Subtypes of genotype 3 hepatitis E virus in pigs.

The prevalence of hepatitis E virus (HEV) RNA in faecal and bile samples from pigs in abattoirs in Eastern and South Western China from 2006 to 2011 was determined by reverse transcriptase PCR. HEV-3 was detected in 4/5952 (0.07%) pigs and HEV-4 was detected in 287/5952 (4.8%) pigs. Two HEV-3 subtype 3a strains from South Western China had 87.1-89.7% sequence identity. Two HEV-3 subtype 3b strains from Eastern China had 91.8-93.8% sequence identity and were similar to strains reported previously in Eastern and Central China. The distinct subtypes of HEV-3 in different regions of China suggested multiple origins of HEV infection.