ⅳ型又可进一步分为Ⅳ-A、Ⅳ-B、Ⅳ-C、Ⅳ-D和Ⅳ-E 5种亚型,其中Ⅳ-A与上海株、西安株和广西株亲缘关系较近,Ⅳ-D与北京株亲缘关系较近。

Objective：To investigate the epidemiological characteristics and genotype of hepatitis E virus（HEV） in Wuhan area.Methods：One hundred sixty-two serum samples collected from patients with acute hepatitis E were tested for HEV RNA by reverse transcription-nested polymerase chain reaction（RT-nPCR）.The PCR products were sequenced and used for phylogenetic analysis.Results：The ratio of male and female patients with acute hepatitis E was 4.40∶1.The patients aged from 30 to 59 years accounted for 71.60%.Forty-one out of 162 serum samples were positive for HEV RNA.The positive rate was 25.31%.Phylogenetic analysis showed that the 41 isolates belonged to HEV genotype Ⅳ.They shared 84.7.0%～100% identity with each other at the nucleotide level.The genotype Ⅳ isolates could be further divided into 5 subtypes,designating as A～E.The nucleotide sequence homologies within the five subtypes were 91.3%～100%,98.0%,92.0%～100%,98.0%～100% and 100%,respectively.Subtype Ⅳ-A had 92.0%～97.3%,94.7%～99.3% and 91.3%～96.0% nucleotide sequence homology with the HEV isolates from Shanghai,Xian and Guangxi.Subtype Ⅳ-D had 95.3%～96.7% nucleotide sequence homology with the HEV isolate from Beijing.Conclusion：AHE mostly occurs in male.People aged from 30 to 59 years are more susceptible to infection.The pathogen of acute hepatitis E is HEV genotype Ⅳ in Wuhan area.The genotype Ⅳ isolates could be further divided into 5 subtype,designating as Ⅳ-A to Ⅳ-E.There is a close relationship between subtype Ⅳ-A and Shanghai,Xian and Guangxi strains.There is a close relationship between subtype Ⅳ-D and Beijing strain.