Diversity of hepatitis C virus genotypes among intravenous heroin users in Taiwan

Limited information is available about genotypes of hepatitis C virus (HCV) in intravenous heroin users in Taiwan. The purpose of this study was to examine the concordance of the detection of antibody to HCV and HCV-RNA and to determine the distribution of HCV genotypes in male intravenous heroin users.

This was a cross-sectional study. The study population included 274 intravenous heroin drug users newly sentenced in a male prison in central Taiwan from November 2004 to February 2005, whose antibodies to HCV were positive, and antibodies to human immunodeficiency virus were negative. The mean age was 33.9 years (standard deviation, 7.8). The molecular diagnosis used to identify HCV-RNA was PCR.

Among 274 subjects, 214 subjects were found to contain HCV-RNA. Positive predictive value of HCV infection using antibody to HCV as an indicator was 78.1%. Among 214 subjects, HCV genotype 2a was the most predominant (58.9%, n = 126), followed by 1a (17.3%, n = 37), 1b (14.5%, n = 31), 2b (8.9%, n = 19) and 1a + 2b (0.4%, n = 1). Age-specific analysis also showed genotype 2a was the most prominent genotype among the 4 age groups, with the highest prevalence in groups aged 20 to 29 years and 30 to 39 years (53.3% and 67.6%, respectively).

The concordance of antibody to HCV and HCV-RNA is remarkable in selected high-risk groups. HCV genotype 2a is the most prevalent in male intravenous heroin users in central Taiwan, especially in aged 20 to 29 years and aged 30 to 39 years.