CROI 2026: Global Epidemiology and Prevention of HIV and Other Sexually Transmitted Diseases.

At the 2026 Conference on Retroviruses and Opportunistic Infections (CROI), investigators presented updates on the global HIV epidemic. HIV incidence remains high among key populations, including female sex workers, men who have sex with men, people who inject drugs, and transgender women. Testing for recent infections can guide targeted HIV prevention services to interrupt ongoing transmission. In a cohort study of serodifferent couples in Africa, low-level viremia was associated with reduced but nonnegligible risk of HIV transmission. Sociostructural risk factors play a substantial role in driving new HIV transmissions. Several studies described the use of molecular epidemiology to characterize HIV transmission patterns and identify hot spots. Innovative strategies to increase HIV testing are being evaluated. In an oral preexposure prophylaxis (PrEP) study offering choice between daily and on-demand PrEP, HIV incidence was very low with either regimen. Follow-up data from 2 injectable lenacapavir PrEP trials demonstrated continued high efficacy with very rare breakthrough infections. Although awareness of long-acting PrEP is increasing, use remains low across various cohorts. Several studies reported on the use of PrEP in pregnancy, including a pharmacokinetic study showing no dose adjustment needed for long-acting injectable cabotegravir. Interventions to increase PrEP uptake and persistence show promise. A randomized clinical trial of the meningococcal vaccine did not show efficacy in preventing gonorrhea acquisition. Although doxycycline postexposure prophylaxis (doxy-PEP) use is increasing, it remained low among male veterans with a history of a sexually transmitted infection. Several studies reported on the impact of doxy-PEP on antibiotic use.