Hepatitis C infection risk high in MSM on PrEP

Men who have sex with men (MSM) who are on pre-exposure prophylaxis (PrEP) for HIV are at risk of hepatitis C virus (HCV) infections, a new study has found.

The study included 350 MSM (median age, 40 years) on PrEP who were tested for HCV antibodies or RNA every 6 months. Study outcomes were primary HCV infection, reinfection and possible reinfections, measured separately and defined according to the European Association for the Study of the Liver (EASL) criteria. An infection was considered cured if the patient had sustained virological response ≥12 weeks after the end of treatment.

Over a median cumulative follow-up of 2.0 years (653.6 person-years) at risk, 12 incident HCV infections were recorded along with three possible infections. All 15 events were documented in 14 participants.

Overall, eight primary infections occurred in 333 at-risk MSM over 628.4 person-years of follow-up, while seven reinfections were reported in 21 at-risk participants over 25.2 person-years. Excluding the possible reinfections, the resulting infection and reinfection incidence rates were 1.84 and 16.6 per 100 person-years, respectively.

There were no cases of HIV in those with incident HCV.

Significant risk factors for HCV included condomless anal sex with casual partners in the past 3 months (hazard ratio [HR], 1.57, 95 percent confidence interval [CI], 1.09–2.20), being recently diagnosed with an anal sexually transmitted infection (HR, 2.93, 95 percent CI, 1.24–7.13) and injecting drugs in the past 12 months (HR, 4.69, 95 percent CI, 1.61–12.09).