上海地区猪戊型肝炎感染状况及病毒序列分析

目的] 调查上海地区猪戊型肝炎感染现况,掌握上海市猪感染戊型肝炎病毒的型别,以进一步探讨猪戊型肝炎感染与病人感染的可能关系。方法]采集上海市3个区的不同季度的3月龄猪血样,用ELISA法检测抗-HEV 特异性抗体水平,并用RT-nPCR方法检测猪粪便中HEV病毒,进行RNA核酸序列分析和基因进化树分析。 结果] 共检测猪血清标本1 798份,HEV抗体阳性率为89．38％;44份猪粪便样品中17份RT、-nPCR为阳性,HEV RNA阳性率为38．64％,病毒序列经同源性分析,与戊型肝炎病毒I、Ⅱ、Ⅲ、Ⅳ型的同源性分别为78．5％-84．0％、76．5％-80．7％、 77．3％-82．7％、84．6％-90．7％,基因进化树的分析显示,病毒序列与HEVⅣ型的ⅣA形成同一分支。结论] 上海地区的猪戊型肝炎感染率较高,戊型肝炎病毒型别属基因型Ⅳ型。

Investigation on HEV infection in swine and analysis with partial sequences of swine HEV virus in Shanghai

Objective] To investigate the HEV infection and its genotype of swine in Shanghai region and to explore the possible relationship between swine and human HEV infections. Methods] The serum samples of swine were collected from different herds of 3 districts in Shanghai and detected by ELISA. 44 Samples of feces were also collected and fecal extracts were detected by RT - nPCR to analyze the RNA sequences and draw out the phylogenetic tree. Results] 1798 swine serum samples were detected and the average positive rate of HEV infection in swine was 89. 38%. The HEV RNA positive rate was 38.64%. Sequences were aligned with human HEV sequences. Multiple sequence alignment showed that compared with human HEV genotype I,Ⅱ ,Ⅲ and Ⅳ, homologies at the nucleotide level were 78.5%-84.0%,76.5%-80.7%,77.3%-82.7% and 84.6%-90.7% respectively. The phylogenetic tree showed that the swine HEV genotype in part of Shanghai region belonged to IV and closely related to IVA.Conclusion] Swine HEV infection in Shanghai exists widely and the genotype is IV.