Genotype 4 Hepatitis E Virus Prevalent in Eastern China Shows Diverse Subtypes

BACKGROUND Hepatitis E Virus (HEV), a zoonotic pathogen, uses several species of animal as reservoirs. Swine is considered as the major reservoir for HEV infection in humans. Genotype 4 HEV is the dominant cause of hepatitis E disease in humans in China. OBJECTIVES Although many researches revealed that genotype 4 HEV is the main genotype that prevalent in eastern China, few researches have done to study the subtype of HEV in this area. Thus, this study aimed to investigate the subtype of HEV prevalent in eastern China. MATERIALS AND METHODS A total of 125 anti-HEV IgM positive human serum and 290 swine fecal samples were subjected to reverse transcription polymerase chain reaction (RT-PCR) screening of HEV RNA. Positive PCR products were sequenced and phylogenetically analyzed. RESULTS From a total of 125 human serum samples, 19.2% (24.125) were positive, while 9.66% (28.290) of the 290 swine fecal samples were positive for HEV RNA. Phylogenetic analysis based on partial capsid gene showed that the 51 HEV strains in the current study all belonged to genotype 4, clustering into 6 different subtypes. Our results also revealed that some of HEV isolates prevalent in the human and swine populations were classified into the same clusters. CONCLUSIONS Genotype 4 HEV in eastern China shows subtype diversity and some HEV isolates are involved in cross-species transmission.