Risk behaviour assessment after hiv pre-exposure prophylaxis in a large cohort in Brazil

Pre-exposure prophylaxis (PrEP) effectively prevents HIV infection, yet challenges persist in assessing behavior changes post-initiation. This study analyzed risk behavior shifts in PrEP users with free access to the public health system in Brazil. In a Brazilian historical cohort of PrEP users from 2018 to 2020, we collected data on the first and last follow-up visits using health service standardized forms of a nationally standardized system. Paired student’s t-test or McNemar’s test were used as appropriated. Of the 34,000 initial individuals, 19,820 attended follow-up visits. The users were mostly men (89%), homosexual, gay or lesbian (72%), white (54%), with more than 12 school years (68%). After adopting PrEP, there was a difference in risk behaviour, with a significant drop in the number of male sexual partners, use of condoms, which dropped from 31.0% to 24.0%, and injectable drug use and alcohol use, as well the use of other substances(all p-values lower than < 0.01). The maintenance of condom use and adherence to safe sex practices among users need to be further addressed. Also, our results point to the need to implement interventions to prevent sexually transmitted infections among PrEP users.