The serological prevalence and genetic diversity of hepatitis E virus in farmed rabbits in China

Abstract

We identified and characterized a novel virus, designated rabbit hepatitis E virus (HEV), in rex rabbits farmed in China. Rabbit HEV is genetically related to but distinct from other known mammalian HEVs and avian HEV and may represent a novel genotype. To evaluate the spread and genetic variation of rabbit HEV, a total of 1094 serum samples were collected from various breeds of rabbits across ten counties in China. All sera were screened for the presence of anti-HEV antibody, HEV antigen and viral RNA. A total of 169 samples (15.4%), from nine of the ten counties, were found to be positive for HEV antibody. The seroprevalence was highest in Wuhan, Hunan Province (53.4%, 55/103). Samples positive for HEV antigen were detected in seven counties and the overall prevalence was 3.7% (41/1094). HEV RNA was detected in 22 samples and all but one of these samples was found to be positive for HEV antigen. Sequence analysis of the 304bp amplicons within open reading frame 2 showed that all HEV isolates in this study clustered with known rabbit HEV strains, in a branch separate from genotypes 1 to 4. The rabbit HEV strains were genetically heterogeneous and divided into divergent groups. Strains from the same geographic region tended to cluster together. These results indicate that rabbit HEVs with considerable genetic diversity are prevalent in farmed rabbits in China. The potential zoonotic risk of rabbit HEV needs to be investigated and evaluated further.