广西14市猪戊型肝炎的分子流行病学分析

Molecular Epidemiology Analysis of Swine Hepatitis E in 14 Cities of Guangxi

为调查广西猪戊型肝炎(HE)的感染情况,本研究应用套式RT-PCR方法对采自广西14市43个猪场的508份3月龄左右猪只粪样及市售182份猪肝扩增猪戊型肝炎病毒(HEV)ORF2基因特异序列,并进行核苷酸序列同源性分析及遗传进化分析。结果表明,在508份猪粪样中194份可以检测到HEV RNA,阳性率为38.2%;182份猪肝样本中,33份可检测到HEV RNA,阳性率为18.1%;43个猪场中检出HEV RNA的有35个,猪场阳性率为81.4%。所获取的39株广西猪HEV ORF2基因特异序列同源性为89.9%～100%,提示在所调查的广西猪场中已较普遍存在HEV感染,所获取的39株广西HEV阳性样品均属于基因Ⅳ型。本研究结果佐证了感染猪及市售带毒猪肝脏是HEV重要的储存库和传染源,应该重视其公共卫生学意义,预防粪-口途径或者食源性HEV感染。

In order to investigate the molecular epidemiology of swine hepatitis E（HE） in Guangxi province,in this study,we collected a total of 508 feces samples of 3-month age from 43 different piggeries in 14 cities and 182 liver specimens purchased from markets.By using the nested reverse-transcription polymerase chain reaction（RT-PCR） method,we obtained the specific nucleotide sequence of ORF2 of hepatitis E virus（HEV） RNA and then we carried out the homology in nucleotide sequence and its analysis of genetic evolution.The results showed that HEV RNA in 194 of 508 samples could be found,which positive rate was 38.2%,besides,HEV RNA in 33 of 182 liver specimens could be detected,which displayed the positive rate of 18.1%,moreover,35 of 43 piggeries could be examined sharing HEV RNA with its positive ratio of 81.4%.The phylogeny analysis of ORF2 nucleotide sequence from 39 HEV RNA positive samples demonstrated that they shared homology with 89.9% ～100%,which revealed that the investigated piggeries had been infected HEV and all the positive strains belonged to genotype Ⅳ.The data of this research indicated that infected pigs and commercial pig livers with HEV sold in markets were the important reservoir and infection source of HEV,therefore,we should raise a public-health concern for defending fecal-oral or food-borne HEV infection.