安庆市商品猪戊型肝炎病毒的分子流行病学调查

 目的 了解安徽省安庆市商品猪戊型肝炎病毒（hepatitis E virus，HEV）的流行病学特征。方法 2009年3月26日、6月20日、9月15日和12月8日分别在安庆市安庆屠宰场收集商品猪胆汁100份，共400份，并按采样时间将400份商品猪胆汁标本分为A、B、C、D4组。用巢氏RT PCR方法对HEV ORF2区域内150-nt序列进行扩增，测序后参照GenBank下载的参考序列作系统进化分析。结果 400份猪胆汁中有22份（5.5%）检测出HEV RNA，其中A~D各组的HEV携带率分别为9.00%、6.00%、3.00%、4.00%，各组间的HEV携带率差异无统计学意义（χ²=4.04，ν=3，P=0.26）。系统进化分析结果显示，检测到的猪HEV病毒株均属于基因4型，与1、2、3和4型参考病毒株的核苷酸同源性分别为80.40%~95.78%、82.10%~95.72%、77.31%~96.76%和89.51%~96.71%。基因4型样本病毒株内部又归为a或d两个亚型，且以a型为主。结论 安庆市商品猪的HEV携带率较高，基因4a型为该地区商品猪HEV的主要基因型，未煮熟的猪肉制品存在着食用安全隐患。

Molecular-epidemiological research on hepatitis E virus among commercial swine herds in Anqing,China

Objective To determine the epidemiological characteristics of hepatitis E virus (HEV) among commercial swine herds in Anqing, Anhui Province of China. Methods One hundred swine bile samples were collected from Anqing slaughterhouse on each day of Mar 26, Jun 20, Sep 15 and Dec 8 of 2009, respectively. The bile samples were divided into 4 groups, namely group A, B, C and D, according to the collection time. All the samples were tested for HEV RNA using the nested RT-PCR method. The ORF2 150-nt sequences of the HEV sample isolates were determined for phylogenetic analysis together with prototype sequences in the GenBank. Results Twenty-two of 400 bile samples (5.5%) were positive for HEV RNA. The HEV prevalences of group A, B, C and D were 9.00%, 6.00%, 3.00% and 4.00% respectively without significant differences among them (χ²=4.04, ν=3, P=0.26). Phylogenetic analysis revealed that all the swine sample HEV isolates were belonged to genotype 4, sharing 80.40%-95.78%, 82.10%-95.72%, 77.31%-96.76% and 89.51%-96.71% nucleotide sequence identities with prototype 1, 2, 3 and 4 HEV isolatesm, respectively. The sample isolates were further grouped into subtype a or d, and subtype a was the predominant genotype. Conclusions HEV is prevalent in commercial swine herds in Anqing, and genotype 4a HEV is the main causative agent. There is a potential risk of HEV cross-species transmission for humans to consume uncooked pork products.