Background Increasing rates hepatitis C virus (HCV) infection associated with ongoing risk activity have been reported after successful cure or viral clearance. We assessed factors associated with reinfection after treatment-induced or spontaneous clearance (SC) in both HIV-infected and uninfected men who have sex with men (MSM) in British Columbia.

Methods We followed HIV-infected and uninfected MSM who achieved sustained virologic response (SVR) to HCV treatment or had SC with ≥1 subsequent HCV RNA measurement in the British Columbia Hepatitis Testers Cohort. Crude reinfection rates per 100 person-years (PYs) were calculated. Cox regression was used to model adjusted hazard ratios (HRs) and 95% confidence intervals (CI) for reinfection.

Results We identified 1,349 HCV-infected MSM with SVR (n=856) or SC (n=493), of which 349 (26%) were HIV-positive. HIV-infected MSM were more likely to have histories of injection drug use (41% vs 21%), alcohol use (22% vs 14%) and mental health disorders (47% vs 28%), compared to HIV uninfected. A total of 98 reinfections were identified, yielding an overall reinfection rate of 1.9 per 100 PY (1.0 for SVR patients and 2.7 for SC). HIV-infected MSM had higher rates of reinfection (3.1 vs 1.6 per 100 PY) than HIV uninfected individuals. In multivariable analysis, age < 35 years (HR 3.1, 95% CI: 1.2, 8.1), cure through SVR(HR 0.2, 95% CI: 0.1, 0.4), HIV infection (HR 2.0, 95% CI: 1.3, 3.1), problematic alcohol use (HR 2.0, 95% CI: 1.2, 3.3), injection drug use(HR 2.7, 95% CI: 1.6, 4.3) and mental health counseling (HR 0.2, 95% CI: 0.1, 0.4) were independently associated with reinfection. Among HIV-infected, injection drug use (HR 1.9, 95% CI: 0.8, 4.2) was less strongly associated with reinfection.

Conclusion Rates of HCV reinfection remain elevated among HIV-infected and uninfected MSM. Substance use is driving reinfection among HIV-negative MSM, while sexual transmission may be more important among HIV-positive MSM.

Disclosure No significant relationships.