Theme: Epidemiology & Public Health Research Year: 2015
People who inject drugs (PWID) exhibit high rates of incarceration and Hepatitis C virus (HCV) infection. Hence, prison may be an ideal location for HCV treatment programmes. We project the population prevention benefit of scaling-up levels of HCV interferon-free direct-acting antiviral treatments (DAAs) in prison on the HCV Epidemiology & Public Health Researchdemic among PWID in Scotland.
We develop a dynamic model of incarceration and HCV transmission amongst current PWID, parameterized with national bio-behavioral surveys conducted among community PWID and prisoners, and prison treatment data. The model was calibrated to HCV incidence (17/7% in 2008 for recent(5yrs) community PWID, respectively, 3% for incarcerated PWID in 2010) and antibody prevalence (37/69% in 2008 for recent/non-recent community PWID, respectively, 53% for incarcerated PWID in 2010). We model estimated increases in HCV treatment for PWID from 2008-2014 (from 20/138 to 77/214 in prison/community annually) with PEG/RBV (61/63% SVR in prison/community). We project the 15-year impact on overall PWID HCV chronic(RNA+) prevalence of current and scaled-up prison DAA treatment (90% SVR;12wks), assuming 4-weeks referral from incarceration to treatment, whilst restricting treatment to PWID with sentences >16wks (42% of incarcerated PWID).
The model suggests existing levels of HCV treatment amongst PWID with DAAs could achieve a 46% relative chronic prevalence reduction by 2030, 33% of this impact due to within-prison treatments. Doubled prison treatment rates could achieve a 55% relative chronic prevalence reduction by 2030 (79% greater impact compared to community treatment only). A 70% relative prevalence reduction could be achieved if 90% of chronic PWID prison entrants with sufficient sentence lengths are treated (345 in 2015; declines over time).
Scaling-up HCV treatment rates in prison could provide an important prevention benefit to PWID in the community, and could act as a feasible strategy for undertaking widespread HCV treatment as prevention in many settings.