Model projections on the impact of HCV treatment in the prevention of HCV transmission among people who inject drugs in Europe

Background & Aims: Prevention of hepatitis C virus (HCV)transmission among people who inject drugs (PWID) is criticalfor eliminating HCV in Europe. We estimated the impact of currentand scaled-up HCV treatment with and without scaling upopioid substitution therapy (OST) and needle and syringe programmes(NSPs) across Europe over the next 10 years.Methods:We collected data on PWID HCV treatment rates,PWID prevalence, HCV prevalence, OST, and NSP coverage from11 European settings. We parameterised an HCV transmissionmodel to setting-specific data that project chronic HCV prevalenceand incidence among PWID.Results: At baseline, chronic HCV prevalence varied from <25%(Slovenia/Czech Republic) to >55% (Finland/Sweden), and <2%(Amsterdam/Hamburg/Norway/Denmark/Sweden) to 5% (Slovenia/Czech Republic) of chronically infected PWID were treatedannually. The current treatment rates using new direct-actingantivirals (DAAs) may achieve observable reductions in chronicprevalence (38–63%) in 10 years in Czech Republic, Slovenia,and Amsterdam. Doubling the HCV treatment rates will reduceprevalence in other sites (12–24%; Belgium/Denmark/Hamburg/Norway/Scotland), but is unlikely to reduce prevalence inSweden and Finland. Scaling-up OST and NSP to 80% coveragewith current treatment rates using DAAs could achieveobservable reductions in HCV prevalence (18–79%) in all sites.Using DAAs, Slovenia and Amsterdam are projected to reduceincidence to 2 per 100 person years or less in 10 years. Moderateto substantial increases in the current treatment rates arerequired to achieve the same impact elsewhere, from 1.4 to 3times (Czech Republic and France), 5–17 times (France, Scotland,Hamburg, Norway, Denmark, Belgium, and Sweden), to200 times (Finland). Scaling-up OST and NSP coverage to 80%in all sites reduces treatment scale-up needed by 20–80%.Conclusions: The scale-up of HCV treatment and other interventionsis needed in most settings to minimise HCV transmissionamong PWID in Europe.Lay summary: Measuring the amount of HCV in the populationof PWID is uncertain. To reduce HCV infection to minimal levelsin Europe will require scale-up of both HCV treatment and otherinterventions that reduce injecting risk (especially OST and provisionof sterile injecting equipment).