Syphilis Seroprevalence and Associated Risk Factors in HIV-infected Individuals

Introduction: Syphilis co-infection is common in patients living with human immunodeficiency virus (HIV)/AIDS due to the common route of transmission. In Turkey, both syphilis and HIV seroprevalences have been increasing in recent years. In our study, it was aimed to evaluate the risk factors related to syphilis co-infection in patients with HIV/AIDS who were followed up in our outpatient clinic. Materials and Methods: Newly diagnosed 1057 patients with HIV/AIDS in our clinic between January 2015 and June 2019 were included in the study. Demographic features of the patients, physical examination findings, CD4+ T lymphocyte count, HIV-RNA level, Venereal Disease Research Laboratory and Treponema pallidum hemagglutination assay test results were analyzed retrospectively. Treponema pallidum hemagglutination assay positivity was accepted as an indicator of encountering with T. pallidum which caused syphilis. Results: The mean age of the 1057 HIV-infected patients included in the analysis was 36.03 +/- 11.49; the mean CD4+ T lymphocyte count was 434.5 +/- 255.4/mm(3), 963 (91.1%) of them were male and 41.4% graduated from university. It was found that 573 of the patients (54.3%) were men who had sex with men (MSM). Treponema pallidum hemagglutination assay positivity were detected in 194 (18.3%) of the patients and 190 (97.9%) patients who encountered with T. pallidum were male (p<0.001). It was found that 22% of MSM and 14% of heterosexual patients encountered with T. pallidum (p<0.001). While 90.2% of the patients did not use condoms in each intercourse, 25.1% stated that they only used it with their legal spouse and for contraception. Conclusion: Sexual contact is the most common route of transmission for both HIV and syphilis. The seroprevalence of syphilis is relatively high in HIV-infected individuals. Among HIV-infected individuals, MSM constitute the group with the highest risk of syphilis. Therefore, syphilis should be screened and treated specifically during the diagnosis of HIV infection and in case of high-risk behaviors.