Single-center Bogotá study finds 24.9% STI prevalence among PrEP users

A cross-sectional study of 185 people enrolled in a HIV pre-exposure prophylaxis, or PrEP, program at a single center in Bogotá, Colombia, found that 24.9% were infected with at least one of three genital sexually transmitted infection-associated microorganisms. The result, reported in BMC Infectious Diseases , had a 95% confidence interval of 20.64% to 29.08%. Most infections were asymptomatic, indicating that the absence of reported symptoms did not exclude infection within this population.

The study evaluated participants between July and September 2024, with most—84.8%—using a daily PrEP regimen. Among the 46 participants identified as cases, Ureaplasma urealyticum was the most frequently detected microorganism, accounting for 35 infections, or 76.1% of cases. Chlamydia trachomatis and Neisseria gonorrhoeae each accounted for 19.5% of cases.

These organism-specific percentages describe the distribution of detected infections among the 46 cases, whereas the 24.9% estimate applies to prevalence across all 185 enrolled patients. The researchers conducted univariate and multivariate analyses to identify variables associated with higher infection prevalence and calculated prevalence ratios with 95% confidence intervals. Two reported sexual practices were independently associated with a higher prevalence of infection.

Group sex had a multivariate prevalence ratio of 6.33, with a 95% confidence interval of 2.37 to 18.2 and a p value below 0.001. Fisting was also independently associated with infection, with a prevalence ratio of 2.18, a 95% confidence interval of 1.37 to 3.49 and a p value below 0.001. The confidence intervals for the group-sex estimate were especially broad, indicating substantial uncertainty in the magnitude of that association, although its direction was positive in the reported model.

Clinical management differed by the microorganism detected, according to the study. Participants with N. gonorrhoeae and C. trachomatis received treatment, while cases of U. urealyticum were treated only when symptoms were present. Because asymptomatic infections were the most common presentation in the cohort, symptom-based detection alone would have missed much of the observed prevalence.

The study’s central finding was that the population using PrEP had a substantial burden of infection with all three microorganisms tested, with group sex and fisting independently associated with higher prevalence. The findings should be interpreted as a snapshot from one center rather than a measure of incidence, long-term trends or prevalence across all PrEP users. It therefore cannot establish whether PrEP use itself influenced infection prevalence or whether the observed patterns differ from those in other populations.

The sample size, single-center setting and three-month recruitment period also limit how broadly the results can be generalized. The authors’ conclusion was that regular STI screening and tailored prevention strategies are important in this population, making the study’s high prevalence and frequent asymptomatic infection central concerns for services already reaching people through PrEP programs.

Subject of Research: Cross-sectional assessment of genital STI prevalence and associated factors among 185 PrEP users at one Bogotá center

Article Title: Prevalence and factors associated with genital Chlamydia trachomatis, Neisseria gonorrhoeae and Ureaplasma urealyticum infections among patients in a preexposure prophylaxis (PrEP) program at a single center in Bogotá, Colombia

Article References: Florez, Y. F. M., Bolivar, Z. R., Brochero, C. R. D., Rubio, A. P. G., Rojas, L. T., Coronado, S. O., Dallos, V. V., Guerra, S. A., Diaz, J. S. M., & Beltran, S. L. V. (2026). Prevalence and factors associated with genital Chlamydia trachomatis, Neisseria gonorrhoeae and Ureaplasma urealyticum infections among patients in a preexposure prophylaxis (PrEP) program at a single center in Bogotá, Colombia. BMC Infectious Diseases. https://doi.org/10.1186/s12879-026-13404-5

Image Credits: AI Generated

DOI: 10.1186/s12879-026-13404-5

Keywords: PrEP, sexually transmitted infections, Chlamydia trachomatis, Neisseria gonorrhoeae, Ureaplasma urealyticum, Bogotá, asymptomatic infection, prevalence, group sex, fisting, factors, associated