Community-led chemsex harm reduction programs boost HIV retention in South Africa, other countries | AIDS 2026

Chemsex is the intentional use of psychoactive substances during sex to increase pleasure, decrease stress or prolong the sexual encounter. Examples include alkyl nitrites, colloquially referred to as “poppers,” methamphetamine and ketamine. Because chemsex can be associated with long sessions of unprotected sex and lowered inhibitions, it is associated with sharply elevated HIV risk, particularly for people who inject drugs. People who inject drugs face a risk of HIV acquisition roughly 14 times higher than the general adult population, and studies in Brazil have found chemsex prevalence among men who have sex with men ranging from 27% to almost 70%.

Despite this risk, structured, health-led responses to chemsex remain rare in much of the world, but outreach groups are trying to change that. Several of these groups presented their abstracts today at AIDS 2026, during ‘Chemsex everywhere: Interventions across contexts.’ The session was led by Carolina Coutinho, Ph.D., a scientist and researcher at the National Institute of Infectious Diseases in Rio de Janeiro, Brazil.

São Paulo's outreach at chemsex parties

The first presenter was Eduardo Almeida, from the Federal University of Rio Grande, co-author of ‘Addressing inter-institutional partnerships on combination HIV prevention for chemsex in São Paulo, Brazil.;
The abstract studied the partnership between the nongovernmental organization Centro de Convivência É de Lei and São Paulo's municipal and state governments on a six-month pilot reaching approximately 3,000 people across seven outreach events at chemsex parties. The program distributed 6,000 units of lubricant, 2,000 condoms, 300 combined prevention and safer drug-use kits and 200 HIV self-test kits, alongside a capacity-building workshop for health professionals and public managers. Researchers said the pilot depended on coordinated governance between civil society and public institutions to gain access to these settings and sustain care.

Thailand's iT-REX cohort for transgender women

Akarin Hiransuthikul, M.D., assistant professor at Chulalongkorn University, Bangkok, Thailand, presented ‘Meeting transgender-specific needs: service acceptance and identified needs among Thai trans women engaging in substance use or chemsex (iT-REX study).’ The iT-REX study, run by Thailand's Institute of HIV Research and Innovation, enrolled 63 transgender women who use substances or engage in chemsex and are not living with HIV, with a median age of 31 years. All but two participants completed in-person assessments across substance use, sexual health, mental health and socio-legal domains. Mental health issues were detected in 55.6% of participants, and 69.8% screened positive for stigma or discrimination, though few requested further support for the latter. Most participants, 69.8%, agreed to start or continue PrEP, and more than half of current hormone users requested hormone-level testing.

South Africa's EJAF Chemsex Program

Dawie Nel, the executive director of OUT LGBT Well-Being, presented ‘Improving HIV retention among men who have sex with men who engage in chemsex in South African townships: evidence from the EJAF Chemsex Program community model.’ With support from the Elton John AIDS Foundation, his organization ran a 15-month pilot, plus a no-cost extension through September 2025, in Soweto, Orange Farm and Johannesburg Inner City. Built on the Social Ecological Model, the program combined structured intake, harm reduction, group cognitive behavioral therapy, peer navigation and outreach to eight chemsex houses. Of 127 HIV-positive participants enrolled, 69% were newly diagnosed. Viral suppression reached 88%, and harmful drug use fell from 79% to 57%. Among 81 clients with complete follow-up data, researchers reported statistically significant improvements in anxiety, depression, psychosis, internalized homophobia and suicidal ideation. Retention slipped to 67% by the program's close, which researchers attributed to the shift toward community-based delivery after USAID support ended in March 2025. The authors said lessons from the pilot informed South Africa's national chemsex harm reduction guidelines.

Training programs in Sri Lanka and Malaysia

In Sri Lanka and Malaysia, where chemsex had no structured, health-led response before 2024, researchers with Health Equity Matters and local partners ran training-of-trainers programs for peer outreach workers and community leaders. Mihitha Basnayake, MBBS, presented ‘Breaking the silence: introducing chemsex harm reduction in criminalized Asian settings,’ of which he was a co-author. A five-day course in Sri Lanka trained 20 participants and produced measurable gains in implementation readiness, including improvements in knowledge of harm reduction practices (+54%), chemsex-related risks (+40%), adult education principles (47%) and safer sex strategies, including PrEP (29%). A parallel five-day training in Malaysia reached 10 core team members. Researchers said early engagement with government counterparts was critical to reducing institutional resistance in these criminalized settings and that sustained investment remains a challenge given short-term funding cycles.