Doxy-PEP interest, awareness, and use among sexual and gender minorities in Brazil, Mexico, and Peru: findings from a web-based survey

Summary Background: Sexual and gender minorities (SGM) face a disproportionate burden of sexually transmitted infections (STIs) in Latin America. Doxycycline post-exposure prophylaxis (doxy-PEP) is effective in preventing syphilis, chlamydia and gonorrhea among these populations. We explored doxy-PEP awareness, interest and use in Brazil, Mexico and Peru. Methods: Cross-sectional online survey among SGM assigned male at birth (18+ years) recruited on dating apps (Scruff and Grindr) and social media (Instagram and Facebook). Adjusted logistic regression models were used to explore factors associated with doxy-PEP awareness overall and by country. Findings: Among 16,081 participants (Brazil: 10,269; Mexico: 4081; Peru: 1731), 16% reported previous STI diagnosis. Only 37.7% and 7.2% reported doxy-PEP awareness and use, but interest was high (88.3%). Age >30 years (adjusted odds ratio [aOR]:0.88 [95% confidence interval [CI]:0.79–0.98), post-secondary education (aOR: 1.21, 95% CI: 1.08–1.36), 5+ sex partners (aOR: 1.32, 95% CI: 1.20–1.46), stimulant use (aOR: 1.20, 95% CI: 1.07–1.35), ever PrEP use or living with HIV (aOR: 2.76, 95% CI: 2.49–3.06), higher HIV knowledge (aOR per one standard deviation [SD] increase: 1.35, 95% CI: 1.28–1.44), and higher internalized homonegativity (aOR per one SD increase: 0.87, 95% CI: 0.83–0.91) were associated with doxy-PEP awareness. Interpretation: Despite high interest in using doxy-PEP, its awareness and use remain limited among SGM in Latin America. Targeted efforts are crucial to raise awareness, especially among populations with lower education levels, limited HIV knowledge, and those less engaged with existing prevention services. Strengthening educational campaigns and integrating doxy-PEP into public health sexual health programs will be key to ensuring equitable access and reducing STI incidence. Funding: Unitaid, CNPq and FAPERJ.