HEV sero-epidemiology and genotypes among pigs in Lanzhou city

Objective To investigate hepatitis E virus (HEV) sero-epidemiology and genotypes among pigs in Lanzhou city.Methods The serum samples of pigs collected from Lanzhou city were detected for anti-HEV antibody and HEV antigen with ELISA diagnostic kits.The samples positive for HEV antigen were cloned and sequenced.The sequences were analyzed with software and their genotypes and subtypes were determined.Results The positive rates for anti-HEV antibody were 90.27% and 86.99% among pigs less than 3-month-old and more than 3-month-old,respectively.While the positive rates of HEV antigen were 1.56% and 2.35%.There was no significant difference in prevalence of anti-HEV antibody or HEV antigen between the two groups.Seven of 22 antigen positive sera were positive for HEV RNA and 82.2%-99.3% of them were identical with genotype 4 at the nucleotide level belonging to subtype 4a,4d and 4f,respectively.Conclusion HEV infection among pigs exists in Lanzhou city and the strains belong to genotype 4.