Incidence of sexually transmitted infections and screening models among pre-exposure prophylaxis users.

INTRODUCTION: There is discussion about the frequency of STI screening among pre-exposure prophylaxis (PrEP) users. The aim of this study was to analyse the incidence of STIs and to evaluate different screening models in order to optimise the follow-up. METHODOLOGY: A prospective study was conducted between 2017 and 2023, including 138 PrEP users in a STI clinic. Participants were tested for STIs every three months. Unscheduled visits were performed for those with STI-related symptoms or for people who were notified for an STI by a sexual partner. We performed a survival analysis of repeated events, estimating the cumulative incidence (CI) and incidence rate (IR). RESULTS: The overall CI by quarterly screening was 8.3 (95% CI: 7.6-9.1) infections per person over six years, with a decreasing trend. The most frequently diagnosed pathogen was Neisseria gonorrhoeae, with a IR of 0.76 (95% CI: 0.68-0.84). If the frequency of screening is reduced to every six months, the IR of STIs is reduced by (95% CI: 0.5-0.66) infections per user per year, and at 12 months by 0.82 (95% CI: 0.73-0.89). In the case of no pharyngeal or urethral screening, IR is reduced by 0.37 (95% CI: 0.32-0.42) infections per person per year and in those over 35 years of age by 0.33 (95% CI: 0.25-0.4). Eliminating unscheduled visits, the reduction in IR is 0.33 (95% CI: 0.24-0.42). CONCLUSIONS: The incidence of STIs among PrEP users is high, especially in the rectum, but it does not increase over time. STI screening could be optimised reducing the frequency of pharyngeal and urethral testing, particularly in those over 35 years of age. It is essential to redistribute health resources for unscheduled visits, which have been shown to be the most cost-effective screening.

Low use of condom and high STI incidence among men who have sex with men in PrEP programs.

OBJECTIVE: Since the recent introduction of preexposure prophylaxis (PrEP), several studies have reported a decrease in the use of condoms and a rise in STIs among users. This rise in risk behavior associated with the advent of PrEP is known as "risk compensation." The aim of this study is to measure clinical and behavioral changes associated with the introduction of PrEP by analyzing condom use for anal intercourse, number of sexual partners, sexualized drug use and STI incidence. METHODS: We performed a retrospective descriptive study of PrEP users followed every 3months over a 2-year period spanning 2017-2019 in a referral clinic specializing in STI/HIV in Madrid, Spain. One hundred ten men who have sex with men and transgender women underwent regular screening for STIs and hepatitis C virus (HCV) infection. Sociodemographic, clinical, and behavioral data were gathered for all subjects studied. RESULTS: The risk compensation observed in this study consisted primarily of a lower rate of condom use, while the number of sexual partners and recreational drug consumption remained stable. We observed a very high incidence of STIs in this sample, particularly rectal gonorrhea and chlamydia. The factors shown to be independently associated with the presence of an STI on multivariate analysis were age below 30 years and over 10 sexual partners/month. CONCLUSION: The incidence of STI acquisition was higher than expected, indicating a need for strategies to minimize this impact, particularly among younger individuals with a higher number of sexual partners.

Risk factors associated with sexually transmitted infections and HIV among adolescents in a reference clinic in Madrid.

INTRODUCTION: Adolescents have a higher incidence of sexually transmitted infections (STIs) than persons of older age groups. The WHO emphasises the need to adopt specific and comprehensive prevention programmes aimed at this age group. The objective of this work was to analyse the prevalence of HIV/STIs among adolescents and to identify the sociodemographic, clinical and behavioural markers associated with these infections, in order to promote specific preventive strategies. METHODOLOGY: Retrospective descriptive study of adolescents, aged 10-19 years, who were attended to for the first consultation between 2016 and 2018 in a reference STI clinic in Madrid. All adolescents were given a structured epidemiological questionnaire where information on sociodemographic, clinical and behavioural characteristics was collected. They were screened for human inmmunodeficiency virus (HIV) and other sexually transmitted infections (STIs). The processing and analysis of the data was done using the STATA 15.0 statistical package. RESULTS: The frequency of HIV/STIs detected among all adolescents was: gonorrhoea 21.7%, chlamydia 17.1%, syphilis 4.8% and HIV 2.4%. After conducting a multivariate analysis, the independent and statistically significant variables related to the presence of an STI were having first sexual relations at a young age and having a history of STIs. Latin American origin was just below the level of statistical significance (p = 0.066). DISCUSSION/CONCLUSIONS: Adolescents who begin sexual relations at an early age or those who have a history of HIV/STIs are at higher risk of acquiring STIs. Comprehensive prevention programmes aimed specifically at adolescents should be implemented, especially before the age of 13 years.