Objective: To investigate the factors associated with syphilis/HIV infection among men who have sex with men (MSM) maintaining a single sexual partner in Shenzhen. Methods: Respondent driven sampling and snowball sampling method were used to recruit MSM receiving voluntary counseling and testing in Shenzhen Rainbow clinic from 2011 to 2016.
Inclusion criteria: 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.
目的： 分析深圳市男男性行为人群（MSM）梅毒和HIV感染情况及影响因素。 方法： 于2011—2016年，在深圳市采用同伴推动抽样法和滚雪球抽样法招募研究对象到深圳市某彩虹门诊接受自愿咨询检测。纳入18岁及以上、自述最近6个月同性肛交性伴数≥1个者，共3 109名。采用一对一问卷调查方法收集其社会人口学特征、HIV检测史、近2年内献血史、药物滥用史、性取向、性角色、既往从事商业性服务工作、既往接受商业性服务史、最近6个月有无女性性伴等。采集静脉血5 ml，检测梅毒和HIV感染情况。比较研究对象最近6个月与女性和男性发生性行为时使用安全套情况；采用多因素非条件逐步logistic回归模型，分析影响研究对象梅毒感染和HIV感染的相关因素。 结果： 3 109名MSM的年龄为（31.49±8.64）岁，其中感染梅毒者为565例（18.17%），感染HIV者为330例（10.61%），梅毒合并HIV感染者为165例（5.31%）；791名（25.44%）MSM报告最近6个月肛交时保持固定单一性伴。保持固定单一性伴的MSM的梅毒感染率较低，OR（95%CI）值为0.64（0.51~0.81）；保持固定单一性伴的MSM的HIV感染率较低，OR（95%CI）值为0.66（0.49~0.90）。 结论： 深圳市MSM中保持固定单一性伴者比例较低，保持固定单一性伴能降低MSM感染梅毒和HIV的风险。.
Keywords: HIV; Homosexuality, male; Sexual partners; Syphilis.