Abstract：
BACKGROUND: 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.
METHODS: 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.
METHODS: 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.
摘要：
背景：有关于暴露前预防（PrEP）使用者中STI筛查频率的讨论。这项研究的目的是分析性传播感染的发生率并评估不同的筛查模型，以优化随访。
方法：在2017年至2023年之间进行了一项前瞻性研究，其中包括在STI诊所的138名PrEP使用者。每三个月对参与者进行性传播感染测试。对于有性传播感染相关症状的人或性伴侣通知性传播感染的人，进行了计划外的访问。我们对重复事件进行了生存分析，估计累积发病率(CI)和发病率(IR)。
结果：每季度筛查的总CI为6年中每人8.3（95％CI：7.6-9.1）感染，呈下降趋势。最常诊断的病原体是淋病奈瑟菌，IR为0.76（95%CI：0.68-0.84）。如果筛查频率减少到每六个月一次，性传播感染的IR降低了(95%CI：0.5-0.66)每年每位用户的感染，12个月时为0.82（95%CI：0.73-0.89）。在没有咽部或尿道检查的情况下，IR降低了每人每年0.37（95％CI：0.32-0.42）感染，而35岁以上的人则降低了0.33（95％CI：0.25-0.4）。消除计划外的访问，IR的降低为0.33(95%CI:0.24-0.42)。
结论：PrEP使用者的性传播感染发生率很高，尤其是在直肠,但它不会随着时间的推移而增加。可以优化STI筛查，减少咽部和尿道检查的频率，尤其是35岁以上的人群。必须为计划外的访问重新分配卫生资源，这已被证明是最具成本效益的筛查。
方法：在2017年至2023年之间进行了一项前瞻性研究，其中包括在STI诊所的138名PrEP使用者。每三个月对参与者进行性传播感染测试。对于有性传播感染相关症状的人或性伴侣通知性传播感染的人，进行了计划外的访问。我们对重复事件进行了生存分析，估计累积发病率(CI)和发病率(IR)。
结果：每季度筛查的总CI为6年中每人8.3（95％CI：7.6-9.1）感染，呈下降趋势。最常诊断的病原体是淋病奈瑟菌，IR为0.76（95%CI：0.68-0.84）。如果筛查频率减少到每六个月一次，性传播感染的IR降低了(95%CI：0.5-0.66)每年每位用户的感染，12个月时为0.82（95%CI：0.73-0.89）。在没有咽部或尿道检查的情况下，IR降低了每人每年0.37（95％CI：0.32-0.42）感染，而35岁以上的人则降低了0.33（95％CI：0.25-0.4）。消除计划外的访问，IR的降低为0.33(95%CI:0.24-0.42)。
结论：PrEP使用者的性传播感染发生率很高，尤其是在直肠,但它不会随着时间的推移而增加。可以优化STI筛查，减少咽部和尿道检查的频率，尤其是35岁以上的人群。必须为计划外的访问重新分配卫生资源，这已被证明是最具成本效益的筛查。
