Incidence of hepatitis C virus infection and associated determinants among men who have sex with men without HIV in Amsterdam, the Netherlands, between 2012 and 2021.

Objective: To assess the hepatitis C virus (HCV) prevalence, incidence, and associated determinants among men who have sex with men (MSM) without HIV in Amsterdam, the Netherlands.

Methods: We used data from the Amsterdam Cohort Studies (2012-2021) to calculate the prevalence of past/current HCV infection at the first study visit and incidence rate of primary HCV infection during follow-up. We identified determinants associated with incident HCV infection using univariable Bayesian exponential survival models. Phylogenetic analysis was conducted to compare HCV sequences of MSM without HIV to those from MSM with HIV and those using HIV pre-exposure prophylaxis.

Results: A total of 926 MSM were included. At first visit, 2/926 (0.2%) had a past/current HCV infection. Among 891 participants contributing to 6083.30 person-years of follow-up, three incident HCV infections were observed (incidence rate = 0.05/100 person-years). These infections were observed between 2014 and 2018, and all participants had never used HIV pre-exposure prophylaxis. Incident infections were associated with receptive condomless anal sex, having 1-10 sexual partners vs. none, recent injecting drug use (IDU), ever IDU, and fisting, albeit there was substantial uncertainty for all determinants (i.e. 95% credible intervals included one). Phylogenetic analysis revealed that one HCV-RNA sequence was closely related to HCV sequences from MSM with HIV.

Conclusion: While HCV infection is uncommon among MSM without HIV, the risk of infection seems to increase among those with specific behaviors. HCV screening for MSM without HIV should be focused on those reporting these behaviors.