Seroepidemiology And Genotype Analysis Of Hepatitis E Virus In The Northeast Of China

The aim of this study was to analyze the prevalence of infection and genotype of hepatitis E virus(HEV) in people and animals in the Northeast of China(Heilongjiang,Jilin and Liaoning provinces).This seroepidemiological study was conducted using enzyme immunoassays,human serum samples including 10 samples positive for HEV antigen and 116 samples positive for anti-HEV IgM,and animal serum samples including 132 samples positive for HEV antigen and 953 samples with an S/CO≤10 for anti-HEV were tested for HEV RNA using real-time fluorescent RT-PCR and nested RT-PCR.All positive amplicons from the nested RT-PCR were cloned and sequenced.The overall prevalence of anti-HEV antibody was 81.6%in pigs above 3 months of age,66.4%in pigs below 3 months of age, 18.7%in cattle and 12.4%in sheep.In humans,the overall prevalence of anti-HEV IgG was 31.6%(311/985),28.6%(147/514) and 21.1%(841/3994) in individuals:frequent,infrequent, and very rare contact with swine,respectively.71 samples were positive for HEV RNA using real-time fluorescent RT-PCR and 30 of the 71 samples were positive for HEV RNA using nested RT-PCR.These 30 isolates shared 81.2-100%sequence identity with each other at the nucleotide level and belonged to HEV genotypeⅣ.The results indicate that HEV infection is widely spread in the northeast of China.The prevalence of anti-HEV IgG in individuals with close contact with pigs was significantly higher than those without and the HEV sequences isolated from such individuals were related more closely to isolates from pigs. These support strongly the hypothesis of a zoonotic origin of hepatitis E.