Scaling-up HCV prevention and treatment interventions in rural United States-model projections for tackling an increasing epidemic

Abstract

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. 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 an 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 among 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 programmes (SSPs) and medication-assisted treatment (MAT) to 50% coverage. Sensitivity analyses considered whether this impact could be achieved without re-treatment of re-infections, 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 24.9% 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 14.5%). To reach the same target by 2025 with MAT and SSP scaled-up, 121 per 1000 PWID (19.9%) need treatment annually. These treatment requirements are threefold higher than if the epidemic was stable, and the impact targets are unattainable without retreatment.

Conclusions: Combined scale-up of hepatitis C virus treatment and prevention interventions is needed to decrease the increasing burden of hepatitis C virus incidence and prevalence in rural Indiana, USA, by 90% by 2025/30.

Keywords: Hepatitis C; mathematical modelling; needle syringe programmes; opioid substitution therapy; people who inject drugs; prescription opioid.