Theme: Epidemiology & Public Health Research Year: 2018
Background:
Although hepatitis C virus (HCV) infection is both preventable and curable, acquisition
remains high in key populations including people who inject drugs (PWID) and men who
have sex with men. Few studies have examined the independent contribution of
sexuality to HCV infection risk in PWID. This study examines the association between
sexual activity and HCV acquisition among PWID in Montreal.
Methods:
Participants of the open prospective HEPCO cohort (2004-2017) HCV seronegative at
enrolment with >2 visits were eligible. Behavioural questionnaires and HCV antibody
testing were administered at enrolment and follow-up (6-monthly from 2004-2011, 3-
monthly 2011-2017). A five-category time-updating exposure variable was generated to
summarise engagement in any sexual activity (Y/N), any sex work (Y/N), and any samesex partner (Y/N) in the past 6/3 months. Relative time to HCV seroconversion was
examined using Cox regression analyses adjusted for age, gender and injecting risk
behaviours.
Results:
155 of 440 participants [median age 33 years, 18.9% female, 1.4% HIV-positive at baseline]
seroconverted throughout 1306 person years (py) of follow-up (incidence rate: 11.88/100 py
(95% CI: 10.12, 13.87). Incidence rate was lowest among those reporting no recent sex
[8.22 (95% CI: 5.92, 11.12)] and greatest among those reporting sex work with [25.45
(12.92, 45.36)] or without same-sex partner(s) [27.83 (95% CI: 12.92, 52.84)]. In adjusted
Cox regression models, sex work with [aHR 2.07 (95% CI: 1.01, 4.22)] and without samesex partner(s) [aHR 3.15 (95% CI: 1.31, 7.52)] were associated with HCV acquisition
compared with no recent sex. Sexual activity without sex work was not associated with HCV
acquisition, irrespective of partners’ gender.
Conclusion:
In this cohort of PWID, sex work was associated with greater risk of HCV acquisition,
particularly among those reporting only opposite-sex partners. These minority
populations of PWID at heightened risk of HCV acquisition deserve greater attention in
research and prevention.
Disclosure of Interest Statement:
BJ is supported through CanHepC and Fonds de recherche du Québec – Santé (FRQS)
postdoctoral fellowships. NM is supported through CanHepC PhD trainee scholarship. JB is
receiving advisor fees from Gilead Sciences and Merck and a research grant from Gilead
Sciences, outside of this current work. None of the authors have commercial relationships that
may pose a conflict of interest in connection with this work.