Expanding "Safe Spaces 4 Sexual Health," a Mobile Van HIV/STI Testing and Care Linkage Strategy, for Black MSM in online spaces - Project Summary Ending the HIV epidemic (EHE) depends on developing innovative, strategic and tailored approaches to HIV diagnosis, treatment and prevention. While new HIV diagnoses have declined significantly from their peak, progress has stalled, particularly among Black men who have sex with men (MSM) who remain disproportionately affected in the US. In the pilot study, Safe Spaces 4 Sexual Health (SS4SH), we demonstrated the feasibility and acceptability of a status-neutral HIV/STI testing approach which identified at- risk MSM in online spaces and linked them to testing services on a mobile van in Baltimore, MD. Focusing on reaching MSM in online spaces who may be missed by traditional seek-test-treat strategies, our pilot reached 151 MSM over 14 months and demonstrated a significantly higher new HIV diagnosis (7% vs. 0.5%, p<0.001) and syphilis positivity rate (10% vs. 0.5%, p<0.001) compared to the standard of care health department (HD SOC) mobile van strategy. SS4SH pilot did not evaluate participants’ linkage to PrEP or HIV care, which are key pillars of the EHE strategy. The objective of this proposed R21 is to expand the pilot study to integrate PrEP and HIV care linkage, evaluate the acceptability and feasibility of this expanded strategy and in a quasi- experimental design, generate preliminary data on the effectiveness of this strategy compared to the HD SOC mobile van. The specific aims are: 1) Using a community-based participatory approach, expand SS4SH to incorporate linkage to PrEP for Black MSM at high risk for HIV acquisition and linkage to HIV care for those living with undiagnosed/unsuppressed HIV, and 2) Using a quasi-experimental design, pilot the expanded SS4SH testing plus care linkage strategy to (1) evaluate the acceptability and feasibility of adding care linkage and (2) generate preliminary data on effectiveness of the expanded SS4SH compared to the HD SOC mobile van as defined by reach, reproducibility of testing outcomes, and care linkage outcome measures. Aim 1 will involve qualitative formative work including focus groups and in-depth interviews with Black MSM and key informant interviews with care linkage stakeholders to explore environmental and patient level barriers to care linkage and develop community engaged linkage strategies to overcome these barriers. A community advisory board (CAB), composed of Black MSM recruited from focus group and interview participants will provide member-checking of the study team’s interpretations of qualitative data and partner with the study team to develop the expansion of SS4SH for care linkage to be implemented during the Aim 2 pilot. In Aim 2, we will recruit MSM (ages 18-49) for mobile van HIV/STI testing/care linkage over 8 months. We will evaluate outcome measures of feasibility and acceptability of providing care linkage and generate preliminary data on the effectiveness of the SS4SH compared to the HD SOC mobile van strategy. The proposed research has the potential to inform public health strategies prioritizing Black MSM and potentially reduce ongoing HIV disparities by reaching both those at risk for acquisition and transmission and linking them to care.