PROJECT SUMMARY Limited use of HIV services by those at highest risk is one of the primary reasons for continued HIV transmission in sub-Saharan Africa. Identifying and engaging these individuals—particularly the 20% of people living with HIV who are unaware of their status—is a major challenge that is not being met by existing service delivery approaches. Men who purchase sex (MPS) are of particularly high priority because they are twice as likely to be HIV-infected as other men and are inherently challenging to identify and reach with HIV services. The proposed project will take place in the region of Kenya with the highest HIV prevalence and seeks to promote engagement in HIV testing, prevention, and care by MPS. Preliminary data demonstrate that “secondary distribution” of HIV self-tests by women who sell sex (WSS) to their sexual partners is acceptable, feasible, and safe and leads to high male partner testing. However, the use of post–self-test services has seldom been promoted or measured in a secondary distribution model. Our interdisciplinary and experienced team of Investigators will address this key gap. Led by an Early Stage Investigator, this project will use a pair-matched cluster-randomized trial design to test an innovative, well-targeted HIV self-test secondary distribution intervention to promote uptake of HIV services by MPS. Clusters served by Ministry of Health–supported HIV clinics will be randomized to receive the secondary distribution intervention or standard of care. In intervention clusters, we will recruit WSS from key population clinics and transactional sex “hot spots.” WSS will be provided with oral fluid–based HIV self-tests and encouraged to distribute them to their male transactional sex partners. Self-test kits will include salient information for men on clinic location and hours within their cluster, and pilot-tested messaging on the importance of early ART initiation, and the availability and benefits of PrEP. In Aim 1, we will evaluate programmatic data from HIV clinics in study clusters to objectively determine the intervention’s impact on uptake of confirmatory testing, ART initiation, and PrEP initiation by men. In Aim 2, we will conduct a process evaluation to characterize factors influencing intervention effectiveness. We will assess secondary distribution patterns and characterize the MPS population receiving self-tests through quantitative program data and a follow-up questionnaire among enrolled WSS. We will use qualitative data obtained through in-depth interviews with MPS to explore pathways and contextual factors influencing whether they accessed post-test services. In Aim 3, we will compute the incremental cost-effectiveness of our intervention to inform decisions about broader implementation. This project has the potential to break new ground on ways to engage high-risk and hard-to- reach populations in HIV services. If effective, our approach could be readily adapted to other settings and help...