Genetic variation of hepatitis C virus in a cohort of injection heroin users in Wuhan, China

Abstract

Since the majority of heroin abusers use injection as the primary route of admission, heroin abuse contributes significantly to the transmission of hepatitis C virus (HCV). We determined HCV infection and its genotype distribution among injection heroin users in Wuhan, the largest city in the central China. Eight hundred seventy-eight (84%) out of 1046 serum specimens from the injection drug users were positive for HCV antibody. Out of randomly selected 122 specimens positive for HCV antibody, seventy-eight (64%) had detectable HCV RNA with genotype 6a as the predominant strain (50%), followed by 3b (32.2%), 1a (8.1%), 1b (6.5%), and 3a (3.2%). HCV RNA levels in male heroin users were significantly higher (P=0.013) than those in the female subjects. Although there was no significant difference in HCV RNA levels among the specimens positive for HCV 6a and 1a/1b, the samples with 6a or 1a/1b contained higher levels of HCV RNA than the specimens positive for HCV 3b (P=0.019, P=0.012, respectively). These findings indicate that there is a high prevalence of HCV infection with genotypes 6a and 3b as predominated strains among injection heroin users in Wuhan, China.

Figure 1

Phylogenetic tree of HCV strains from 70 injecting heroin users at two detoxification centers in Wuhan. The analysis was performed on 474nt within C-E1 region of HCV by using the neighbor-joining method in the PHYLIP package. Bootstrap analysis values (percentages) are shown in italics. The bar at the base of the figure shows the scale for nucleotide substitution per site. Analyzed samples indicated with two digits at the head of a capital letter e.g., 35C, or five digits represented the IDs of samples e.g. 51153; Accession numbers were used for the IDs of the genotype-known reference strains with two digits indicating genotypes at the head of the number (e.g. 3k.D88471) and were labeled by •.