Seroprevalence and risk factors of syphilis coinfection in people living with HIV

Objectives: This study aimed to determine syphilis coinfection prevalence in people living with HIV (PLHIV) and risk factors for coinfection. Methods: This single-center retrospective cohort study screened PLHIV who were monitored in our center between March 2000 and February 2020 via the hospital’s database and analyzed them by grouping as TPHA-positive and TPHA-negative. TPHA positivity was considered as indicative of Treponema pallidum exposure. Results: The study included 474 PLHIV of whom median age (IQR) was 37 (30-47), and 429 (90.5%) were male. Of the male participants, 206 (47.9%) were MSM. The syphilis coinfection rate was 30.2% (143/474). Among the participants with syphilis coinfection, 80 (16.9%) were found to be coinfected with syphilis at the time of their HIV diagnosis, while 63 (13.3%) got infected with syphilis at a median (IQR) time of 60 (36-84) months into their HIV follow-up and treatment. Syphilis coinfection was related to being male (p<0.001), MSM (p=0.008) and single (p=0.007). Regular condom use was inversely related to syphilis coinfection (p=0.002). Conclusion: HIV and syphilis have similar transmission routes, and HIV and syphilis coinfection is common among men, MSM and people who do not use condoms. PLHIV should be tested regularly for syphilis and informed about risky sexual behaviors and protection methods. Abstract