Prevalence of a newly identified SEN virus in China

To establish nested-PCR methods for the detection of SENV-D and SENV-H and to investigate the epidemiology of SEN virus in China.

According to published gene sequences, primers from the conserved region were designed. Then, 135 samples from healthy voluntary blood donors and 242 samples from patients with various forms of liver disease were detected by nested-PCR of SENV-D/H. Some PCR products were cloned and sequenced.

By sequencing, the specificity of genotype-specific PCR was confirmed. SENV-D/H DNA was detected in 31% of the blood donors, which was higher than those in America and Italy (2%), and in Japan and Taiwan (15-20%). The prevalence of SENV-D/H viremia was significantly higher in patients with hepatitis B and hepatitis C than in blood donors (59-85% vs 31%, P<0.05). The prevalence among patients with non-A-E hepatitis was significantly higher than among blood donors (68% vs 31%, P<0.01), and equivalent to that among patients with hepatitis B and C.

Nested-PCR with genotype-specific primers could serve as a useful SENV screening assay. SENV has the same transmission modes as HBV and HCV. The high prevalence in patients with non-A-E hepatitis may attribute to the transmission modes, and SENV may not serve as the causative agents.