关键词: 规模化猪场, HEV, 流行病学

Abstract: The infection and epidemical characterization of hepatitis E virus (HEV) in industrialized swine herds were investigated. Eighty serum samples collected from 4 pig farms were detected for anti-gG antibody by ELISA. Then from 2007 to 2009, clinical liver specimen and anal swabs were collected in Hubei province, Henan province, and Anhui province for HEV RNA detection by nest RT-PCR (RT-nPCR), PCR products were sequenced, and neighbour-joining method was utilized for phylogenetic analysis. 56 out of 80 serum samples were anti-HEV IgG positive. 5 out of 8 pig farms were HEV RNA positive and the positive rate was 62.50%. HEV RNA positive rate was 8.4% (35/415) in anal swabs, while HEV RNA positive rate was 15.55% (21/135) in liver. The minimal detection age of piglet is 7 days old and the maximum detection date is 84 days old. Two typical sequences were submitted to GenBank, the accession number is GQ202266.1 for a liver origin isolate and FJ445406 for an anal swab isolate. Phylogenetic analysis shows that the homology among 38 positive strains is 92%-100%, all the isolated strains belong to the genotype 4. The isolated HEV from the rectal swab strain (FJ445406) is at the same branch with swine-origin strain DQ279091, but the strain from the liver sample (GQ202266.1) exists on the same sub-brunch with a human strain. Taken together, our study shows that HEV circulates in pigs herds in central China, but generally speaking, HEV genotypes in this area remained stable and belong to the same genotype. Our data contributes the knowledge of HEV infection in industrialized pig farm and control of HEV spread between human and animal, especially pigs.

Key words: industrialized pig herds, Hepatitis E virus, epidemiology