年轻男男性行为者的家庭社会经历及其自认同性性行为成因的关联因素

目的了解年轻男男性行为者(YMSM)的家庭社会经历,分析其同性性行为成因的关联因素。方法采用"滚雪球"抽样法,选取2016年9月至2019年9月绵阳市338名YMSM进行家庭社会经历及成因等问卷调查。结果有效问卷338份,家里强势方为父亲的占38.8%、母亲的占48.2%,最崇拜家人是父亲的占23.7%、母亲的占46.2%。进入男男性行为者(MSM)前,32.5%交过女朋友,40.3%身边有关系较好MSM同伴。自认MSM先天形成的占71.0%,后天形成的占29.0%;后天形成17.3%因好奇,34.7%因情感寄托,46.9%因生活环境影响。多因素分析结果显示,首次同性肛交年龄、首个同性性伴关系、进入MSM前交过女朋友、打算与异性结婚对象、艾滋病防治信息主要来源互联网、近6个月性伴健康是YMSM同性性行为成因的独立关联因素。结论 YMSM自认先天形成为主,其成因与社会家庭环境、早期性经历及自我健康有关。应注重青少年身心发展的良性环境营造和早期性教育。     

大学生男男性行为人群首次同性性行为与相关行为调查

目的:探索大学生男男性行为人群首次同性性行为与相关行为状况。方法:采用横断面调查方法。通过同伴推动抽样方法(RDS)和咨询检测等方式招募方便样本,一对一自填式问卷调查,收集人口学特征、首次性行为状况及安全套使用信息。结果:成功招募了127名大学生男男性行为者(MSM),88.2%的调查对象首次性行为对象是男性,首次同性性行为发生的年龄中位数为19岁;当第一个男性性伴是校外人员时,首次同性性行为被引诱或被胁迫的比例占到28.8%;首次性行为的性伴是男性其自认为性取向是同性恋的比例更高(χ~2=13.49,P=0.00);首次同性性行为时安全套使用率为70.1%,首次同性性行为使用安全套的调查对象最近一次肛交安全套使用比例更高(χ~2=7.72,P=0.05)。结论:首次同性性行为对青年学生的影响较大,应当关注学生首次性行为教育。     

绵阳市年轻男男性行为者出柜和自我身份认同现状及相关因素的分析

目的了解年轻男男性行为者(YMSM)出柜和自我身份认同(简称身份认同)现状,分析身份认同与相关因素的关系。方法本研究于2015年至2017年选取四川省绵阳市年龄范围15周岁～24周岁的362名男男性行为者作为调查对象。用滚雪球抽样法对这362名男性进行出柜、身份认同、行为、心理等调查和血清学检测。身份认同与相关因素关系单因素分析采用χ~2检验,多因素分析采用非条件Logistic回归。结果共回收有效问卷362份,调查对象出柜占19.3%(67/348),MSM身份消极认同占14.6%(53/362)、积极认同占85.4%(309/362)。消极认同、积极认者HIV、梅毒阳性率差异均无统计学意义(均P0.05)。多因素分析结果:月收入2000元(OR=3.403)、性伴相处不能坚持自我(OR=29.841)、首次同性性行为年龄20岁(OR=6.165)、曾有自杀念头(OR=3.883)、近1年做过HIV检测(OR=21.516)、近6个月有群交(OR=23.319)身份消极认同的可能性较大,近6个月做1肛交有保护性(OR=0.268)者较小。结论 YMSM出柜少,身份认同较好。身份认同与多种因素相关,消极认同增大了艾滋病感染风险,应针对性强化行为干预。     

江苏苏南MSM集中活动的娱乐场所人群状况调查

目的:了解江苏苏南地区MSM集中活动娱乐场所现场人员状况。方法:在集中时间段利用周末对现场人员开展现场人员生活环境、性行为、性病艾滋病知识等的问卷调查。结果:共有553人同意并参加了问卷调查,平均年龄28.78±9.24岁,绝大多数为未婚者并以同性性行为为主。他们的首次性行为发生的平均年龄为19.88±3.91岁,首次发生同性性行为的平均年龄21.58±4.78岁。近3个月有异性性伴者的平均异性伴数1.06±1.06个,有同性性伴者的平均同性性伴数2.51±2.30个。近3个月中肛交行为多于口交行为和手淫行为。其中17.2%的人不会正确使用安全套。性病艾滋病知识未达到90%正确的占31.3%。讨论:MSM聚集的娱乐场所是开展健康干预的重要场所,安全套推广应该更注重正确使用的细节宣传。     

2011-2015年广东省江门市男男性行为人群HIV和梅毒感染状况及影响因素分析

目的:了解江门市男男性行为人群(MSM)HIV和梅毒感染状况及其影响因素,为控制艾滋病性病的蔓延提供科学依据。方法:利用2011-2015年国家级MSM监测哨点的数据资料进行分析。结果:调查的1 916名调查对象中,艾滋病相关知识总体知晓率为90.19%;HIV抗体阳性率为6.73%,梅毒阳性率为4.07%。最近6个月与同性发生肛交性行为时每次都使用安全套的比例为51.93%。多因素Logistic回归分析结果显示,与异性婚姻状况为在婚/同居(OR=1.408,95%CI 1.153~1.720)、最近6个月与同性发生商业性行为(OR=2.458,95%CI 1.266~3.787)、感染梅毒(OR=5.804,95%CI3.196~10.540)是HIV感染的危险因素;吸毒(OR=1.164,95%CI 1.037~3.722)、最近6个月与同性发生肛交性行为(OR=10.753,95%CI 7.958~12.685)是梅毒感染的危险因素,而最近一年非梅毒STD史是梅毒感染的保护性因素(OR=0.239,95%CI 0.090~0.629)。结论:江门市MSM人群HIV和梅毒感染率较高,且梅毒、已婚/同居与同性发生商业性行为可增加HIV感染的风险;吸毒、与同性发生肛交性行为可增加梅毒感染的风险。     

男男性行为性病患者性行为特征分析

目的: 分析近一年曾患性传播感染(STI)的男男性行为者(men who have sex with men, MSM)性行为特征及感染STI的影响因素.方法: 对近一年曾患STI者的性行为及STI相关因素进行分析,并与未患STI者进行比较.结果: 近一年曾患STI的MSM同性性伴数、与同性性伴间的高危行为、网络寻找性伴并与网友发生性行为等方面均高于对照组.多因素分析,从事男男性工作和性交时出血与近一年患STI关系密切.结论: 应继续加强对MSM人群进行安全性行为健康教育,以降低STI和HIV感染风险.     

南宁市男男性行为者HIV感染确诊前后性行为变化及其影响因素分析

目的了解南宁市男男性行为人群(MSM)艾滋病病毒(HIV)感染者/患者确诊前后与固定同性性伴发生性行为的变化特征及其影响因素。方法 2016年5月-12月间匿名调查的124例HIV阳性MSM病例作为研究对象,对其调查结果进行分析。结果 124例研究对象平均年龄(28.40±9.90)岁,以未婚(72.58%)、汉族(61.29%)、大专及以上学历(50.81%)为主,78.23%通过互联网寻找同性伴侣;确诊前与固定同性性伴的安全套坚持使用率仅为17.31%,而确诊后与固定同性性伴的无保护性行为均减少(P0.001),且固定同性性伴数减少(P0.001)。固定同性性伴为阳性的比例分别从确诊前的24.04%上升到50.85%。多因素Logistic回归分析显示,确诊HIV阳性后发生无保护性行为的危险因素有:确诊前与固定同性性伴是否发生无保护性行为(OR=2.906,95%CI:1.675～5.962,P=0.017)、确诊后固定同性性伴数(OR=1.511,95%CI:1.232～1.978,P=0.014)。结论 MSM人群HIV感染者在确诊后无保护性肛交和多性伴性行为明显减少,但部分仍保持高危性行为,应进一步开展扩大检测和抗病毒治疗等干预措施,尽早发现感染者,控制HIV在该人群中的流行及"二代传播"。     

昆明市不同性角色MSM的性行为特征分析

目的了解昆明市不同性角色男男性行为者(MSM)的行为特点,为制定个体化的干预措施提供科学依据。方法在知情同意前提下,由经过培训的调查员对MSM开展面对面问卷调查。采用SPSS 17.0软件包进行统计分析,用x~2检验对不同组间各种率进行分析比较。结果根据问卷调查自我报告的性角色不同将MSM分为不同亚人群。根据MSM人群在肛交过程中的性角色不同,将其分为三类:1号是指在与同性发生肛交时,仅作为主动插入方;0号是指在与同性发生肛交时,仅作为被动插入的一方;0.5号是指在与同性发生性行为时,既可以作为主动插入的一方,也可以作为被动插入的一方。在224名MSM中,1号93人,占41.5%(93/224);0号64人,占28.6%(64/224);0.5号67人,占29.9%(67/224)。0号MSM具有以下性行为特征:发生首次性行为的年龄更小,首次性行为的性伴以男性更多,最近6个月内与男性发生肛交的比例最大,较少与女性发生性行为,女性性伴数量相对更少。1号具有以下性行为特征:和女性结婚比例更高,首次性行为性伴以女性为多。0.5号有以下性行为特征:在婚者最多,首次性行为性伴以女性为多,拥有更多女性性伴,与女性发生性行为的比例最高。结论不同性角色的MSM亚人群行为各具特点,应针对具体的行为特点制定个体化干预策略。     

未婚人工流产女性非意愿首次性行为的相关因素及生殖健康结局研究

目的：了解非意愿首次性行为与有关因素的关联情况,探索其与人工流产、避孕、生殖道感染等生殖健康事件、健康结局的关联。方法：在上海3家不同等级、常规提供人工流产服务的医院,纳入年龄小于25岁、来院进行人工流产的未婚女性开展匿名问卷调查。结果：调查对象发生首次性行为的平均年龄为19.6岁,8.4%的调查对象首次性行为是与非固定性伴发生的,15.3%的调查对象首次性行为是非意愿的;首次性行为年龄小、首次性行为与非固定性伴发生的对象较容易发生非意愿首次性行为;发生非意愿首次性行为的对象更早发生人工流产,更可能与非固定性伴发生性行为造成本次意外妊娠,在以后的性经历中更可能有多性伴,更可能曾因为性伴的原因而不使用避孕措施,更可能出现生殖道感染症状。结论：非意愿首次性行为与发生首次性行为的年龄、性伴类型相关,发生非意愿首次性行为会影响青少年今后的性行为模式、危害青少年的性与生殖健康。     

广州市男男性行为人群STD/HIV相关高危行为特征及就诊延误影响因素调查分析

目的:了解广州市男男性行为(MSM)人群STD/HIV相关高危行为特征和就诊延误影响因素,为制定有针对性的防控措施提供依据。方法:2014年10月至2015年9月期间,对参加STD/HIV自愿咨询检测且已经出现疑似STD/HIV感染相关症状、近2年内发生过同性性行为的MSM进行面对面问卷调查,采集静脉血检测HIV和梅毒。结果:共调查313名MSM,38.02%近2年内与异性发生过性行为,40.89%拥有固定的同性性伴,肛交性行为中每次都使用安全套的比例为47.04%。本次病程中80.51%发生就诊延误,首次就诊间隔时间平均为30天,影响就诊延误的因素主要包括职业、对同性恋的态度、近2年是否发生异性性行为、是否曾患其它非梅毒性病、就诊频次、是否暂停性生活。血清学监测结果 HIV感染率为20.77%,现症梅毒感染率为6.39%,同时感染HIV和梅毒的比例为4.79%,就诊延误发生者的HIV感染率和梅毒感染率均高于未发生就诊延误者,差异有统计学意义(P值均0.05)。结论:广州市MSM人群HIV感染率高,高危行为普遍存在,就诊延误发生率高,防控形势严峻,应加大宣传教育、提高医疗服务可及性和服务质量以减少就诊延误的发生。     

Commercial sex venues: a closer look at their impact on the syphilis and HIV epidemics among men who have sex with men

OBJECTIVE: To provide insight into the role of commercial sex venues in the spread of syphilis and HIV among men who have sex with men (MSM). Study: A cross sectional study of 1351 MSM who were diagnosed with early syphilis who did and did not encounter sexual partners at commercial sex venues. RESULTS: Overall, 26% MSM diagnosed with syphilis had sexual encounters at commercial sex venues. Of these, 74% were HIV positive, 94% reported anonymous sex, and 66% did not use a condom. Compared to those who did not have a sexual encounter at these venues, they were twice as likely to be HIV positive (OR = 1.91, 95% CI 1.36 to 2.68), six times more likely to have anonymous sex (OR = 6.18, 95% CI 3.37 to 11.32), twice as likely not to use condom (OR = 2.02, 95% CI 1.71 to 2.38), and twice as likely to use non-injecting drugs (OR = 1.65, 95% CI 1.21 to 2.37). CONCLUSIONS: MSM diagnosed with syphilis who frequent commercial sex venues are engaging in high risk behaviours for syphilis and HIV transmission and acquisition. Thus commercial sex venues are one of the focal points of syphilis and HIV transmission and acquisition.     

Homosexual men's HIV related sexual risk behaviour in Scotland

OBJECTIVE: To date, the epidemic of HIV infection in Scotland has been primarily associated with injecting drug use. However, the epidemiology of HIV in Scotland changed in the late 1980s, with homosexual men becoming the largest group at risk of HIV infection and AIDS. Our aim was to describe homosexual men's sexual risk behaviours for HIV infection in a sample of men in Scotland's two largest cities. DESIGN/SETTING: Trained sessional research staff administered a short self completed questionnaire, to homosexual men present in all of Glasgow's and Edinburgh's "gay bars," during a 1 month period. SUBJECTS: A total of 2276 homosexual men participated, with a response rate of 78.5%. Of these, 1245 were contacted in Glasgow and 1031 in Edinburgh. MAIN OUTCOME MEASURES: Sociodemographic data, recent (past year) sexual behaviour, information on last occasion of anal intercourse with and without condoms, and sexual health service use. RESULTS: Anal intercourse is a common behaviour; 75% of men have had anal intercourse in the past year. A third of our sample report anal intercourse with one partner in the past year, but 42% have had anal intercourse with multiple partners. Over two thirds of the total population have not had any unprotected anal intercourse (UAI) in the past year and a quarter of the sample have had UAI with one partner only. 8% report UAI with two or more partners. More men in Edinburgh (17% v 10%) reported unprotected sex with casual partners only, but more men in Glasgow (29% v 20%) reported UAI with both casual and regular partners (chi 2 = 12.183 p < 0.02). Multiple logistical regression found that odds of UAI are 30% lower for men with degree level education and 40% lower for men who claim to know their own HIV status, whereas they are 40% higher for those who have been tested for HIV and 48% higher for infrequent visitors to the "gay scene". Men who have had an STI in the past year are 2.4 times more likely to report UAI than those who have not. Men with a regular partner were significantly more likely to report UAI, as were those who had known their partner for longer, and who claimed to know their partner's antibody status. CONCLUSION: On the basis of current sexual risk taking, the epidemic of HIV among homosexual men in Scotland will continue in future years. The data reported here will prove useful both for surveillance of sexual risk taking, and the effectiveness of Scotland-wide and UK-wide HIV prevention efforts among homosexual men.     

Prevalence of bisexual behaviors among men who have sex with men (MSM) in China and associations between condom use in MSM and heterosexual behaviors

OBJECTIVES: This study investigated the prevalence of bisexual behaviors and marital status among Chinese men who have sex with men (MSM) and the associations between MSM's condom use and their heterosexual behaviors. METHODOLOGY: Eight hundred ninety-six adult males in Yunnan Province, China, who reported to ever have engaged in MSM behaviors were interviewed. Data were acquired through the China-UK HIV/AIDS Prevention and Care Project from 2003 to 2006. RESULTS: Of all respondents, one-third had ever been married, 59% had ever engaged in bisexual behaviors, and 31% had done so in the past 6 months. High prevalence of inconsistent condom use was reported in heterosexual behaviors (71.9%), as well as with those who had engaged in MSM sexual behaviors in the past 6 months (30.8% with commercial sex workers and 54.7% with noncommercial sex partners) in the past 6 months. Those who did not use condoms with MSM partners were also more likely than others to not use condoms with their female sex partners (FSP). Those who had voluntary counseling and testing services were more likely than others to have used a condom in the last episode of sex with their FSP (multivariate odds ratio = 1.66). CONCLUSIONS: The clustering of unprotected sexual behaviors with male and FSP among bisexual MSM is revealed. The bridging effects of the risk for human immunodeficiency virus transmission from the MSM population to the female population are evident.     

HIV, sexually transmitted infections, and risk behaviours in male commercial sex workers in Sydney

OBJECTIVES: To assess prevalence of HIV and sexually transmitted infections (STIs), risk behaviours, and demographics in male commercial sex workers (CSWs)/prostitutes in Sydney. METHODS: Retrospective, cross sectional study with two comparison groups. Demographic, behavioural, and morbidity data were analysed from standardised medical records of patients attending a public STI and HIV service in Sydney between January 1991 and March 1998. Two comparison groups were used: female CSWs and non-CSW working homosexual men who attended over the same time. RESULTS: 94 male CSWs, 1671 female CSWs, and 3541 non-CSW working homosexual men were included. The prevalence of HIV in male CSWs tested (6.5%) was significantly greater than in female CSWs (0.4%, p = 0.0001), but less than in non-CSW homosexual men (23.9%, p < 0.0001). Genital warts occurred significantly more frequently in male CSWs than in comparison groups. Prevalence of other STIs was similar in all groups. Male CSWs saw significantly fewer clients per week than female CSWs and male and female CSWs used condoms with almost all clients. Male CSWs reported significantly more non-work sexual partners than female CSWs and non-CSW homosexual men and were significantly more likely to have unprotected penetrative sex with their non-work partners than non-CSW homosexual men. Injecting drug use was significantly more frequent in male CSWs than in both comparison groups. CONCLUSIONS: Although male CSWs use condoms with clients, they are more likely to practise unsafe sex with non-work partners (especially women) and inject drugs than female CSWs and non-CSW homosexual men. Some men with HIV are working within the commercial sex industry. Targeted health education to encourage safer drug use and safer sex outside work is needed.     

Association between 'safer sex fatigue' and rectal gonorrhea is mediated by unsafe sex with casual partners among HIV-positive homosexual men

OBJECTIVE: The objective of this study was to investigate whether and what sexual risk behavior is a mediator of associations between rectal gonorrhea (RG) and highly active antiretroviral therapy-related beliefs, safer sex fatigue, or sexual sensation-seeking among homosexual men. STUDY DESIGN: This study consisted of a cross-sectional survey between March 2002 and December 2003 among homosexual visitors of the Amsterdam sexually transmitted disease clinic. METHODS: In total, 1568 men answered a written questionnaire. Associations were determined using logistic regression corrected for repeated measurements. RESULTS: The RG infection rate was high among homosexual men who were HIV-positive (16%) compared with those with negative or unknown HIV status. Mediation could be confirmed among HIV-positive men only. Those who experienced higher levels of safer sex fatigue were more likely to be positive for RG. This association was mediated by unprotected anal intercourse (UAI) with casual partners. CONCLUSION: Addressing safer sex fatigue might help prevent UAI with casual partners and possibly also RG among HIV-positive homosexual men.     

The Gay Men's Task Force: the impact of peer education on the sexual health behaviour of homosexual men in Glasgow.

OBJECTIVE: To assess the impact of a peer education intervention, based in the "gay" bars of Glasgow, which sought to reduce sexual risk behaviours for HIV infection and increase use of a dedicated homosexual men's sexual health service, and in particular increase the uptake of hepatitis B vaccination. DESIGN: Self completed questionnaires administered to men who have sex with men (MSM) in Glasgow's gay bars. SUBJECTS: 1442 men completed questionnaires in January 1999, 7 months after the end of the 9 month sexual health intervention. MAIN OUTCOME MEASURES: Self reported contact with the peer education intervention, reported behaviour change, and reported sexual health service use. RESULTS: The Gay Men's Task Force (GMTF) symbol was recognised by 42% of the men surveyed. Among men who reported speaking with peer educators 49% reported thinking about their sexual behaviour and 26% reported changing their sexual behaviour. Logistic regressions demonstrated higher levels of HIV testing, hepatitis B vaccination, and use of sexual health services among men who reported contact with the intervention. These men were more likely to have used the homosexual specific sexual health service. Peer education dose effects were suggested, with the likelihood of HIV testing, hepatitis B vaccination, and use of sexual health services being greater among men who reported talking to peer educators more than once. CONCLUSION: The intervention had a direct impact on Glasgow's homosexual men and reached men of all ages and social classes. Higher levels of sexual health service use and uptake of specific services among men who had contact with the intervention are suggestive of an intervention effect. Peer education, as a form of health outreach, appears to be an effective intervention tool in terms of the uptake of sexual health services, but is less effective in achieving actual sexual behaviour change among homosexual men.     

Surveillance of sexual behaviour among homosexual men in a central London health authority.

OBJECTIVE: To establish a surveillance mechanism of high risk sexual behaviour among homosexual and bisexual men living, socialising and using services in a central London health authority. DESIGN: Baseline survey for a system of repeatable behavioural surveillance using a self-completed questionnaire delivered by healthcare providers. SETTING: Genitourinary medicine clinics, gay bars, clubs, community groups and a cruising ground in the defined geographical area of a central London health authority. PARTICIPANTS: Five hundred and fifty three homosexual and bisexual men. MAIN OUTCOME MEASURES: Self-reported behaviours including unprotected anal intercourse (UAI), HIV status of unprotected anal intercourse partners, uptake of HIV testing and use of condoms at first time of anal intercourse. RESULTS: Five hundred and sixty questionnaires were returned (response rate 76%) from 553 men. A third (35%) of men surveyed had had UAI in the previous year. Nearly a fifth (19%) of the sample had had UAI with one or more partners of a discordant or unknown HIV status. A total of 343 (63%) men had had an HIV test. The proportion of men using condoms on the occasion of first anal intercourse has risen from 6% before 1980 to 88% after 1993. CONCLUSIONS: We have demonstrated that a surveillance programme to monitor high risk sexual behaviour among homosexual men can be easily established. The results can be employed to assess progress towards risk reduction targets and also inform future policy development. Our baseline data demonstrate that a large proportion of homosexual men are continuing to engage in high risk sexual behaviour, although there is some evidence of improvement in condom use at first anal intercourse over time. There is a need for continuing health promotion with evaluation among homosexual men.     

浴池型男男性行为人群HIV感染现状及预防

通过查询文献,分析浴池型男男性行为人群HIV感染状况及影响因素。浴池MSM人群有其特殊性,浴池型MSM更有可能发生不安全性行为;在同性恋浴池内感染性病、艾滋病的风险随年龄的增大而增大;在浴池活动的MSM,更容易暴露于感染的危险中;作为桥梁人群,不但增大了其他MSM人群HIV感染风险,同时也增加了HIV向普通人群蔓延的危险;监测和干预难度较大,对阳性者的管理难以达到目的。     

深圳男男性接触者多性伴与社交软件使用习惯现况及相关性分析

目的：调查深圳地区男男性接触者(MSM)近6个月同性多性伴和社交软件使用现况，探索两者关系。方法：2016年8月至2017年6月，运用滚雪球法和同伴推动抽样法在深圳市招募315名MSM进行问卷调查，收集该人群社会人口学、近6个月同性性伴数、同志社交软件使用习惯等信息。应用χ2检验和有序Logistic回归分析性伴数量和同志社交软件使用习惯的关系。结果：共291名MSM纳入调查，其近6个月同性性伴数中位数为2（四分位数间距：1～5）人，其中“0～1人性伴组”占28.2%，“2～4人性伴组”占46.7%，“≥5人性伴组”占25.1%。有序Logistic回归分析结果显示，多种方式寻找性伴（aOR=1.14,95% CI：1.05～1.86），使用同志社交软件获得一夜情（aOR=2.00,95% CI：1.46～2.73）或寻找性伴的频率2次/每月及以上（aOR=2.70,95% CI：1.77～4.12）的MSM性伴数量更多。结论：MSM近6个月多性伴较普遍，与同志社交软件使用习惯相关。     

Individual characteristics are less important than event characteristics in predicting protected and unprotected anal intercourse among homosexual and bisexual men in Melbourne, Australia

OBJECTIVE: To describe individual, social network and encounter specific factors associated with protected anal intercourse (PAI) and unprotected anal intercourse (UAI). METHODS: This was a cross sectional survey conducted between April and November 2002. A total of 733 sexual encounters were reported by 202 men recruited from the gay community in Melbourne, Australia. Predictors of self reported PAI and UAI were examined. RESULTS: Of the 733 sexual events most (56.3%) did not involve anal intercourse, and more involved PAI than UAI (30.6% versus 13.1%). PAI was more likely than no anal intercourse (NAI) if the participant's social network was mostly homosexual, the partner was an occasional or casual partner, or was HIV positive. PAI was less likely if sex took place at a "beat" but more likely if it took place at a sauna. PAI was more likely if the partner was affected by drugs or alcohol. UAI was more likely than NAI if the participant had injected drugs in the year before interview. It was less likely if the partner was occasional or casual or was HIV positive but more likely if the partner's HIV status was unknown. UAI was much more likely than NAI if the encounter took place at a "sex on premises" venue. CONCLUSIONS: In this analysis it is the characteristics of the sexual encounter that predict whether PAI or UAI rather than NAI takes place.