7. PROJECT SUMMARY This project collaborates with the New York City Department of Health and Mental Hygiene (NYC DOHMH) to develop and test a field-based comprehensive sexual health intervention for HIV-exposed contacts notified by its Partner Services (i.e., HIV contact tracing) program. Individuals reached by PS programs are highest priority for linkage to HIV prevention/care services: 10-20% are newly diagnosed with HIV as a result of PS notification and the remainder are eligible and high priority for PrEP. Because they seek out highest-risk individuals in the field, PS programs have the potential to significantly reduce existing disparities in PrEP uptake and timely HIV care initiation by reaching populations that are currently under-engaged by traditional PrEP or HIV testing programs. The new Partner Services-Sexual Health (PS-SH) intervention offers a comprehensive sexual health package that includes HIV testing, STI testing, ARV/PrEP education and immediate medication start to all individuals receiving contact notification (i.e., being notified of a recent exposure to HIV). NYCDOHMH is collaborating on this research project to enable a scientifically rigorous test of the intervention’s efficacy and produce the highest quality data on implementation dynamics, cost-effectiveness, and affordability to inform dissemination and adaptation of the intervention, should it prove effective. The specific aims are to: (1) Pilot and refine a field-based comprehensive sexual health intervention delivered through the NYC DOHMH Partner Services Program. Under this aim, we will pilot the intervention in five highest prevalence NYC neighborhoods for 6-months (n = ~60), examine feasibility and acceptability, and refine the intervention process and protocols for the trial to test effectiveness at scale. (2) Examine the effectiveness of the Partner Services-Sexual Health (PS-SH) intervention in improving rates of HIV testing, linkage to HIV prevention/care, and PrEP uptake among highest risk contacts recently exposed to HIV. Under this aim, we will conduct a cross-sectional stepped wedge cluster randomized trial in which 12 clusters of NYC neighborhoods are exposed to the intervention sequentially, with three clusters moving from control to intervention every 6 months (n = 1150). Primary outcomes are HIV testing, timely PrEP/ARV uptake, and linkage to PrEP/HIV care. Secondary outcomes are STD testing and receipt of STD treatment (if indicated). (3) Conduct preliminary analyses of economic outcomes, including cost-allocation and affordability to allow other jurisdictions to make decisions about implementation. These analyses will include per-outcome cost-estimates, and will develop a blueprint for economic evaluation of the intervention including incremental cost-effectiveness and budget impact analyses for application locally and nationally. The proposed project is poised to have a significant and sustained impact on the field by: a) addressing a critical gap in the prevention/care continuum to reduce persistent disparities in the epidemic; and b) pioneering a collaborative implementation science approach to accelerate the dissemination of evidence-based practice models across the United States and internationally.

8. PROJECT NARRATIVE Severe disparities in PrEP access and uptake remain among populations most strongly impacted by the HIV epidemic. These same populations suffer from disproportionately high rates of undiagnosed infection and late treatment initiation that translate into high levels of HIV-related mobility and mortality. This implementation science project partners with a public health department to pioneer and rigorously test an innovative method for reaching highest risk populations and engaging them in HIV testing, PrEP, and/or ARV treatment to significantly positively impact the epidemic.