Diverse Genotypes of Hepatitis C Virus in Voluntary Blood Donors in Shanghai, China

Background: Prevalence of hepatitis C virus (HCV) in voluntary blood donors (VBD) in China has decreased progressively. However, it was still higher than those in developed countries and some developing countries. Methods: A total of 38952 VBD in Shanghai, China, were recruited in the study. The donated blood specimens were examined for anti-HCV antibody by ELISA. Hepatitis B virus DNA, HCV RNA, or HIV-1 RNA was subsequently tested by nucleic acid test (NAT) in the specimens negative for anti-HCV. A 377-nt partial sequence in HCV NS5B region was amplified in the specimens positive for anti-HCV or positive by NAT. To conduct a phylogenetic analysis, 179 sequences most phylogenetically identical to the VBD strains with BLAST search were retrieved in the GenBank and thirty nine 377-nt partial sequences isolated contemporaneously in local intravenous drug users (IDU) were included. Results: Overall prevalence of anti-HCV antibody in VBD was 0.46% (179/38952). Varying along demographics, the prevalence was higher in those aged 18-30 years and first donors. A total of thirty seven 377-nt partial sequences were amplified in the specimens positive for anti-HCV, whereas they were not seen in those negative for anti-HCV while positive by NAT. HCV genotype 1b was most predominant in VBD, followed by 2a, 3a, 1a, 3b, 6n, and 6a; in contrast, genotypes 3a and 3b were dominant in IDU. In genotypes 3a, 3b, 6a, and 6n, VBD and IDU strains shared high sequence identities and clustered together. In genotype 1b, VBD strains were phylogenetically identical to the sequences isolated across China, of which some were clustered more closely with IDU strains than the retrieved sequences. Conclusions: HCV prevalence in VBD in Shanghai remained low. However, there were diverse genotypes of HCV that were identified in VBD. HCV transmission from high-risk population to general population is likely to occur.