Prioritising Hepatitis C treatment in people with multiple injecting partners maximises prevention: A real-world network study

Objective: To describe an injecting network of PWID living in an isolated community on the Isle of Wight (UK) and the results of a agent-based simulation, testing the effect of Hepatitis C (HCV) treatment on transmission. Method: People who inject drugs (PWID) were identified via respondent driven sampling and recruited to a network and bio-behavioural survey. The injecting network they described formed the baseline population and potential transmission pathways in an agent-based simulation of HCV transmission and the effects of treatment over 12 months. Results: On average each PWID had 2.6 injecting partners (range 0–14) and 137 were connected into a single component. HCV in the network was associated with a higher proportion of positive injecting partners (p = 0.003) and increasing age (p = 0.011). The treatment of well-connected PWID led to significantly fewer new infections of HCV than treating at random (10 vs. 7, p<0.001). In all scenarios less than one individual was re-infected. Conclusion: In our model the preferential treatment of well-connected PWID maximised treatment as prevention. In the real-world setting, targeting treatment to actively injecting PWID, with multiple injecting partners may therefore represent the most efficient elimination strategy for HCV.