Risk factors associated with prevalent and incident syphilis among an HIV-infected cohort in Northeast China.

Abstract

BackgroundSexually transmitted infections (STIs) increase HIV infectivity through local inflammatory processes. Prevalent and incident STIs among people who live with HIV/AIDS (PLWHA) are indicators of high-risk sexual behaviors and imply potential spread of HIV. Little is known about the prevalence and incidence of concurrent syphilis and associated risk behaviors among PLWHA in China.MethodsA retrospective cohort study was conducted among PLWHA who attended the outpatient clinic of a designated AIDS treatment hospital in Shenyang, China, between March 2009 and May 2013. Physical examinations and syphilis serology were conducted at each visit. A questionnaire on demographic characteristics was also collected.ResultsA total of 1010 PLWHA were enrolled, of whom 77.0% were men who have sex with men (MSM). The baseline syphilis prevalence among PLWHA was 19.8% (95% confidence interval [CI]:17.3–22.3%). During follow-up, 78.3% retained in the cohort, and contributed a median follow-up of 9.4 months (interquartile range: 5.9-18.7 months). Syphilis incidence among PLWHA was 18.7 (95% CI: 15.5–21.8) per 100 person years. Mulitvariate logistic analysis showed that receiving antiretroviral therapy (ART) (adjusted OR [aOR] = 0.48), older age (≥40 years vs. ≤24 years, aOR = 2.43), being MSM (aOR = 2.30) and having higher baseline HIV viral load (>100000 copies/mL vs. ≤100000 copies/mL, aOR = 1.56) were independent predictors for syphilis infection among PLWHA at enrollment (p < 0.05 for all). Mulivariate Cox regression found that receiving ART (adjusted hazard ratio [aHR] = 1.81), older age (≥40 years vs. ≤24 years, aHR: 5.17) and MSM status (aHR = 2.68) were independent risk factors for syphilis seroconversion (each p < 0.05).ConclusionsSyphilis prevalence and incidence were high among PLWHA in Shenyang. A campaign focusing on detection and treatment of syphilis among PLWHA is urgently needed, especially one with a focus on MSM who are at a higher risk for syphilis.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-014-0658-1) contains supplementary material, which is available to authorized users.