The Integrated Female Sexually Transmitted Infection Testing for HIV Epidemic Control Through PrEP (IN-STEP) Study

Globally, new HIV infections are concentrated in eastern and southern Africa and are largely acquired by women outside of known key populations. Identifying African women at highest risk for HIV acquisition and successfully engaging them in HIV prevention services, particularly pre-exposure prophylaxis (PrEP) programs, is an urgent global health priority. The U.S. President's Emergency Plan for AIDS Relief (PEPFAR) programs in Africa typically rely on self-reported risk screening tools (SRST) to target HIV testing and refer individuals for PrEP. However, these tools often perform poorly in validation studies, missing many women at high-risk for HIV acquisition. This is partly due to underreporting of risk factors, but also because many African women are at heightened HIV risk solely through monogamous relationships with high-risk male partners (i.e., network-based risk). Moreover, even among those African women referred and enrolled into PrEP programs, the vast majority stop using PrEP within several months of initiation. While PrEP discontinuation has been linked to various factors, lack of self-perceived HIV risk has been identified as a major barrier to PrEP use among cis-gender African women.

Here, the investigators hypothesize that compared to SRST alone, SRST integrated with diagnostic testing for curable sexually transmitted infections (cSTI) will increase PrEP use (uptake, adherence, and persistence) among cis-gender African women. The investigators further hypothesize that this increased PrEP use will occur through two primary mechanisms: (1) improved identification of women at high risk for HIV via objective biomarker screening, and (2) enhanced self-perceived HIV susceptibility among women with cSTIs. Decades of research has shown strong and consistent links between cSTIs and female HIV acquisition risk, but cSTI testing and treatment has been largely omitted from African HIV programs, partly due to lack of affordable cSTI diagnostics and laboratory capacity. In addition to being risk factors for HIV acquisition, cSTIs are also a significant cause of female reproductive morbidity, still birth, and neonatal morbidity and mortality. With the advent of lower cost multiplex cSTI testing and point of care diagnostics, there is new opportunity to determine whether integrated female cSTI testing can improve HIV epidemic control.

To test the central hypothesis, the investigators will conduct an individually randomized effectiveness implementation trial of SRST plus cSTI diagnostic testing for chlamydia, gonorrhea, trichomonas, and syphilis compared to SRST alone to increase PrEP use among cis-gender African women aged 15 to 39 years. The investigators preliminary observational data suggest that there is a high burden of undiagnosed cSTIs among African women at high risk for HIV and that adding cSTI diagnostic testing to existing PrEP eligibility screening efforts would nearly double the number of PrEP eligible women. Preliminary data also show women with cSTI symptoms are more likely to perceive themselves as being at high HIV risk, and that women diagnosed with cSTIs are more likely to use PrEP. The trial will be nested within the Rakai Community Cohort Study (RCCS), a population-based HIV surveillance cohort in the Lake Victoria basin of Uganda in Eastern Africa, a region with among the highest female HIV case burdens worldwide. Using a population-based design, the investigators will be able to determine what groups and in what programmatic settings cSTI testing would yield the greatest benefit for HIV epidemic control and overall population health. Specific aims are:

1. To conduct an individually randomized effectiveness implementation trial of SRST plus cSTI testing to increase PrEP use among African women at high HIV risk. ~4,500 HIV-negative women will be randomized 1:1 to PrEP eligibility screening based on SRST plus cSTI testing (intervention) versus screening based on SRST alone (control arm). Primary outcomes will be PrEP uptake after screening and adherence and persistence at 6 months assessed through survey, clinical records, and drug level testing.
2. To perform a mixed-methods, implementation science evaluation of female cSTI testing for improving PrEP use for HIV prevention. Guided by the Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) framework, the investigators will use qualitative and quantitative methods to assess the mechanisms, barriers, and facilitators to improving PrEP outcomes through cSTI testing and how this varies by cSTI pathogen, SRST outcomes, and demographic profiles. Implementation science-focused modules will be added to the RCCS. In-depth qualitative interviews will be conducted at 1 and 6 months on a sample of participants after screening in both study arms.
3. To determine the most efficient, population-level female cSTI testing strategies to reduce HIV incidence in African settings. The investigators will use data and results from Aims 1 and 2 to inform mathematical models which will evaluate different cSTI testing approaches to reduce HIV incidence at a population level by considering what cSTIs to screen for, in what health care settings, and at what cost thresholds.

IMPACT: The proposed research will provide a novel and rigorous understanding of whether integrated cSTI diagnostic testing can facilitate female PrEP use in order to reduce HIV incidence through the identification of underserved women at high risk for HIV acquisition and enhancement of their self-perceived HIV susceptibility. Study results will provide actionable, Randomized Controlled Trial (RCT) level, and population-level information to inform strategic delivery of high impact HIV prevention interventions through integrated HIV and cSTI programming.