Identification of mechanisms of hepatitis C virus (HCV) acquisition among HIV-infected people is critical for prevention guidance. The aim of this study was to investigate risk factors for HCV infection and variations in HCV genotype distribution in a cohort of HIV-HCV coinfected patients in Brazil. This was a cross-sectional observational epidemiological study of a cohort of HIV-HCV coinfected individuals seen at a referral center for HIV-infected patients in the city of São Paulo between January and December 2017. The time of HCV acquisition, as determined by chart review, was categorized as before 2000, between 2000 and 2009, and from 2010 onward. HCV genotypes were determined by gene amplification and analysis. Among 3,143 HIV-infected individuals analyzed, 362 (11.5%) were HCV-HIV coinfected. Overall, the reported modes of HCV acquisition were sexual exposure in 172 (47.5%), injection drug use (IDU) in 86 (23.8%), use of inhaled drugs in 67 (18.5%) and blood transfusion in 10 (2.8%) individuals. All individuals who acquired HCV after IDU became infected before 2010. HCV acquisition by sexual contact was reported by 26.4%, 65.9%, and 63.8% of patients before 2000, between 2000 and 2009, and from 2010, respectively. There was an increase (p < .001) in the proportion of cases due to sexual transmission from the period before 2000 (26.4%) to between 2000 and 2009 (65.9%). There was no corresponding increase from 2000 and 2009 to after 2010 (p = .751). HCV genotype 1 was most prevalent at all time periods. The genotype 3 frequency decreased over time (test for trend p < .001), whereas genotype 4, extremely uncommon before 2010, became the second most prevalent genotype from 2010 onward. In HIV-infected individuals in Sao Paulo, Brazil, sexual transmission has replaced IDU as the most frequent mode of HCV acquisition.
Keywords: HIV; coinfection; epidemiology; hepatitis C; transmission.