Risk Factors Associated with Sexually Transmitted Infections among Pre-Exposure Prophylaxis Users in an Urban Multi-Clinic Healthcare System

Abstract

Background. While the effcacy of Pre-Exposure Prophylaxis (PREP) in the prevention of HIV is well established in clinical trials, its utility in clinical practice needs to be defined. In contrast to lifelong HIV treatment, the use of PrEP should be only for those who remain at continued risk of HIV infection. Using sexual transmitted infection (STI) diagnosis as an indicator of continued high-risk sexual behavior, this study aimed to evaluate risk factors associated with STIs in PrEP users in New York City. Methods. This retrospective cohort study included electronic health records of patients who initiated PrEP at Mount Sinai Health System from 2013 to 2016. Patients were screened for syphilis and urethral, rectal and pharyngeal gonorrhea and chla-mydia every 6 months with additional testing at providers' discretion. Results. During the study period, 599 patients (95% male) initiated PrEP at 34.3 years of age on average (SD=9.8; range=17-75). Of the 516 with information on sexual orientation, 91% was MSM; 38% was White, 17 % Hispanic, and 12 % Black. Nearly 35% of the 450 tested for STIs had at least one STI with 9% receiving 3 or more positive results. A total of 278 STIs were detected over 460 person-years of follow-up among 328 patients with a known PrEP initiation date; STI incidence was 59.7/100 person-years (95% CI: 48.68-70.63). There were no significant differences by race or ethnicity. Rectal STIs were significantly higher among those aged 25-30 (P