Brief Report: Use of Pre-Exposure Prophylaxis to Prevent Rapid HIV Transmission Among People Who Inject Drugs in Rural Counties in the United States: A Modeling Study

Background:Despite recent HIV outbreaks among people who inject drugs (PWID) in nonurban US settings, syringe service programs (SSP) are often inaccessible in these communities. Furthermore, pre-exposure prophylaxis (PrEP) awareness and coverage for PWID is limited. We aimed to model the impact of PrEP on HIV transmission among PWID in a rural setting.Setting:Using a calibrated agent-based model, we simulated HIV transmission in an adult population (n = 14,573 agents) in Scott County, Indiana between 2015 and 2024.Methods:We modeled PrEP eligibility according to CDC guidelines for PWID. PrEP coverage increased by 15% points in the range 10%-70%. Two counterfactual scenarios were modeled: Unrestricted access for PWID and PrEP for SSP attendees. We calculated the number of new HIV infections and number of person-years on PrEP per averted infection.Results:In the status quo scenario, 153 (95% Simulation Interval: 85, 259) new HIV infections occurred among PWID over 10 years. Compared with the status quo, 40% PrEP coverage resulted in 25% fewer HIV infections in the Unrestricted access for PWID scenario and 10% fewer HIV infections in the PrEP for SSP attendees scenario. The PYPAI was 21 and 43 in the Unrestricted access for PWID and PrEP for SSP attendees scenarios, respectively.Conclusion:Our modeling suggests that PrEP provides substantial benefit to PWID in rural US communities, with fewer restrictions on access providing the greatest effect. Control of HIV outbreaks will require expansion of public health interventions that meet the needs of all individuals.