HIV transmission risk behavior among men and women living with HIV in 4 cities in the United States

Determining rates of HIV transmission risk behavior among HIV-positive individuals is a public health priority, especially as infected persons live longer because of improved medical treatments. Few studies have assessed the potential for transmission to the partners of HIV-positive persons who engage in high-risk activities. A total of 3723 HIV-infected persons (1918 men who have sex with men [MSM], 978 women, and 827 heterosexual men) were interviewed in clinics and community-based agencies in Los Angeles, Milwaukee, New York City, and San Francisco from June 2000 to January 2002 regarding sexual and drug use behaviors that confer risk for transmitting HIV. Less than one quarter of women and heterosexual men had 2 or more sexual partners, whereas 59% of MSM reported having multiple partners. Most unprotected vaginal and anal sexual activity took place in the context of relationships with other HIV-positive individuals. Approximately 19% of women, 15.6% of MSM, and 13.1% of heterosexual men engaged in unprotected vaginal or anal intercourse with partners who were HIV-negative or whose serostatus was unknown. The majority of sexually active participants disclosed their serostatus to all partners with whom they engaged in unprotected intercourse. An estimated 30.4 new infections (79.7% as a result of sexual interactions with MSM) would be expected among the sex partners of study participants during the 3-month reporting period. Eighteen percent of 304 participants who injected drugs in the past 3 months reported lending their used injection equipment to others. In addition to the more traditional approaches of HIV test counseling and of focusing on persons not infected, intensive prevention programs for persons with HIV infection are needed to stem the future spread of the virus.     

Unprotected anal intercourse between potentially HIV-serodiscordant men who have sex with men,San Francisco

BACKGROUND: Increasing trends in high-risk sexual behavior are noted among men who have sex with men (MSM) worldwide. Less information is available on unprotected sex between persons of different HIV serostatus. METHODS: From 1999 through 2001, volunteers of a community-based organization conducted interviews of 10,579 MSM at gay-oriented venues in San Francisco and in neighborhoods with high-volume MSM pedestrian traffic. The questionnaire recorded demographic and risk behavior information, including self-reported and partners' HIV serostatus. RESULTS: Potentially serodiscordant unprotected anal intercourse (UAI) with at least 2 anal sex partners was reported by 12.7% and increased from 11.0% in 1999 to 16.2% in 2001. Stratifying by self-reported HIV serostatus, 20.8% of HIV-positive respondents, 12.1% of HIV-negative respondents, and 13.4% of MSM who did not know or report their own HIV serostatus had potentially serodiscordant UAI. Older MSM of white race were more likely to report potentially serodiscordant UAI among HIV-positive respondents, whereas younger MSM of white race were more likely to report potentially serodiscordant UAI among HIV-negative respondents. Among those with unknown HIV serostatus, MSM of color were more likely to engage in potentially serodiscordant UAI. CONCLUSION: Recent increases in UAI among MSM in San Francisco are not only the result of increases in UAI between persons of the same HIV serostatus. Prevention messages must address disclosure of HIV serostatus to sexual partners specifically tailored to groups according to age, community, and HIV serostatus.     

Longitudinal patterns of sexual behavior and condom use in a cohort of HIV-negative gay and bisexual men in Vancouver, British Columbia, Canada, 1995-2000

OBJECTIVE: To characterize longitudinal patterns of sexual behavior in a cohort of young gay and bisexual men and determine their reasons for not using condoms. METHODS: Prospective data from a cohort of young gay and bisexual men aged 18 to 30 years were studied. Study participants had completed a baseline questionnaire and HIV test between May 1995 and April 1996 and four annual follow-up questionnaires. RESULTS: A total of 130 HIV-negative Vanguard participants met the eligibility criteria for this analysis. The median age at baseline was 26 years (range, 24-28). Most were white (79%), had completed high school (85%), were currently employed (82%), lived in stable housing (95%), and reported annual incomes of > or =$10,000 (82%). (All dollar amounts are given in Canadian dollars.) Consistently over the 5-year study period, > 70% of study subjects reported having > or =1 regular male sexual partners in the previous year. During each of the five successive 1-year periods, between 34% and 40% of respondents reported having had unprotected receptive anal intercourse with regular partners. Slightly fewer individuals (between 29%-39%) reported having had unprotected insertive anal intercourse with regular partners. Between 13% and 25% of participants reported having had insertive unprotected anal intercourse with casual sexual partners; and between 9% and 18% reported having had unprotected receptive anal intercourse with casual sexual partners. Reasons for engaging in unprotected anal intercourse varied depending on type of sexual partnership. CONCLUSION: High-risk sexual behaviors remained fairly consistent over a 5-year period in this study. This suggests that it is critically important to understand the motivations for unprotected sex when designing and implementing programs aimed at reducing HIV risk among young gay and bisexual men.     

HIV-positive men's sexual practices in the context of self-disclosure of HIV status

OBJECTIVE: To examine whether disclosure of HIV-positive status to sex partners at risk for HIV infection is associated with safer sex practices and to examine the prevalence and correlates of specific disclosure/sexual behavior patterns. METHODS: Cross-sectional assessment of 206 HIV-positive men (41% homosexual, 35% bisexual, 24% heterosexual) sampled randomly at an outpatient HIV clinic in Los Angeles, who reported that their most recent sex partner was HIV-negative or of unknown serostatus. Unsafe sex was defined as unprotected anal or vaginal intercourse with that partner. RESULTS: Twenty-five percent of the men engaged in unsafe sex, and 48% of the total sample withheld disclosure from the partner. The prevalence of safer sex was not significantly higher among disclosers than among nondisclosers (unadjusted odds ratio = 1.29; 95% confidence interval: 0.69-2.45), and disclosure was not significantly associated with safer sex in any of 25 demographic or partner subgroups examined in the study. In the full sample, 40% of the men disclosed and engaged in safer sex (informed protection), 35% withheld disclosure and engaged in safer sex (uninformed protection), 12% informed their partner and engaged in unsafe sexual behavior (informed exposure), and 13% withheld disclosure and engaged in unsafe sex (uninformed exposure). Risky behavior patterns were associated with using alcohol/drugs before sex, having an HIV-unknown partner, being less emotionally involved with one's partner, and testing seropositive in the previous 3 years. CONCLUSIONS: Interventions for seropositive men that focus primarily on increasing disclosure of serostatus to sex partners may not reduce the prevalence of unsafe sex. Interventions are needed to address the social and psychologic processes that give rise to risky behavior patterns in HIV-infected men. Improved substance abuse counseling also may be needed.     

Sexual risk behavior among HIV-positive men who have sex with men: a literature review

OBJECTIVE: To review research on sexual risk behavior among HIV-positive men who have sex with men (MSM) after the year 2000. METHOD: The review included 53 published studies that reported on unprotected anal intercourse (UAI) in cross-sectional and longitudinal surveys of HIV-positive MSM and MSM of mixed HIV status. RESULTS: The findings indicate high levels of UAI among HIV-positive MSM, particularly with HIV-negative or HIV status unknown partners. In studies of MSM of mixed HIV status, we found that the rate of UAI among HIV-positive MSM was much higher than that of HIV-negative MSM. Furthermore, the prevalence of UAI among HIV-positive MSM has increased in recent years. CONCLUSION: Although studies indicate that HIV-positive MSM have adopted risk reduction strategies, roughly two in five HIV-positive MSM continue to engage in UAI, which represents a risk for continued HIV and STI (sexually transmitted infection) transmission. PRACTICE IMPLICATIONS: Prevention efforts targeting HIV-positive MSM to assist them in adopting and maintaining safer sexual behaviors need to be intensified.     

Discussion of HIV status by serostatus and partnership sexual risk among internet-using MSM in the United States

Men who have sex with men (MSM), particularly black MSM, are disproportionally infected with HIV. Little is known about how discussion of HIV status between partners varies among MSM by race/ethnicity and by HIV transmission risk. Among a national survey of 2031 MSM reporting 5410 partnerships, black MSM, especially black HIV-positive MSM, serodiscussed with unprotected anal intercourse partners less than did white MSM. Although non-black HIV-positive, non-black HIV-negative MSM, and black HIV-negative MSM were more likely to report serodiscussion with unprotected anal intercourse partners, black HIV-positive MSM were not. Differential serodiscussion may play a role in explaining the racial/ethnic disparity in HIV incidence.     

Drug use and sexual risk behavior among gay and bisexual men who attend circuit parties: a venue-based comparison.

CONTEXT: HIV risk behavior among urban gay/bisexual men has recently increased. High-risk sexual activity and drug use may be particularly high during circuit party (CP) weekends, during which gay/bisexual men congregate for social activities and dancing. OBJECTIVES: To compare prevalence of risk behaviors during CP weekends with those during non-CP weekends. DESIGN: Cross-sectional study. PARTICIPANTS: 295 gay/bisexual men from the San Francisco Bay Area. MAIN OUTCOME MEASURES: Drug use and sexual risk behavior during a San Francisco CP weekend, a CP weekend held in another geographic area (distant weekends), and two non-CP weekends. RESULTS: During their most recent distant CP weekend, 80% of participants used methylenedioxymethamphetamine (ecstasy), 66% ketamine, 43% crystal methamphetamines, 29% gamma-hydroxybutyrate or gamma-butyrolactone (GHB/GBL), 14% sildenafil (Viagra), and 12% amyl nitrites (poppers); 53% used four or more drugs. Drug use prevalence was greater during CP than non-CP weekends ( p <.001). Unprotected anal sex with partners of unknown or opposite HIV serostatus was most prevalent during distant CP weekends, reported by 21% of HIV-positive and 9% of HIV-negative participants. In multivariate analysis, predictors of unprotected anal sex with opposite or unknown HIV serostatus partners included being HIV-positive (odds ratio [OR], 3.2; 95% confidence interval [CI], 1.4-7.5), and weekend use of crystal methamphetamines (OR 2.4; 95% CI, 1.1-4.9), sildenafil (OR, 3.8; 95% CI, 2.0-7.3), and amyl nitrites (OR, 2.2; 95% CI, 1.3-4.0). CONCLUSIONS: Prevalence of high-risk activity during these weekends suggests significant potential for HIV transmission in this population. Public health programs in communities hosting CPs should aim to reduce rates of drug use and sexual risk behavior among CP participants, especially HIV-positive men.     

Partner-specific sexual behavioral differences between phase 3 HIV vaccine efficacy trial participants and controls: Project VISION

OBJECTIVE: To assess and compare sexual behaviors using partner-specific data between HIV-negative men who have sex with men (MSM) recruited for an HIV vaccine efficacy trial and a control group. METHODS: HIV-negative MSM from an HIV vaccine trial (n = 525) and controls (n = 732) were recruited by similar strategies and interviewed about behaviors with the 3 most recent partners in the past 6 months, obtained by audio computer-assisted self-interview (A-CASI). RESULTS: Vaccine trial participants were more likely than controls to report an HIV-positive partner (24.7% and 14.1%, respectively) or an HIV-positive primary partner (16.1% and 6.8%, respectively) and were less likely to report occasional or single-time partners of unknown HIV status (51.6% and 63.2%, respectively; P < 0.05 for each comparison). Vaccine trial participants more often reported receptive unprotected anal intercourse (UAI) during their last sexual encounter with an HIV-positive partner (adjusted odds ratio [OR] = 2.7, 95% confidence interval [CI]: 1.0 to 7.9). Most believed their HIV-positive partners were receiving antiretroviral treatment (ART), however, and after adjustment for perceived ART use, the association between vaccine study participation and receptive UAI with an HIV-positive partner was not significant. CONCLUSIONS: High-risk sexual behavior was reported by many VAX004 participants and controls. Differences between vaccine trial and control participants in the highest risk per contact behavior, receptive UAI with HIV-positive partners, was partly accounted for by perceived ART use. Partner level data are useful in refining risk assessment, which is important in the evaluation of HIV vaccine and other prevention trials.     

Risk factors associated with HIV infection among young gay and bisexual men in Canada

OBJECTIVE: To assess risk factors associated with HIV prevalence and incidence among gay and bisexual men in two prospective Canadian cohorts. METHODS: The Vanguard Project and the Omega Cohort are prospective cohort studies of gay and bisexual men ongoing in Vancouver and Montreal, respectively. For this analysis, baseline sociodemographic characteristics, sexual behavior, and substance use data from these two cohorts were combined. Assessment of risk factors for HIV seroprevalence and seroconversion were carried out using univariate and multivariate analysis. RESULTS: This analysis was based on 1373 gay and bisexual men aged 16 to 30 years. Men who were HIV-seropositive at baseline (n = 48) were more likely to report living in unstable housing, to have had less than a high school education, and to have been unemployed than those who were HIV-negative (n = 1325). HIV-positive men were also more likely to report having engaged in sexual risk behavior, including having had consensual sex at a younger age, having had at least 6 partners during the previous year, ever having been involved in the sex trade, and having engaged in unprotected receptive anal intercourse. With respect to substance use, HIV-positive men were more likely to report the use of crack, cocaine, heroin, and marijuana and to use injection drugs. Similarly, men who seroconverted during the course of the studies (n = 26) were more likely to report having less than a high school education and having lived in unstable housing at baseline. Compared with HIV-negative men, men who seroconverted were more likely to report ever having been involved in the sex trade and engaging in unprotected receptive anal intercourse. Reports of cocaine use and injection drug use were also significantly higher for men who seroconverted compared with HIV-negative men. CONCLUSIONS: Our data indicate that HIV-positive gay and bisexual men are more likely to be living in unstable conditions and to report more risky sexual and substance use behaviors than HIV-negative men.     

Changing sexual behavior among gay male repeat testers for HIV: a randomized,controlled trial of a single-session intervention

CONTEXT: High-risk sexual behavior is increasingly prevalent among men who have sex with men (MSM) and among men with a history of repeat testing for HIV. OBJECTIVES: The study assessed whether one counseling intervention session focusing on self-justifications (thoughts, attitudes, or beliefs that allow the participant to engage in high-risk sexual behaviors) at most recent unprotected anal intercourse (UAI) is effective in reducing future high-risk behaviors among HIV-negative men. DESIGN, SETTING, AND PARTICIPANTS: A randomized, controlled, counseling intervention trial was conducted at an anonymous testing site in San Francisco, California, between May 1997 and January 2000. Participants were 248 MSM with a history of at least one previous negative HIV test result and self-reported UAI (receptive or insertive) in the previous 12 months with partners of unknown or discordant HIV status. Two intervention groups received standard HIV test counseling plus a cognitive-behavioral intervention, and two control groups received only standard HIV test counseling. Follow-up evaluation was at 6 and 12 months. MAIN OUTCOME MEASURE: Number of episodes of UAI with nonprimary partners (of unknown or discordant HIV status) in the 90 days preceding the interview was measured via self-report during face-to-face interview. RESULTS: A novel counseling intervention focusing on self-justifications significantly decreased the proportion of participants reporting UAI with nonprimary partners of unknown or discordant HIV status at 6 and 12 months (from 66% to 21% at 6 months and to 26% at 12 months, p =.002; p <.001) as compared with a control group when added to standard client-centered HIV counseling and testing. CONCLUSIONS: A specific, single-session counseling intervention focusing on a reevaluation of a person's self-justifications operant during a recent occasion of high-risk behavior may prove useful in decreasing individual risk behavior and thus limiting community-level HIV transmission.     

Childhood sexual abuse and sexual risk behavior among men and women attending a sexually transmitted disease clinic

Childhood sexual abuse (CSA) is associated with a wide range of negative outcomes. The authors investigated the relation between CSA and sexual risk behavior in 827 patients recruited from a sexually transmitted disease (STD) clinic. Overall, CSA was reported by 53% of women and 49% of men and was associated with greater sexual risk behavior, including more sexual partners, unprotected sex, and sex trading. Alcohol use for men and drug use for women mediated the relation between CSA and the number of sexual partners in the past 3 months; intimate partner violence mediated the relation between CSA and the number of episodes of unprotected sex in the past 3 months for women. These results document the prevalence of CSA among patients seeking care for an STD and can be used to tailor sexual risk reduction programs for individuals who were sexually abused.     

A longitudinal study of the association between treatment optimism and sexual risk behavior in young adult gay and bisexual men

To determine whether optimism about highly active antiretroviral therapy is associated with sexual risk behavior among young adult HIV-negative gay and bisexual men, and to test 2 alternative explanations for this association: that treatment optimism leads to increased sexual risk or that treatment optimism is the result of previous sexual risk. Data on sexual risk behavior, treatment optimism, and perceived susceptibility to HIV infection were obtained from a sample of 538 HIV-negative or untested gay and bisexual men (ages 18-30) who were not in monogamous relationships. Follow-up data were collected 18 months later. In the cross-sectional data, treatment optimism was associated with the 2-month cumulative incidence of unprotected anal intercourse (UAI) with nonprimary partners; however, this effect was observed only among men who felt highly susceptible to HIV infection. Longitudinal analyses revealed that treatment optimism did not predict subsequent UAI, but UAI did predict later treatment optimism. Treatment optimism is associated with sexual risk behavior among young adult gay and bisexual men. However, these data suggest that optimism may result from, rather than precede, sexual risk.     

A randomized clinical trial of a coping improvement group intervention for HIV-infected older adults

This research tested if a 12-session coping improvement group intervention (n = 104) reduced depressive symptoms in HIV-infected older adults compared to an interpersonal support group intervention (n = 105) and an individual therapy upon request (ITUR) control condition (n = 86). Participants were 295 HIV-infected men and women 50-plus years of age living in New York City, Cincinnati, OH, and Columbus, OH. Using A-CASI assessment methodology, participants provided data on their depressive symptoms using the Geriatric Depression Screening Scale (GDS) at pre-intervention, post-intervention, and 4- and 8-month follow-up. Whether conducted with all participants (N = 295) or only a subset of participants diagnosed with mild, moderate, or severe depressive symptoms (N = 171), mixed models analyses of repeated measures found that both coping improvement and interpersonal support group intervention participants reported fewer depressive symptoms than ITUR controls at post-intervention, 4-month follow-up, and 8-month follow-up. The effect sizes of the differences between the two active interventions and the control group were greater when outcome analyses were limited to those participants with mild, moderate, or severe depressive symptoms. At no assessment period did coping improvement and interpersonal support group intervention participants differ in depressive symptoms.     

Intimate partner violence perpetration against main female partners among HIV-positive male injection drug users

Intimate partner violence (IPV) against women is a serious public health and social problem and is associated with a host of adverse health outcomes and behaviors, HIV risk behaviors included, among women who are victimized. Historically, research has focused on correlates of IPV victimization among women; thus, there is less information on the role of men in perpetrating IPV, particularly among men at risk for transmitting HIV to their female partners. We assessed the self-reported prevalence and correlates of perpetration and threat of perpetration of physical and/or sexual IPV against a main female partner among 317 HIV-positive men who were current injection drug users (IDUs). More than 40% of men reported perpetrating physical (39%) and/or sexual (4%) violence against their main female partners in the past year. Multivariate analyses revealed that low education, homelessness, psychologic distress, and unprotected sex with main and nonmain HIV-negative female partners were positively associated with IPV perpetration against main female partners. These findings reveal that IPV perpetration is prevalent among HIV-positive male IDUs and associated with sexual HIV transmission risk behaviors. IPV assessment and treatment among HIV-positive men in HIV care is recommended as a way to prevent IPV perpetration and victimization and to reduce potential HIV transmission.     

Incidence of HIV infection in stable sexual partnerships: a retrospective cohort study of 1802 couples in Mwanza Region,Tanzania

OBJECTIVE: To describe the dynamics of HIV transmission in stable sexual partnerships in rural Tanzania. DESIGN: Retrospective cohort study nested within community-randomized trial to investigate the impact of a sexually transmitted disease treatment program. METHODS: A cohort of 1802 couples was followed up for 2 years, with the HIV status of each couple assessed at baseline and follow-up. RESULTS: At baseline, 96.7% of couples were concordant-negative, 0.9% were concordant-positive, 1.2% were discordant with the male partner being HIV-positive, and 1.2% were discordant with the female partner being HIV-positive. Individuals living with an HIV-positive partner were more likely to be HIV-positive at baseline (women: odds ratio [OR] = 75.7, 95% confidence interval [CI]: 33.4-172; men: OR = 62.4, CI: 28.5-137). Seroincidence rates in discordant couples were 10 per 100 person-years (py) and 5 per 100 py for women and men, respectively (rate ratio [RR] = 2.0, CI: 0.28-22.1). In concordant-negative couples, seroincidence rates were 0.17 per 100 py in women and 0.45 per 100 py in men (RR = 0.38, CI: 0.12-1.04). Individuals living in discordant couples were at a greatly increased risk of infection compared with individuals in concordant-negative couples (RR = 57.9, CI: 12.0-244 for women; RR = 11.0, CI: 1.2-47.5 for men). CONCLUSION: Men were more likely than women to introduce HIV infection in concordant-negative partnerships. In discordant couples, incidence in HIV-negative women was twice as high as in men. HIV-negative individuals in discordant partnerships are at high risk of infection, and preventive interventions targeted at such individuals are urgently needed.     

Reducing HIV-risk behavior among adults receiving outpatient psychiatric treatment: results from a randomized controlled trial

This study investigated the efficacy of a 10-session, HIV-risk-reduction intervention with 221 women and 187 men receiving outpatient psychiatric care for a mental illness. Patients were randomly assigned to the HIV intervention, a structurally equivalent substance use reduction (SUR) intervention, or standard care; they were assessed pre- and postintervention and at 3- and 6-month follow-ups. Patients receiving the HIV-risk-reduction intervention reported less unprotected sex, fewer casual sex partners, fewer new sexually transmitted infections, more safer sex communications, improved HIV knowledge, more positive condom attitudes, stronger condom use intentions, and improved behavioral skills relative to patients in the SUR and control conditions. Patients receiving the SUR intervention reported fewer total and casual sex partners compared with control patients. Exploratory analyses suggested that female patients and patients diagnosed with a major depressive disorder were more likely to benefit from the HIV-risk-reduction intervention.     

Unprotected sex among HIV-positive injection drug-using women and their serodiscordant male partners: role of personal and partnership influences

We investigated the characteristics of human immunodeficiency virus (HIV)-positive injection drug-using women who reported unprotected vaginal and/or anal sex with HIV-negative or unknown serostatus (serodiscordant) male partners. Of 426 female study participants, 370 were sexually active. Of these women, 39% (144/370) and 40% (148/370) reported vaginal and/or anal sex with serodiscordant main and casual partners, respectively. Sixty percent of women inconsistently used condoms with their serodiscordant main partners, whereas 53% did so with casual partners. In multivariate analysis, during sex with main partners, inconsistent condom users were less likely to feel confident about achieving safe sex (self-efficacy), personal responsibility for limiting HIV transmission, and that their partner supported safe sex. Inconsistent condom use was also more likely among women who held negative beliefs about condoms and in couplings without mutual disclosure of HIV status. Regarding sex with casual partners, inconsistent condom users were more likely to experience psychologic distress, engage in sex trading, but they were less likely to feel confident about achieving safe sex. These findings suggest that there are widespread opportunities for the sexual transmission of HIV from drug-using women to HIV-uninfected men, and that reasons vary by type of partnership. Multifaceted interventions that address personal, dyadic, and addiction problems are needed for HIV-positive injection drug-using women.     

Internalized heterosexism among HIV-positive, gay-identified men: implications for HIV prevention and care

Internalized heterosexism (IH), or the internalization of societal antihomosexual attitudes, has been consistently linked to depression and low self-esteem among gay men, and it has been inconclusively associated with substance use and sexual risk in gay and bisexual men. Using structural equation modeling, the authors tested a model framed in social action theory (C. K. Ewart, 1991, 2004) in which IH is associated with HIV transmission risk and poor adherence to HIV antiretroviral therapy (ART) through the mechanisms of negative affect and stimulant use. Data from a sample of 465 gay-identified men interviewed as part of an HIV risk reduction behavioral trial were used to test the fit of the model. Results support the hypothesized model in which IH was associated with unprotected receptive (but not insertive) anal intercourse with HIV-negative or unknown HIV status partners, and with ART nonadherence indirectly via increased negative affect and more regular stimulant use. The model accounted for 15% of the variance in unprotected receptive anal intercourse and 17% of the variance in ART nonadherence. Findings support the potential utility of addressing IH in HIV prevention and treatment with HIV-positive gay men.     

Transmission behaviors of recently HIV-infected men who have sex with men

OBJECTIVES: Analyze postdiagnosis behaviors of recently HIV-infected men who have sex with men (MSM). METHODS: Recently HIV-infected MSM were interviewed at 6 weeks (n = 153) and 3 months (n = 113) after diagnosis. Behaviors from baseline to follow-up were compared; multivariate logistic regression identified associations between baseline characteristics and behavior at follow-up. RESULTS: At follow-up, MSM reported a significantly lower mean of partners (7.9 vs. 5.2) and lower means of 1-time (1.9 vs. 0.8), unknown (3.7 vs. 2.6), and acquaintance (1.1 vs. 0.5) partners than at baseline. In multivariate analyses, unprotected anal intercourse (UAI) with the last partner at follow-up was more likely if the last partner at baseline was a main partner (odds ratio [OR] = 2.94, 95% confidence interval [CI]: 1.04 to 8.33) or HIV-positive partner (OR = 3.36, 95% CI: 1.27 to 8.88) but less likely if, at follow-up, the last partner was HIV-negative (OR = 0.28, 95% CI: 0.08 to 1.00) or of unknown HIV status (OR = 0.23, 95% CI: 0.08 to 0.71), the participant had a history of nonconsensual sex (OR = 0.25, 95% CI: 0.09 to 0.72), or the participant had more than 1 partner (OR = 0.28, 95% CI: 0.09 to 0.86). More than 1 partner at follow-up was associated with no main partner at baseline or follow-up (OR = 2.76, 95% CI: 1.12 to 6.78), more partners in the last 12 months (OR = 1.02, 95% CI: 1.01 to 1.04), and UAI with the last partner (OR = 0.36, 95% CI: 0.14 to 0.90). CONCLUSIONS: After diagnosis, some but not all recently HIV-infected MSM reduced risky sexual behavior permitting potential HIV transmission.     

Sexual risk, nitrite inhalant use, and lack of circumcision associated with HIV seroconversion in men who have sex with men in the United States

Men who have sex with men (MSM) continue to account for the largest number of new HIV infections in the United States, but limited data exist on independent risk factors for infection beyond the early 1990s. The HIV Network for Prevention Trials Vaccine Preparedness Study enrolled 3257 MSM in 6 US cities from 1995 to 1997. HIV seroincidence was 1.55 per 100 person-years (95% confidence interval: 1.23-1.95) over 18 months of follow-up. On multi-variable analysis using time-dependent covariates, independent risk factors for HIV seroconversion were increased number of reported HIV-negative male sex partners (adjusted odds ratio (AOR) = 1.14 per partner, population attributable risk (PAR) = 28%), nitrite inhalant use (AOR = 2.2, PAR = 28%), unprotected receptive anal sex with an HIV unknown serostatus partner (AOR = 2.7, PAR = 15%) or HIV-positive partner (AOR = 3.4, PAR = 12%), protected receptive anal sex with an HIV-positive partner (AOR = 2.2, PAR = 11%), lack of circumcision (AOR = 2.0, PAR = 10%), and receptive oral sex to ejaculation with an HIV-positive partner (AOR = 3.8, PAR = 7%). Having a large number of male sex partners, nitrite inhalant use, and engaging in receptive anal sex explained the majority of infections in this cohort and should be targeted in prevention strategies for MSM.