In Brazil, more than 43,000 HIV infections were reported in 2022, with a mortality rate of 4.1 deaths/100,000 inhabitants. Other STIs – such as syphilis, gonorrhea, chlamydia, and viral hepatitis – may occur in association with HIV infection. Some studies observed a significant increase in other STIs after PrEP initiation. Our objective was to evaluate the incidence of STIs among patients seeking PrEP at a tertiary outpatient service. Observational, longitudinal, prospective study from March 2023 to March 2025. We analyzed STI incidence frequencies before PrEP and after medication initiation. Patients with insufficient chart data were excluded. Of 109 patients in follow-up, 11 were excluded for loss to follow-up after the first visit. Among those evaluated, 95% (94/98) were men, 87% (85/98) homosexual, and 85% (83/98) self-declared White. Daily PrEP was used by 93% (91/98), with 81% reporting full adherence (no missed doses during follow-up); mean age was 32.3 years. In the study population, 15% (15/98) had a steady partner living with HIV, and 44% (43/98) had higher education. Only 35% (34/98) reported frequent condom use. Before PrEP, 19% (19/98) reported prior chlamydia/gonorrhea infection; 34% (33/98) had a history and serology compatible with prior syphilis; six reported human papillomavirus (HPV) infection. After PrEP initiation, incident gonorrhea/chlamydia (confirmed by rapid test at visit) occurred in 5% (5/98), and HPV in 1% (1/98). Syphilis incidence was 8% (8/98), with two reinfections. Only one patient reported prior hepatitis C, treated with sustained virologic response. No HIV infections occurred during follow-up. In our study, it was not possible to affirm a relationship between PrEP use and increased STI incidence. Integrated prevention of HIV and other STIs, through counseling on preventive measures and reinforcement at every opportunity, is essential.
Secchi et al. (2026) studied this question.