Scaling up HCV prevention and treatment interventions in rural USA - model projections for tackling an increasing epidemic
BACKGROUND AND AIMS: Effective strategies are needed to address dramatic increases in hepatitis C virus (HCV) infection among people who inject drugs (PWID) in rural settings of the United States (US). We determined the required scale-up of HCV treatment with or without scale-up of HCV prevention interventions to achieve a 90% reduction in HCV chronic prevalence or incidence by 2025 and 2030 in a rural US setting.
DESIGN: An ordinary differential equation model of HCV transmission calibrated to HCV epidemiological data obtained primarily from a HIV-outbreak investigation in Indiana.
SETTING: Scott County, Indiana (population 24,181), USA, a rural setting with negligible baseline interventions, increasing HCV epidemic since 2010, and 55.3% chronic HCV prevalence amongst PWID in 2015 PARTICIPANTS: PWID MEASUREMENTS: Required annual HCV treatments per 1000 PWID (and initial annual percentage of infections treated) to achieve a 90% reduction in HCV chronic prevalence or incidence by 2025/30, either with or without scaling-up syringe service programs (SSPs) and medication-assisted treatment (MAT) to 50% coverage. Sensitivity analyses considered whether this impact could be achieved without retreatment of reinfections, and whether greater intervention scale-up was required due to the increasing epidemic in this setting.
FINDINGS: To achieve a 90% reduction in incidence and prevalence by 2030, without MAT and SSP scale-up, 159 per 1000 PWID (initially 25% of infected PWID) need to be HCV-treated annually. However, with MAT and SSP scaled-up, treatment rates are halved (89 per 1000 annually or 15%). To reach the same target by 2025 with MAT and SSP scaled-up, 121 per 1000 PWID (20%) need treatment annually. These treatment requirements are 3-fold higher than if the epidemic was stable, and the impact targets are unattainable without retreatment.
CONCLUSIONS: Combined scale-up of hepatitis C virus (HCV) treatment and prevention interventions is needed to decrease the increasing burden of HCV incidence and prevalence in rural Indiana, USA, by 90% by 2025/30.