Prevalence and risk factors associated with syphilis in a cohort of HIV positive individuals in Brazil

Individuals with syphilis have higher chance of having HIV, and syphilis' genital ulcers increases HIV transmission rate. Nevertheless, there are few well-documented studies about HIV and syphilis co-infection and its risk factors. The study was based on 2262 HIV infected individuals from South Brazilian HIV cohort, which began in 1991, and this analysis included individuals who were included in the cohort until November 2008. Inclusion criteria were having CD4 + T cell count and viral load at baseline, and syphilis serology tests (venereal disease research laboratory [VDRL] > 1: 64 or a positive VDRL plus a positive treponemal test). A total of 1012 patients were included; 580 were men (57%); mean age at HIV diagnosis was 33 years; 591 (58%) had previous diagnosis of AIDS; most of the individuals acquired HIV from sexual contact (47.9% heterosexual and 31.7% men who had sex with men [MSM]); and 759 (75%) were on antiretroviral therapy. The prevalence of syphilis was 20.5% (208). After multivariate analysis, being male (2.01; 95% CI, 1.23-3.27; p = 0.005) and MSM (1.91; 95% CI, 1.25-2.90; p = 0.002) were significantly associated to HIV and syphilis co-infection. Males and MSM were associated with higher risk of this co-infection. Our findings may reflect that this particular population is still engaging in unprotected sexual intercourse, and efforts should be made to better target this specific group as they might perpetuate these infections.