Hepatitis C Treatment and Behavioral Risk among Men Who Have Sex with Men with HIV: comparing interferon and direct-acting antiviral eras

Background: Little is known about the effect of hepatitis C virus (HCV) treatment on sexual risk behavior among men who have sex with men (MSM) with HIV by treatment type (interferon [IFN]-based vs direct-acting antiviral [DAA]-based).Setting:MSM with HIV and recently acquired HCV infection enrolled in the MSM Observational Study of Acute Infection with hepatitis C (MOSAIC) cohort.Methods:Using data from 2009 to 2018, we evaluated risk behavior through a validated HCV risk score (where ≥2 indicated high risk) and its individual risk behaviors. Levels of risk behavior before, during, and after treatment were modeled for each treatment episode using linear and logistic regression with Generalized Estimating Equations adjusting for DAA availability and number of reinfections.Results:One hundred forty MSM with a median age of 45 years (interquartile range = 40-49) yielded 180 treatment episodes (n = 131 IFN-based, n = 49 DAA-based). Adjusted mean risk score before, during, and after treatment was 2.4 (95% confidence interval [CI] = 2.1 to 2.6), 0.9 (95% CI = 0.8 to 1.0), and 1.7 (95% CI = 1.5 to 1.8), respectively. Before treatment, no differences in mean HCV risk score or proportion of specific behaviors were found between the regimen groups. During treatment, MSM treated with DAAs had a higher average risk score and proportion of receptive condomless anal sex, sharing toys and unprotected fisting than those treated with IFN. After treatment, the proportion sharing straws were significantly higher in MSM treated with DAAs than in MSM treated with IFN.Conclusions:MSM treated with DAAs, compared with MSM treated with IFN, had higher levels of HCV-related risk behavior during treatment. The higher risk of HCV reinfection in the DAA-era underscores the need for ongoing HCV testing and behavioral interventions against HCV.