Resum

Background: Across Europe, sexually transmitted infections (STIs) notifications have reached historical peaks in recent years, particularly men who have sex with men (MSM). People living with HIV (PWH) are at particularly high risk, given overlapping sexual networks, behavioral factors, and biological susceptibility. However, Spanish data describing long-term trends in newly diagnosed PWH remain scarce. Methods: We conducted a retrospective single-center cohort study including all newly diagnosed PWH from 2015–2024 at a hospital in Madrid. Incident STIs were defined as new laboratory-confirmed diagnoses of Treponema pallidum, Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium, and hepatitis C virus (HCV) infection. Each STI episode was counted as an event, allowing multiple events per patient. Incidence rates were calculated as the number of episodes divided by total follow-up time in patient-years (PY). To evaluate temporal changes, we compared the pre- pre-exposure prophylaxis (PrEP) era (2015–2019) with the post-PrEP era (2020–2024), since oral PrEP became available in Madrid at the end of 2019. Future trends were estimated by linear regression. Results: A total of 441 PWH were included (median age 34.6 years; 98.2% cisgender men; all of them MSM; 52.4% Spanish-born), contributing 663 STI episodes. Most episodes were asymptomatic (65.5%). Overall, 189 patients (42.9%) had no STI, 148 (33.6%) experienced 1–2 episodes, and 104 (23.6%) had =3. By pathogen, T. pallidum accounted for 44.1% of episodes, N. gonorrhoeae 22.1%, C. trachomatis 19.3% (with 51.9% lymphogranuloma venereum), M. genitalium 9.7%, and HCV 4.3%. The incidence rate increased markedly over time (Figure 1). Mean incidence during pre-PrEP era was 2.78 per PY compared to 10.71 per PY during post-PrEP, a statistically significant difference (t-test, p=0.002). Linear regression predicted a continued rise: 14.6 (95% CI 10.6–18.6) in 2025, 16.1 (95% CI 11.5–20.6) in 2026, 17.5 (95% CI 12.3–22.7) in 2027, and 18.9 (95% CI 13.1–24.7) in 2028. Conclusions: In this 10-year cohort of PWH, STI incidence increased almost fourfold in the post-PrEP period. Projected trends suggest continued growth, highlighting the urgent need for intensified STI prevention within HIV care