Insights into Hepatitis C Transmission in Young Persons who Inject Drugs: Results From a Dynamic Modeling Approach Informed by State-Level Public Health Surveillance Data

Abstract

Rising use of heroin and prescription opioids are major contributors to increases in Hepatitis C Virus (HCV) incidence in US young adults since the late 1990s. How best to interrupt transmission and decrease HCV prevalence in young persons who inject drugs (PWID) is uncertain, but modeling studies in older populations support interventions that increase HCV treatment among all PWID. We developed a transmission model of young (aged 15-30 years) PWID, which we fit to state-level US HCV surveillance data, and simulated the potential impact of primary (reducing injection initiation), secondary (increasing cessation, reducing injection partners, or reducing injection drug use relapse), and tertiary (HCV treatment) interventions on incident and prevalent HCV cases. Interventions with primary prevention initiatives (reducing injection initiation) yielded concurrent reductions to HCV incidence and prevalence. Treatment of former PWID led to prevalence reductions but did not reduce incidence. Treatment of current and former PWID without other interventions led to incidence reductions in scenarios with high injection initiation rates, high syringe sharing, and low relapse rates after injection cessation. While these results are specific to Michigan, our approach could be applied in other states conducting HCV surveillance to identify local-level intervention opportunities.