男男性行为人群双性性行为的发生及影响因素

目的]调查男男性行为者（menwhohavesexwithmen，MSM）中双性性行为的发生情况及艾滋病相关的高危行为发生情况，分析MSM发生异性性行为的原因及影响因素，为减少艾滋病由高危人群向一般人群扩散，更好地开展艾滋病高危行为干预工作提供思路。方法]采用横断面调查研究的方法，于2010年6_12月按年龄段在上海市浦东新区进行分层抽样，对符合入选标准的研究对象进行一对一的问卷调查，收集一般人口学信息、工作生活状况、社交网络与性行为情况、艾滋病相关知识和态度等资料并进行相关的统计描述与分析。结果]共收集有效问卷158份；66．5％（105／158）的MSM来自上海以外省市；17．7％（28／158）的MSM表示自己是双性恋，27．8％（44／158）的MSM表示过去5年和女性有过性活动，差异有统计学意义（x2=4．60，P〈0．05）；和女性有过性活动的MSM人群中最近一次性行为中安全套使用率为80．O％（12／15），最近6个月每次安全套使用率为53-3％（8／15）；非条件logistic回归分析结果表明，影响MSM人群与女性发生性行为的因素有婚姻状况（OR=10．53，95％CI：3．07～36．13）和性取向（OR=82．86，95％CI：16．35-419．86）。结论]MSM人群中的双性恋是将人类免疫缺陷病毒从MSM人群向一般人群扩散的主要人群，一部分男男同性恋由于婚姻原因和女性发生性行为，进一步增加了人类免疫缺陷病毒向一般人群扩散的力度，应从家庭和社会环境的角度加以防治。

Bisexual Behaviors and Related Influencing Factors among Men Who Have Sex with Men

Objective ] To understand occurrence of bisexual behaviors and other acquired immune deficiency syndrome （AIDS） related high-risk behaviors among men who have sex with men （MSM）, to analyze possible causes and influencing factors to provide suggestions for improving intervention against AIDS related high-risk behaviors. Methods ] A cross-sectional survey was conducted to collect information including demographic characteristics, working and living conditions, social networks and sexual behaviors, knowledge and attitude on AIDS among eligible MSM who were interviewed face to face from June to December, 2010. Results ] A total of 158 MSM were eligible subjects according to the screening criteria, among whom 66.5% （105/158） were from regions outside Shanghai. A significant difference was found in the proportions between MSM who reported having sex with female partners in past 5 years （17.7%, 28/158） and MSM who reported to be bisexual （27.8%, 44/158） （;（2=4.60, P〈 0.05）. Among the MSM who had sex with female partners, the rate of consistent condom use in the past 6 months was 53.3% （8/15） and the rate of condom use in last sexual intercourse was 80.0% （12/15）. The non-conditional logistic regression analysis showed that marriage （OR=10.53, 95%CI： 3.07-36.13） and sexual orientation status （OR=82.86, 95%CI： 16.35-419.86） were the significant fdctors that influenced bisexual behaviors among MSM. Conclusion ] Bisexual behavior is a main cause of HIV transmission from MSM to general population. Some MSM having marital sex with female due to pressure from society and family may promote HIV transmission. Social and family supports, therefore, are very important to HIV prevention in MSM.