MSM同性偶然性行为及影响因素调查

目的了解男男性行为人群（MSM）同性偶然性行为及其影响因素。方法对2009年绵阳市建立的MSM开放性研究队列进行随访调查，对随访不足基线调查样本部分，采用滚雪球采样法，依据队列纳入条件，招募补足调查对象，进行相关行为学和血清学调查。结果在调查的405例中，有偶然性行为的占83．7％（339／405），艾滋病病毒（HIV）确认感染率为7．7％（26／339），新发感染率5．8／100人年（13／224．9）。接受偶然性行为的占36．3％（147／405），53．6％（217／405）不反对也不接受，53．4％（181／339）在性欲未排解时寻找。寻找时先考虑是否看得上的占55．1％（223／405），是否健康的占51．6％（209／405），是否使用安全套的占19．5％（79／405）。寻找偶然性伴时76．1％（258／339）最担心感染上HIV；寻找之前每次准备安全套的占42．5％（144／339），不准备的占9．6％（39／405）；51．9％（176／399）表示会发生无保护肛交。近6个月偶然性行为肛交每次使用安全套的占51．9％（83／160），8．1％（27／335）出现过安全套破损。多因素分析，年龄（OR=0．811-2．786）、职业（OR=3．044-11．847）、寻找性伴场所（OR=0．147）、随身携带安全套（OR=0．250）是偶然性行为的独立影响因素。结论偶然性行为是MSM人群极其普遍的性行为方式，受人口特征及寻找性伴场所等影响，其低保护性和催生的多性伴极大地增加了HIV感染和传播风险。

Analysis of occasional homosexual acts of MSM and related influencing factors

Objective To study occasional homosexual acts of men who have sex with men （MSM）and analyze related Influencing Factors. Methods A survey was conducted in an open MSM cohort established in Mianyang in 2009. Snowball sampling method was used to complement subjects insufficient at baseline according the enrollment criteria of the cohort. The related behavioral and serological investigation was performed. Results Of the 405 peo- ple investigated, 83.7% （339/405） had occasional sexual acts. Human immunodeficiency virus （HIV） infection rate was 7.7%（26/339）, and the new infection rate was 5.8/100 person-years（13/224.9）. About 36.3% （147/405） subjects accepted occasional sexual acts, 53.6% （217/405） remained neutral, and 53.4% （181/339）would seek when their sexual desire could not be released. About 55. 1% （223/405）firstly considered the appearance while looking for an occasional sex partner, 51.6% （209/405）considered healthy condition, and 19.5% （79/405）considered condom use. HIV infection was the major concern in 76.1% （258/339）subjects looking for occasional sex partner, 42.5 % （144/339）prepared condoms before sexual acts, and 9.6 % （39/405） had anal sex without using condoms. The rate of condom use was 51.9 % （83/160）in the last 6 months, and 8.1% （27/335）had a condom break. Multifactors analysis showed that age （OR=0. 811-2. 786）, occupation （OR=3. 044-11. 847）, places finding sex partners （OR=0. 147） and condom carring （OR=0. 250） were independent influencing factors of occasional sexual acts. Conclusions Occasional sexual acts are very common among MSM, and influenced by features of population and places finding sex partners, which may increase the risk of HIV infection due to unprotected sex and multiple sexual partners.