Hepatitis C virus coinfection in a cohort of HIV-infected individuals from Santos, Brazil: seroprevalence and associated factors.

Although HIV/hepatitis C virus (HCV) coinfection has been recognized worldwide in individuals exposed to blood-borne and sexually transmitted diseases (STD), limited data are available on the epidemiology of this coinfection in Brazil. A cross-sectional study was carried out to estimate the prevalence of HCV seropositivity in a cohort of people living with HIV/AIDS in Santos, Brazil, and to investigate potential risk factors for HCV infection. Anti-HCV antibodies were sought by using two immunoenzymatic assays. Overall HCV seroprevalence was 36.2% (95% confidence interval [CI] 31.9-40.4%). However, it was significantly higher (84.8%, 95% CI 78.2-91.3%) among intravenous drug users (IDU) as compared to non-IDU (20.9%, 95% CI 16.8-25.1%) (p < 0.001). Multiple logistic regression analysis revealed that HCV seropositivity among IDU was independently associated with needle sharing (adjusted odds ratio [adjOR] = 4.28, p = 0.07) and with serologic evidence of exposure to other bloodborne agents: HBV (adjOR = 4.39, p = 0.01) and HTLV-I/II (adjOR = 6.43, p = 0.02). In contrast, no association with lifetime number of sexual partners, history of STD, or of sex with commercial sex workers (CSW) could be demonstrated. Among non-IDU, HCV seropositivity was independently associated with sexual partnership with IDU (adjOR = 2.15, p = 0.08) and with HBV seropositivity (adjOR = 1.71, p = 0.05), but not with engaging in oral or anal receptive intercourse or having sex with CSW. Results indicate that exposure to blood and sexual partnership with IDU constitute the main risk factors for HCV acquisition among HIV-positive patients in Santos, Brazil. Prevention of HCV spread in this population should thus include harm reduction measures and information on safer sex practices for both IDU and their sexual partners.