Epidemiology of hepatitis C virus infection & liver disease among injection drug users (IDUs) in Chennai, India

Background & objectives: We characterized HCV antibody prevalence, viral persistence, genotype and liver disease prevalence among IDUs in Chennai, India as the study of the association of HIV with each of these states is important and there are no data available. Methods: Between 2005-2006, 1158 IDUs were recruited and followed semi-annually. All were tested for HCV antibodies at baseline; a random sample of 400 antibody positives (200 HIV-positive and 200 HIV-negative) were tested for HCV RNA; 13 of these were sequenced. Assessment of asparate amino transferase (AST)-to-platelet ratio index (APRI) was done on 557 IDUs. Prevalence ratios of each outcome were examined. Results: Median age was 35 yr; 99 per cent were male. HCV antibody prevalence was 55 per cent and was associated with older age, being unmarried, longer injection history, tattoo and injecting at a dealer's place. Of the 400 HCV antibody positive IDUs, 281 (70.3%) had persistent infection which was less common among hepatitis B-infected persons but not associated with HIV. Of the 13 samples sequenced, 11 (85%) were HCV genotype 3a. Fibrosis prevalence according to APR! was: HIV/HCV-uninfected, 4 per cent; HIV mono-infected, 3 per cent; HCV mono-infected, 11 per cent; HIV/HCV co-infected, 12 per cent (P<0.001). In addition to being associated with HCV and HIV/HCV, fibrosis prevalence was higher among those drinking alcohol frequently; daily marijuana use was protective. Interpretation & conclusions: Our findings show that IDUs in Chennai have high HCV prevalence and associated disease burden. The burden will increase as access to antiretroviral therapy improves particularly given the high prevalence of HIV, HCV and alcohol use.