Factors associated with syphilis/HIV infection among men who have sex with men in Shenzhen,2011-2016

Abstract

aged 18 years and above; reported having one or more anal sexual partners in the recent 6 months. A total of 3 109 men who have sex with men (MSM) were involved in the study. Questionnaire-based interviews were conducted on a one-on-one basis. Data were collected including socio-demographic information, human immunodeficiency virus (HIV) testing history, history of blood donation and drug abuse in the recent two years, self-identified sexual orientation, role in homosexual behavior, ever being money boys (MB) and clients of MB, female sexual partners in the recent 6 months. 5 ml blood samples were taken after questionnaires. Syphilis was screened using toluidine red unheated serum test for the antibody of treponema pallidum and then confirmed by treponema pallidum particle assay. The enzyme-linked immunosorbent assay (ELISA) was used for screening HIV and western blot was used to confirm the HIV screening results. The difference of condom use among MSM between female sexual partners and male sexual partners were compared. Multivariate unconditional stepwise logistic regression model was used to analyze factors associated with syphilis infection and HIV positive among MSM. Results: A total of 3 109 eligible participants with mean (SD) age of 31.49 (8.64) years were enrolled in this study. Among them, 565 cases were infected with syphilis (18.17%), 330 cases were infected with HIV (10.61%), and 165 cases (5.31%) were syphilis co-infected with HIV. 791 (25.44%) reported maintaining a single sexual partners in the recent 6 months. Compared to MSM with multiple sexual partners, the prevalence of syphilis and HIV infection among MSM with a single sexual partner were lower, and the OR (95%CI) were 0.64 (0.51-0.81) and 0.66 (0.49-0.90), respectively. Conclusion: The proportion of fixed single sexual partner was much lower among MSM in Shenzhen. Maintaining a single sexual partners can reduce the risk of syphilis/HIV infection among MSM.