江苏省南京、苏州、扬州市男男性行为人群HIV感染因素的配比病例对照研究

Factors associated with HIV infection among men who have sex with men in Nanjing, Suzhou and Yangzhou： a 1 ： 4 matched case-control study

目的探讨影响男男性行为人群HIV传播的危险因素。方法采用时间序列病例对照研究的研究方法，病例为江苏省2008年5—7月在南京、苏州、扬州市同时开展的针对男男性行为者（MSM）调查中发现的所有HIV感染者，对照为按照地区的入组时间进行1：4匹配的非感染者。调查问卷以2008年国家男男性行为人群综合防治试点工作问卷为核心并根据当地情况增加一些变量；采用拟合条件logistic回归模型对数据进行单因素和多因素分析。结果调查中共发现62例阳性感染者，对照组匹配248名非感染者。单因素分析显示从未使用安全套、梅毒、性病相关症状及无保护性肛交为HIV感染的危险因素，其OR值分别为5．56（95％CI：1．82～16．96）、2．19（95％CI：1．18～4．05）、2．50（95％CI：1．13～5．50）和3．13（95％CI：1．64～5．98）；通过互联网寻找性伴及性角色为0是感染HIV的保护性因素，其OR值分别为0．47（95％CI：0．22～0．998）和0．67（95％CI：0．23～1．97）。多因素分析显示患梅毒、无保护性肛交、首次性行为年龄大是感染HIV的独立危险因素，其OR值分别为2．28（95％CI：1．05～4．94）、4，16（95％CI：1．63～10．66）、1．11（95％CI：1．04～1．18）；而双性恋为感染HIV的保护性因素（OR=0．41，95％CI：0．18～0．97）。结论梅毒、无保护性肛交、首次发生男男性行为的年龄较大等因素是感染HIV的危险因素，性取向为双性是感染HIV的保护性因素。

Objective This study assessed the main factors associated with HIV infection among men having sex with men（MSM）,in order to provide evidence for future intervention. Methods A case-control study was conducted among HIV cases identified at the MSM survey in Nanjing, Suzhou and Yangzhou cities from May to July in 2008. Each HIV case was matched by 4 HIV negative MSM who participated consecutively right after the HIV case was identified at the same survey, same time and in the same city. A national core MSM survey questionnaire was used with addition of variables of local interest. Fitting conditional logistic regression model was applied for univariate and multivariate analysis. Results During the survey, 62 HIV positive cases were identified and 248 controls were matched. Data from univariate analysis showed that, inconsistent condom use, syphilis infection, self reported sexually transmitted infection（STI） symptoms and/or signs, unprotected anal sex （UAI） were risk factors, with OR values of 5.56（95%CI： 1.82-16.96）, 2.19（95%CI： 1.18-4.05） ,2.50（95%CI： 1.13-5.50） and 3.13 （95 % CI： 1.64-5.98） respectively. Online cruising and receptive anal sex were protective factors with OR values as 0.47（95%CI：0.22-0.998） and 0.67（95% CI： 0.23-1.97）. Through multivariate analysis, it was found that syphilis, age of having experienced first insertive sexual intercourse and UAI were risk factors to HIV transmission, with OR values of 2.28 （95%CI： 1.05-4.94）, 4.16 （95%CI： 1.63-10.66） and 1.11 （95% CI： 1.04-1.18） respectively. Compared with non-anal sex, bisexual （OR=0.41,95%CI： 0.18-0.97） behavior seemed a protected factor. Conclusion Syphilis infection, UAI and self reported STI symptoms and/or signs were risk factors related to HIV transmission while bisexual seemed a protective factor.