Latin America is experiencing an increase in the number of new HIV infections among key populations, including in Brazil, despite the country providing pre-exposure prophylaxis (PrEP) in daily oral form through the Unified Health System. Alcohol and other substance use are prevalent among young people, potentially affecting adherence to medication throughout the region.

A study conducted by Carolina Coutinho, from the Evandro Chagas National Institute of Infectious Diseases, Fiocruz, in Rio de Janeiro, and the ImPrEP Study Group*, aimed to examine substance use and its association with adherence to daily oral PrEP among gay, bisexual, and other men who have sex with men (MSM), transvestites, and transgender women seeking HIV prevention services in Latin America. The analysis was presented at the 14th Congress of the Brazilian Association of Collective Health (Abrasco), held from November 28 to December 3 in Brasília.

From 2018 to 2021, the ImPrEP study included HIV-negative individuals over 18 years of age from Brazil, Mexico, and Peru. Participants who took less than 60% of their PrEP pills had inadequate adherence. Alcohol and other substance use was self-reported at each follow-up visit.

In total, 9,509 people were included in the study, of whom 94.8% were MSM and 5.2% were transvestites/trans women, with the majority of the sample (69%) composed of mixed-race individuals and the highest frequency of substance use in Mexico. The most commonly used substances in the three countries were alcohol (64.5%), marijuana (31.9%), poppers (21%), cocaine (11%), and club drugs such as ecstasy, LSD, GHB, and ketamine (12.6%). There were also reports of crack cocaine use (1.2%), solvents (0.9%), and injectable drugs (0.8%).

Cocaine, on a larger scale, binge drinking (excessive alcohol use in a short period), and poppers, on a smaller scale, were associated with inadequate adherence to PrEP. Poor adherence to prophylaxis was higher in Mexico and Peru and among transvestites/transgender women, younger people (18 to 24 years old), and volunteers with lower levels of education.

For the authors, the association between substance use and PrEP adherence among MSM, transvestites, and transgender women varied according to the type of substance and the local context, considering legislation and availability. They emphasize that the findings of this study reinforce the importance of integrating mental health and harm reduction services into HIV prevention strategies.

*Authors:

Carolina Coutinho (1), Hamid Veja (2), Mayara Secco (1), Brenda Hoagland (1), Marcos Benedetti (1), Ronaldo Ismério (1), Valdiléa Veloso (1), Beatriz Grinsztejn (1), Thiago Torres (1) and ImPrEP Study Group

(1) Evandro Chagas National Institute of Infectology, Fiocruz), Rio de Janeiro, Brazil

(2) Ramon de La Fuente Muñiz Institute of Psychiatry, Mexico City, Mexico.