Identification of genetic diversity of hepatitis E virus (HEV) and determination of the seroprevalence of HEV in eastern China.

Hepatitis E, caused by the hepatitis E virus (HEV), is endemic in China. However, the molecular characteristics of HEV circulating in eastern China and the seroprevalence of HEV infection in eastern China are relatively unknown. In this study, 25 HEV strains, isolated from sporadic hepatitis E cases in eastern China, were sequenced in the RNA-dependent RNA polymerase region and subjected to phylogenetic analysis. These HEV strains were 74.6-98.7% identical in nucleotides and were all clustered into HEV genotype 4. Most of them formed new sub-genotypes and revealed a high degree of genetic variance. In addition, 12,052 serum samples were collected from people of different ages, living in urban or rural areas in eastern China. Anti-HEV IgG activity was detected in 2073 (17.20%). The prevalence of anti-HEV IgG significantly increased with age (P<0.0001), ranging from 7.92% in children (<10 years old) to 21.48% among older persons (>or=60 years old). Moreover, statistical analysis showed that there was a significant difference between rural and urban areas, with higher prevalence for people living in rural neighborhoods (P<0.001).