Esmaeili A, et al. – This study was undertaken to assess differences in hepatitis C virus (HCV) incidence by sex in people who inject drugs (PWID). Findings suggested an increased risk of HCV acquisition among women who inject drugs in comparison to men, independent of demographic characteristics and risk behaviors. It was observed that multiple factors, including biological (hormonal), social network, and differential access to prevention services, could contribute to increased HCV susceptibility in women who inject drugs.

Methods

• Researchers here used a large international multi–cohort set of pooled biological and behavioral data from prospective observational studies of incident HIV and HCV infections in high–risk cohorts (the InC3 Collaborative).
• They estimated HCV infection date based on a hierarchy of successive serological (anti–HCV), virological (HCV RNA) and clinical (symptoms and/or liver function tests) data.
• Cox proportional hazard model was utilized to calculate the crude and adjusted female to male (F:M) hazard ratio (HR) for HCV incidence using biological sex as the main exposure.

Results

• Researchers identified 1868 PWID over 3994 person–years observation (PYO).
• They realized unadjusted F:M HR of 1.38 (95%CI: 1.15, 1.65) and this remained marked after adjusting for behavioral and demographic risk factors 1.39 (95%CI: 1.12– 1.72).
• Despite association of syringe and equipment sharing with the highest HCV incidence rate in females (41.62 and 36.83 PYO, respectively), there appeared no sex differences attributed to these risk factors.