Potential impact of frequent testing for hepatitis C virus among people who inject drugs toward hepatitis C elimination in the United States.

Abstract

Current hepatitis C virus (HCV) guidelines recommend testing at least once in a lifetime for all adults and periodic testing for people with ongoing risk factors. However, the testing frequency required for these populations including people who inject drugs (PWID) remains unknown. We developed a dynamic network model to simulate HCV transmission among PWID via sharing of injection equipment. We simulated different testing frequencies among PWID, paired with a treatment cascade of direct-acting antiviral therapy, and compared their impact on HCV infection prevalence, incidence, and HCV-related deaths over 10 years. We conducted sensitivity analyses on key parameters and assumptions. In the main analysis, testing on average once per six months reduced HCV infection prevalence, incidence, and HCV-related deaths by up to 45%, 37%, and 42%, respectively. In the sensitivity analyses, increased coverage (access and utilization) had the greatest impact on all three outcomes, and reinfection risk after cure had a substantial impact on incidence. Lower transmission risk, higher cessation rate of injection, and longer partnership duration decreased the three outcomes with or without HCV testing. Frequent HCV testing with treatment had a substantial impact on hepatitis C elimination outcomes. However, it alone in the context of current continuum of care among PWID is unlikely to be sufficient to achieving elimination. Improving access to and utilization of hepatitis C care and harm-reduction services among PWID are crucial to achieving elimination.