Risk factors associated with HCV co-infection amongst MSM and transgender women living with HIV in Mexico City: A case-control study

Introduction and objectives: Hepatitis C virus infection (HCV) is a major cause of co-morbidity in people living with HIV (PLWHIV). The modes of HCV transmission in the local population of PLWHIV are still unclear. We conducted this study to identify risk factors for HCV transmission amongst PLWHIV in central Mexico. Material and methods: We enrolled HIV/HCV co-infected cases and HIV controls receiving care in two outpatient clinics in Mexico City. Structured questionnaires were applied, covering demographics, history of percutaneous exposures, sexual behaviors, self-reported STD and recreational drug use. The statistical analysis for between-group comparisons were multivariate logistic regression models to assess the risk factors associated with HCV co-infection. We limited the final analysis to men who have sex with men (MSM) to avoid confounders potentially related to HCV acquisition in other populations. Results: Three hundred and thirty-four MSM with HIV (175 with HCV co-infection and 159 without) were analysed. We did not identify percutaneous exposures as risk factors for HCV. Intravenous drug use (IVDU) occurred in two cases and one control case. Risk factors independently associated with acquiring HCV co-infection were: history of an ulcerative STD (aOR=2.65, 95%CI=1.44-4.88), a HCV positive partner (aOR=5.25, 95%CI=2.78-9.91), having practiced insertive fisting (aOR=2.62, 95%CI=1.01-6.90), and rectal administration of drugs during sex (aOR=2.46, 95%CI=1.25-4.84). Conclusions: Risky sexual behaviors and chemsex seem to be the main drivers of HIV/HCV co-infection amongst PLWHIV in Central Mexico. IVDU and percutaneous exposures have a minor role in the local HCV epidemic. These findings highlight the importance of testing for HCV in sexually active MSMs.