Prevention Ambassadors: an HIV self-testing intervention to promote HIV service engagement in the networks of SSP clients

100.7 PROJECT SUMMARY ABSTRACT Amidst the ongoing opioid and polysubstance use epidemics, HIV transmission attributed to injection drug use is threatening decades of HIV prevention progress in the United States. HIV testing and subsequent engagement in HIV prevention and care services are suboptimal among people who inject drugs (PWID) due to multilevel barriers including low healthcare utilization, stigma, homelessness, and limited transportation. HIV self-testing (HIVST) is a discreet, convenient, and empowering HIV testing strategy with great potential to increase HIV testing coverage among PWID. Syringe service programs (SSPs), which successfully promote the secondary distribution (i.e., peer delivery) of sterile syringes, naloxone, and other harm reduction supplies, are uniquely poised to increase the reach of HIVST into the social networks of their clients (i.e., PWID). Leveraging our existing partnership with the Inland Empire Harm Reduction (IEHR) SSP in the Ending the HIV Epidemic (EHE) priority jurisdiction of Riverside County (RC), California, this project seeks to develop and evaluate the “Prevention Ambassadors” (PA) intervention to promote HIV testing and engagement in HIV prevention and care services among PWID via the secondary distribution of HIVST kits with local HIV service information and referrals to HIV service navigation (hereafter “HIVST plus information/referrals”) in the social networks of SSP clients. This novel intervention, informed by the Diffusion of Innovations (DOI) theory, adapts effective social network-based HIV prevention interventions for PWID to extend IEHR’s secondary distribution of sterile syringes and naloxone (i.e., IEHR standard of care; SOC) to include HIVST plus information/referrals. In this two-phase project, we will first engage in an iterative process with PWID and SSP/HIV service providers in RC to adapt, pretest, and refine PA to train PWID (indexes) to distribute HIVST plus information/referrals to other PWID in their social networks (peer-recruits; AIM 1). Next, we will pilot PA with 50 indexes randomized 1:1 to PA or SOC to examine the preliminary effect of PA (vs. SOC) on indexes’ and ~100 peer-recruits’ HIV testing and HIV service engagement outcomes (linkage to PrEP/HIV care, PrEP/ART uptake; AIM 2); explore whether individual and social network characteristics modify the effects of PA (AIM 3); and explore PA acceptability, feasibility, and areas for refinement among indexes, peer-recruits, and local SSP/HIV service providers using a mixed-methods approach (AIM 4). Outcomes will be assessed via surveys, medical records, and qualitative interviews. Findings will support a future R01 efficacy trial and potential PA dissemination to other SSPs nationally to accelerate efforts to end the HIV epidemic among PWID.