Trends in hepatitis C virus seroprevalence and associated risk factors among men who have sex with men in Montréal: Results from three cross-sectional studies (2005, 2009, 2018)

Abstract

Objectives To eliminate the hepatitis C virus (HCV) by 2030, Canada must adopt a microelimination approach targeting priority populations, including gay, bisexual and other men who have sex with men (MSM). Accurately describing HCV prevalence and risk factors locally is essential to design appropriate prevention and treatment interventions. We aimed to estimate temporal trends in HCV seroprevalence between 2005 and 2018 among Montréal MSM, and to identify socioeconomic, behavioural and biological factors associated with HCV exposure among this population. Methods We used data from three cross-sectional surveys conducted among Montréal MSM in 2005 (n=1795), 2009 (n=1258) and 2018 (n=1086). To ensure comparability of seroprevalence estimates across time, we standardised the 2005 and 2009 time-location samples to the 2018 respondent-driven sample. Time trends overall and stratified by HIV status, history of injection drug use (IDU) and age were examined. Modified Poisson regression analyses with generalised estimating equations were used to identify factors associated with HCV seropositivity pooling all surveys. Results Standardised HCV seroprevalence among all MSM remained stable from 7% (95% CI 3% to 10%) in 2005, to 8% (95% CI 1% to 9%) in 2009 and 8% (95% CI 4% to 11%) in 2018. This apparent stability hides diverging temporal trends in seroprevalence between age groups, with a decrease among MSM <30 years old and an increase among MSM aged ≥45 years old. Lifetime IDU was the strongest predictor of HCV seropositivity, and no association was found between HCV seroprevalence and sexual risk factors studied (condomless anal sex with men of serodiscordant/unknown HIV status, number of sexual partners, group sex). Conclusions HCV seroprevalence remained stable among Montréal MSM between 2005 and 2018. Unlike other settings where HCV infection was strongly associated with sexual risk factors among MSM, IDU was the pre-eminent risk factor for HCV seropositivity. Understanding the intersection of IDU contexts, practices and populations is essential to prevent HCV transmission among MSM.