AbstractBackgroundIn Canada, hepatitis C virus (HCV) transmission primarily occurs among people who inject drugs (PWID) and people with experience in the prison system bare a disproportionate HCV burden. These overlapping groups of individuals have been identified as a priority populations for HCV micro-elimination in Canada, a country currently not on track to achieve its elimination targets. Considering the missed opportunities to intervene in provincial prisons, this study aims to estimate the population-level impact of prison-based interventions and post-release risk reduction strategies on HCV transmission among PWID in high HCV-burdened Canadian city, Montréal.MethodsA dynamic HCV transmission model among PWID was developed and calibrated to community and prison bio-behavioural surveys in Montréal. The, the relative impact of prison-based testing and treatment or post-release linkage to care, alone or in combination with risk reduction strategies, was estimated from 2018 to 2030, and compared to counterfactual status quo scenario.ResultsTesting and linkage to care interventions implemented over 2018-30 could lead to the greatest declines in prevalence (23%; 95% Credible interval(CrI):17–31%), incidence (20%; 95%CrI: 10–28%), and prevent the most new chronic infections (8%; 95%CrI: 4–11%). Testing and treatment in prison could decrease prevalence, incidence, and fraction of prevented new chronic infections. Combining test and linkage to care with risk reduction measures could further its epidemiological impact, preventing 10% (95%CrI: 5–16%) of new chronic infections. When implemented concomitantly with community-based treatment scale-up, both prison-based interventions had synergistic effects, averting a higher fraction of new chronic infections.ConclusionOffering HCV testing and post-release linkage to care in provincial prisons, where incarcerations are frequent and sentences short, could change the course of the HCV epidemic in Montréal. Integration of post-release risk reduction measures and community-based treatment scale-up could also increase the impact of these interventions.