PrEP adopted by the brazilian national health system: What is the size of the demand?

BACKGROUND: Brazil's response to the HIV epidemic now includes free access to preexposure prophylaxis (PrEP) to populations at substantial risk for HIV infection including men who have sex with men (MSM). We used nationally representative demographic, epidemiologic, and surveillance data to offer estimates for the number of MSM at substantial risk for HIV infection who might be eligible and willing to use PrEP in Brazil. METHODS: Starting from the age/sex-stratified population, we calculated the number of men aged 15 to 64 years, in 5-year age groups, and the proportion of those who report sex with other men during their lifetime. We focused on 11 cities (representing all regions) that are responsible for a significant fraction of the HIV burden of the country and used city-specific HIV prevalence estimates to infer the fraction of MSM who are HIV-negative. We then derived the proportion of HIV-negative MSM under substantial risk for HIV infection defined as having unprotected receptive anal intercourse in the 6 months before study participation. Finally, PrEP uptake among the eligible was inferred from the PrEP Brazil study. RESULTS: Our results show that PrEP demand in these 11 cities is of 66,120 men aged 15 to 64 years. When we consider the lower and upper bounds for the available parameters, we find that PrEP demand in these 11 cities might vary from 33,378 to 97,962 men. If PrEP is restricted to those aged 15 to 49 years, demand drops by 20%. PrEP demand varies considerably by city, mostly because of the differences in population size and city-specific HIV prevalence. DISCUSSION: We have shed light on the probable size of PrEP demand in Brazil certain that the incorporation of PrEP as part of Brazil's combination prevention for populations at substantial risk for HIV infection is a necessary challenge. PrEP will not only prevent HIV infections, it will also expand testing among the most vulnerable with the added benefit of offering combination prevention for the uninfected and immediate treatment for those already infected. As such, expected added benefits of PrEP will be earlier linkage to care, prompt treatment initiation leading to health benefits and decreased transmission.