Seroincidence Study Among Men Who Have Sex With Men and Transgender Women - The ImPrEP Seroincidence Study

PrEP (pre-exposure prophylaxis) is an effective prevention strategy in which HIV-negative individuals take antiretroviral drugs (tenofovir disoproxil fumarate and emtricitabine - TDF/FTC) to reduce HIV acquisition. Clinical studies have shown that the TDF/FTC combination protects MSM and transgender women against HIV infection. According to the PROUD study, PrEP can decrease the risk of HIV infection among MSM by 86% (90% CI 64-96). The international community recognizes that PrEP can be an additional tool in the framework of a combination prevention package for those most at risk of contracting HIV. Data on HIV incidence among MSM and trans women are largely unknown. In Brazil, Mexico and Peru, data on the incidence of HIV among MSM and trans women are very scarce, limited to small cross-sectional studies.Current methods used to determine HIV-1 incidence have many limitations. These methods include mathematical modeling, retrospective calculations of AIDS case reports, age-based prevalence determinations, and prevalence determinations with multiple rounds of longitudinal surveys to estimate HIV incidence, which require numerous assumptions and inputs and can pose additional challenges in the era of expansion of antiretroviral therapy (ART) and increased survival of HIV-1 infected individuals. On the other hand, prospective longitudinal cohort studies of high-risk individuals can be used to estimate incidence; however, they are often labor-intensive, complex, very expensive, difficult to implement in most countries, and have recruitment biases. Laboratory methods can be unbiased and do not require complicated assumptions and case-by-case weighting. The cross-sectional use of Recent HIV Infection Tests (TRIs) based on biomarkers offers, in principle, accessible, reliable and low risk of bias options for estimating incidence.

Inclusion Criteria:MSM and transgender womenaged 18 years or olderwillingness and ability to sign an informed consent form.Exclusion Criteria:Individuals currently using PrEP, PEP or receiving antiretroviral therapy;Individuals unable to understand the study or who do not agree to sign the consent form;Individuals who are participating in a clinical trial of antiretroviral medication or any investigational product to prevent the acquisition of HIV infection (for example, monoclonal antibodies such as PEP or PrEP)