Unsafe sex in men who have sex with both men and women

Behavioral and Clinical Characteristics of Self-Identified Bisexual Men Living with HIV Receiving Medical Care in the United States-Medical Monitoring Project, 2009-2013

Nationally representative data comparing demographic, risk, and clinical information among bisexual men with other MSM or heterosexuals are lacking. We described differences in demographic characteristics, behaviors, and clinical outcomes among self-identified HIV-positive bisexual, gay, and heterosexual men receiving HIV medical care in the United States. We analyzed data from the 2009-2013 cycles of the Medical Monitoring Project (MMP), a surveillance system that provides nationally representative estimates of behavioral and clinical characteristics of adults with diagnosed HIV in medical care. Altogether, 10% (95% confidence interval [CI] 9-11) of men self-identified as bisexual, 56% (CI 51-61) as gay, and 32% (CI 28-37) as heterosexual. We observed significant differences in demographic factors, clinical outcomes, drug use, and sexual behavior among bisexual men compared with gay and heterosexual men. Providers should consider sexual identities as well as sexual behaviors when developing and implementing prevention programs.

Similarities and Differences in Sexual Risk Behaviors Between Young Black MSM Who Do and Do Not Have Sex with Females

The objective of this study is to determine whether young Black MSM who also have sex with females report similar levels of sexual risk behaviors as those not having sex with females. YBMSM (N = 400) were recruited from an STI clinic, located in the Southern U.S. Men completed an audio-computer assisted self-interview and donated specimens for STI/HIV testing. Forty-three percent recently engaged in penile-vaginal sex. They were less likely to report having concurrent partners (P = .01), unprotected fellatio (P = .04), multiple partners as a bottom (P < .02), any unprotected anal sex as a bottom (P < .013), and any anal sex (P = .007). They were equally likely to report favorable attitudes toward serosorting (P = .80), multiple male partners as a top (P = .20), unprotected anal insertive sex with males (P = .15). Frequency of sex with males as a top (P = .61) or bottom (P = .61) did not differ. Compared to YBMSM not having sex with females, those having sex with females may be exercising greater caution.

HIV infection and sexual risk among men who have sex with men and women (MSMW): a systematic review and meta-analysis

OBJECTIVES

To estimate the number of men who have sex with men and women who are HIV-positive in the United States, and to compare HIV prevalence rates between men who have sex with men and women, men who have sex with men only, and men who have sex with women exclusively.

METHODS

Following PRISMA guidelines, we conducted a systematic review and meta-analysis of reports referencing HIV prevalence and men who have sex with men and women. We searched PubMed and Ovid PsycINFO for peer-reviewed, U.S.-based articles reporting on HIV prevalence among men who have sex with men and women. We conducted event rate, effect size, moderation and sensitivity analyses.

RESULTS

We estimate that 1.0% of U.S. males are bisexually-behaving, and that 121,800 bisexually-behaving men are HIV-positive. Men who have sex with men and women are less than half as likely to be HIV-positive as men who have sex with men only (16.9% vs. 33.3%; OR = 0.41, 95% CI: 0.31, 0.54), but more than five times as likely to be HIV-positive as men who have sex with women exclusively (18.3% vs. 3.5%; OR = 5.71, 95% CI: 3.47, 9.39). They are less likely to engage in unprotected receptive anal intercourse than men who have sex with men only (15.9% vs. 35.0%; OR = 0.36, 95% CI: 0.28, 0.46). Men who have sex with men and women in samples with high racial/ethnic minority proportions had significantly higher HIV prevalence than their counterparts in low racial/ethnic minority samples.

CONCLUSIONS

This represents the first meta-analysis of HIV prevalence in the U.S. between men who have sex with men and women and men who have sex with men only. Data collection, research, and HIV prevention and care delivery specifically tailored to men who have sex with men and women are necessary to better quantify and ameliorate this population's HIV burden.

Sexual partnerships with men and women among men who have sex with men in Beijing and Chongqing, China, 2010

HIV is spreading among Chinese MSM and may possibly lead to infection of female partners. Pressure to marry may drive a greater proportion of Chinese MSM to have female partners than MSM elsewhere in the world. Measurement of the size of the potential risk to female partners of Chinese MSM is inconsistent in the literature. From samples of MSM in two Chinese cities, we documented numbers of sexual partners and sexual activity with those partners. About 500 MSM were sampled in each city. 11.0 and 12.6 % of men reported having any female partners in the past 6 months in Chongqing and Beijing, respectively. Men also reported that only 7.3 and 6.7 % of their entire partnerships were with women in Chongqing and Beijing, respectively. Defining transmission risk accounting for receptive anal sex among men and condom non-use with both male and female partners, 3.4 % of MSM in both Chongqing and Beijing would have the potential to transmit HIV to female partners. Only 9 (1.8 ) men in Chongqing and 2 (0.4 %) in Beijing were HIV-positive and also had unprotected intercourse with females. The majority of HIV transmission risk among MSM in China is not from MSM to females.

Men who report recent male and female sex partners in Cape Town, South Africa: an understudied and underserved population

The HIV/AIDS epidemic in South Africa has largely focused on the needs of heterosexual men and women. However, little is known about the sexual risk histories of men who have sex with both men and women (MSMW). Furthermore, we know very little about the psychosocial health needs or of the possibility of a syndemic (numerous interrelated epidemics) among MSMW. We surveyed 1,203 men attending drinking establishments in a township located in Cape Town, South Africa. We compared the behaviors and experiences of MSMW to men reporting only having sex with women (MSW). Twelve percent of the sample reported having sex with both men and women in the past 4 months. MSMW were twice as likely as MSW to report being HIV positive (10.5 vs. 4.6 %). MSW were more likely to be married than MSMW but reported similar numbers of female sex partners. MSMW were more likely to report a history of childhood sexual abuse, recent experienced and perpetrated physical and sexual partner violence, both receiving and giving sex for money, drugs, or shelter, and a recent STI. These factors were found to be interrelated among MSW but not MSMW. Although MSMW demonstrate considerable risk taking and report higher rates of HIV infection than MSW, their needs are largely unmet and underemphasized. Findings suggest the need to better understand factors contributing to sexual risk taking among MSMW. HIV prevention interventions should consider psychosocial health problems unique to MSMW residing in South African townships.

HIV risk among men who have sex with men only (MSMO) and men who have sex with men and women (MSMW) in Baltimore

Men who have sex with men and women (MSMW) are at high risk for HIV. However, the majority of research on populations of men who have sex with men (MSM) combines MSMW and men who have sex with men only (MSMO) samples, which limits our understanding of HIV risk behaviors and factors associated with HIV risk among MSMW populations. We used the BESURE-MSM2, a venue-based cross-sectional study of HIV risk behaviors among MSM in Baltimore, MD, to examine HIV risk among MSMW. MSMW were less likely to report unprotected receptive anal intercourse than MSMO (6.8% vs. 19.6%, p = .0024). Among MSMW, 43.0% reported unprotected sex with a woman in the past year, but only 19.4% reported unprotected sex with both men and women, representing only 5.0% of the total MSM sample. In multivariate analyses, we found that among MSMW having unprotected sex with women in the past year, disclosing same sex behavior and having a main female partner were associated with unprotected anal intercourse with male partners. HIV prevention programs for MSMW are needed that address the complex partnerships of MSMW and the social contextual factors within which relationships and behaviors are embedded.

Male injecting drug users in the Deep South: bisexual behaviour is a marker for elevated HIV risk

This study determined whether bisexual male injecting drug users (IDUs) as compared with heterosexual IDUs were more likely to engage in HIV-associated risk behaviours. Respondent-driven sampling was employed to recruit a sample of 382 male IDUs residing in the southeastern USA. Data were collected in face-to-face interviews. Weighted analyses showed that bisexual IDUs in the past 12 months were 4.6 times as likely to share needles and 3.5 times as likely to share a cooker; having multiple female sexual partners and trading money or drugs for sex with women were marginally significant. Bisexual IDUs were 10 times as likely to self-report HIV. Male IDUs, who engage in bisexual behaviour, are also engaging in HIV-associated drug and to some degree sexual-risk behaviours with women more so than heterosexual IDUs. Their higher prevalence of HIV infection coupled with their risk behaviours place themselves and other IDUs at heightened risk of both acquiring and transmitting HIV.

Sexual Risk Behaviors with Female and Male Partners Met in Different Sexual Venues Among Non-Gay-Identified, Non-Disclosing MSMW

Despite considerable interest in the sexual behavior of non-disclosing men who have sex with men and women (MSMW), little is known about where they meet their male and female partners and whether their sexual risk behavior differs with partners met in different sexual venues (e.g., bars, Internet, parks). These issues were examined among 46 non-gay-identified MSMW who had not disclosed their same-sex behavior to female partners (i.e., men on the "down low"). The prevalence of unprotected vaginal sex was nearly identical with women met in bars/clubs as with women met through friends, work, or the neighborhood. In contrast, the prevalence of unprotected anal sex was higher with male partners met on the Internet, in bars/clubs, and through friends/work/neighborhood as compared with partners met in parks/restrooms or gyms. This is largely due to MSMW avoiding anal sex in parks, restrooms, and gyms, in favor of oral sex. These findings provide important insights into the role of venues on sexual risk and the locations where risk reduction interventions for MSMW may be provided.

Sexual behavior and risk factors for HIV infection among homosexual and bisexual men in Thailand

HIV prevalence and associated risk behaviors were examined among Thai bisexually active men (MSMW, n = 450) and men who have sex with men only (MSM-only, n = 1,125). Cross sectional venue-day-time sampling was used to collect data. Chi-square and logistic regression were used to identify HIV risk factors. HIV prevalence was 8.2% among MSMW and 21.2% among MSM-only. Consistent condom use with male partners was higher among MSMW (77.6%) than MSM-only (62.9%), and lower with female partners (44.4%). Lack of family confidant, migration, concern about acquiring HIV infection, and self-reported STD were associated with HIV prevalence among MSMW. Older age, lower educational level, residing in Bangkok or Chiang Mai, living away from family, recruitment from a sauna, increased frequency of visiting the surveyed venue, practicing receptive or both receptive and insertive anal intercourse, inconsistent condom use with male paying partners, and a history of drug use were associated with HIV prevalence in MSM-only.

Psychosocial correlates of unprotected sex without disclosure of HIV-positivity among African-American, Latino, and White men who have sex with men and women

African-American, Latino, and White men who have sex with men and women (MSMW) may be a bridge of HIV transmission from men to women. Very little research has directly compared culturally specific correlates of the likelihood of unprotected sex among MSMW. The present study examined psychosocial correlates of unprotected sex without disclosure of HIV status with male and female partners among 50 African American, 50 Latino, and 50 White HIV-positive MSMW recruited from AIDS service organizations in Los Angeles County. Multivariate logistic regressions were conducted to examine relationships of race/ethnicity and psychosocial variables (e.g., condom attitudes, self-efficacy for HIV disclosure, sexual identification) to unprotected sex without disclosure of HIV status, for male and female partners separately. For female partners, different effects emerged by race/ethnicity. Among African-Americans, less exclusively homosexual identification and low self-efficacy for disclosure of HIV status to female partners were associated with unprotected sex without disclosure; among Latinos, less exclusively homosexual identification and negative attitudes about condoms were significant. Participants who were more exclusively homosexually identified, who held less positive condom attitudes, and who had low self-efficacy for disclosure to female partners were more likely to have unprotected sex without disclosure of HIV status to male partners. Culturally tailored community-level interventions may help to raise awareness about HIV and bisexuality, and decrease HIV and sexual orientation stigma, thereby increasing African-American and Latino MSMW's comfort in communicating with their female partners about sexuality, HIV and condoms. Addressing norms for condom use and disclosure between male partners is recommended, especially for homosexually identified MSMW.

Beyond the Down Low: sexual risk, protection, and disclosure among at-risk Black men who have sex with both men and women (MSMW)

Little information is available about sexual risk, protective, and disclosure practices among Black bisexually active men and how these may be amenable to intervention when necessary. In-depth interviews were conducted with 30 at-risk urban Black men who have sex with both men and women (MSMW). Participants reported protecting themselves and their partners through routine HIV testing, using condoms consistently, engaging in strategic positioning during sexual activity, and limiting the number of sexual partners. In addition, they described several reasons for not using protection, including not having condoms available, enjoying sexual activity more without condoms, and perceiving female partners to be "safer" than male partners. Disclosure of bisexuality was complex and reportedly difficult, in particular to female and gay-identified male partners. Future interventions must not only build protection and disclosure skills among MSMW, but also increase broader social awareness and acceptance of male bisexuality.

Sexual behaviors of non-gay identified non-disclosing men who have sex with men and women

The sexual behaviors of non-gay identified men who have sex with men and women (MSMW) who do not disclose their same-sex behavior to their female partners (referred to by some as men "on the down low") were examined, including the potential for these men to serve as a "bisexual bridge" for HIV and STD acquisition and transmission. Self-reported sexual behavior data were collected as part of an exploratory study of an ethnically diverse (41% African American, 35% Latino, 22% White, and 2% Asian) sample of 46 non-gay identified, non-disclosing MSMW in New York City. Men reported significantly more male than female sexual partners, but more frequent sex with females. The prevalence and frequency of unprotected sex did not differ significantly between male and female partners in the past 3 months. Men reported risk behavior more often with steady female and steady male partners (e.g., wives, girlfriends, boyfriends) than with more casual male and female partners (regular uncommitted partners, one-night stands). Men, especially African American/Black men, were significantly less likely to report receptive sexual behaviors with men than insertive behaviors. Unprotected sex was common with male and female partners in the past 3 months (e.g., 35% of anal sex with men; 50% of vaginal sex). Indeed, 22% of the sample (38% of those who had both recent males and female partners) reported both unprotected vaginal sex and unprotected anal sex with a male partner during the past 3 months. Although the study was limited by a small convenience sample, the findings suggest that non-gay identified non-disclosing MSMW are at risk for the acquisition and transmission of HIV and STDs, and may serve as a potential bridge, suggesting the need for further research and intervention targeting this unique population.

The cost-effectiveness of counseling strategies to improve adherence to highly active antiretroviral therapy among men who have sex with men

OBJECTIVE

Inadequate adherence to highly active antiretroviral therapy (HAART) may lead to poor health outcomes and the development of HIV strains that are resistant to HAART. The authors developed a model to evaluate the cost-effectiveness of counseling interventions to improve adherence to HAART among men who have sex with men (MSM).

METHODS

The authors developed a dynamic compartmental model that incorporates HIV treatment, adherence to treatment, and infection transmission and progression. All data estimates were obtained from secondary sources. The authors evaluated a counseling intervention given prior to initiation of HAART and before all changes in drug regimens, combined with phone-in support while on HAART. They considered a moderate-prevalence and a high-prevalence population of MSM.

RESULTS

If the impact of HIV transmission is ignored, the counseling intervention has a cost-effectiveness ratio of $25,500 per quality-adjusted life year (QALY) gained. When HIV transmission is included, the cost-effectiveness ratio is much lower: $7400 and $8700 per QALY gained in the moderate- and high-prevalence populations, respectively. When the intervention is twice as costly per counseling session and half as effective as estimated in the base case (in terms of the number of individuals who become highly adherent, and who remain highly adherent), then the intervention costs $17,100 and $19,600 per QALY gained in the 2 populations, respectively.

CONCLUSIONS

Counseling to improve adherence to HAART increased length of life, modestly reduced HIV transmission, and cost substantially less than $50,000 per QALY gained over a wide range of assumptions but did not reduce the proportion of drug-resistant strains. Such counseling provides only modest benefit as a tool for HIV prevention but can provide significant benefit for individual patients at an affordable cost.

Bisexual Latino men and HIV and sexually transmitted infections risk: an exploratory analysis

OBJECTIVES

We sought to determine whether there were differences in sexual risk among behaviorally and self-identified bisexual men, men who reported having sex with both men and women without reporting a bisexual identity and men who self-identified as bisexual but reported only recent homosexual behavior over the past 6 months.

METHODS

secondary data analysis, we conducted stepwise linear regression equation modeling to determine which factors were significant predictors of sexual risk among various subgroups of bisexual Latino men.

RESULTS

Having sex with women, regardless of sexual identity, increased the likelihood of insertive unprotected anal intercourse with men. Bisexual identity was not statistically associated with unprotected anal intercourse with men.

CONCLUSIONS

Future studies should begin to examine differences within groups rather than focusing on group comparisons that yield limited insights into sexual risk predictors for homosexually and bisexually active men. Further research that explores risk and protective factors in the sexual lives of Latino bisexual men is also needed.

Sex with women as a risk factor for herpes simplex virus type 2 among young men who have sex with men in Baltimore

BACKGROUND

Herpes simplex virus type 2 is common among MSM and is a risk factor for transmission of HIV. The findings of studies investigating the relationship between infection with HSV-2 and number of sex partners among MSM are inconsistent and rarely distinguish between male and female partners.

GOAL

To determine the prevalence and risk factors for infection with HSV-2, including the number and gender of sex partners, in a group of MSM in Baltimore, MD.

STUDY

This was a cross-sectional study among young MSM in Baltimore.

RESULTS

Of the blood samples from 824 participants, 19.3% had HSV-2 antibodies. After adjusting for known HSV-2 correlates, independent predictors of HSV-2 seropositivity included HIV seropositivity, black race, older age, number of lifetime female sex partners, recent unprotected receptive anal intercourse with a man.

CONCLUSIONS

This study suggests that female sex partners may be an important source of HSV-2 infection among young bisexual MSM. After adjusting for known HSV-2 correlates, the number of lifetime female but not male sex partners was independently associated with HSV-2. These results highlight the need for HSV-2 prevention and treatment efforts targeting MSM who also have sex with women. Future investigations of HSV-2 and sexual behavior among MSM need to distinguish between male and female sex partners.

Spatial bridging in a network of drug-using male sex workers

This study sought to determine whether drug-using male sex workers (MSWs) spatially bridge sexual networks across cities and to determine whether the behaviors of MSWs who bridge differ from the behaviors of those who do not. Data were collected from 42 MSWs in Houston, Texas, between May 2003 and February 2004. Spatial bridging was defined as having traded sex for money in another city before traveling to and trading in Houston. Cities bridged by MSWs were geographically plotted and were primarily located in the Gulf Coast and in Florida. Slightly less than half of MSWs were identified as spatially bridging from one city to another. A significantly higher proportion of MSWs who bridged cities were homosexual (55% vs. 23%) and HIV positive (31% vs. 5%). Those who bridged cities used marijuana and injected drugs more frequently and had significantly more male sex partners than MSWs who did not bridge cities. Despite the small sample size, this study found that many drug-using MSWs spatially bridge sexual networks in cities where they trade sex for money.

Gay Identity, Interpersonal Violence, and HIV Risk Behaviors: An Empirical Test of Theoretical Relationships among a Probability-Based Sample of Urban Men Who Have Sex with Men

The highest absolute number of new HIV infections and AIDS cases still occur among men who have sex with men (MSM). Numerous theoretical approaches have been used to understand HIV risk behaviors among MSM; however, no theoretical model examines sexual risk behaviors in the context of gay identity and interpersonal violence. Using a model testing predictive correlational design, the theoretical relationships between childhood sexual abuse, adverse early life experiences, gay identity, substance use, battering, aversive emotions, HIV alienation, cue-to-action triggers, and HIV risk behaviors were empirically tested using confirmatory factor analysis and structural equation modeling. The relationships between these constructs are complex, yet childhood sexual abuse and gay identity were found to be theoretically associated with HIV risk behaviors. Also of importance, battering victimization was identified as a key mediating variable between childhood sexual abuse, gay identity, and adverse early life experiences and HIV risk behaviors among urban MSM.

Inconsistent condom use among HIV-infected patients with alcohol problems

BACKGROUND

Unsafe sexual behavior is common among persons with negative or unknown HIV status and it is augmented by alcohol use in some populations. We examined the association between alcohol consumption level (abstinent, moderate, at-risk) and inconsistent condom use in a cohort of HIV-infected individuals with a history of alcohol problems.

METHODS

Subjects (n=345) had up to seven structured interviews over 36 months. Identical questions on alcohol consumption and inconsistent condom use were asked at each interview. We used generalized estimating equations (GEE) multivariate logistic regression for repeated measurements analysis. We adjusted for potential confounding factors and explored possible interactions.

RESULTS

At baseline, 132 (38%) participants reported inconsistent condom use. We detected a significant (P=0.0002) interaction between alcohol consumption and injection drug use (IDU) variables. Among active injection drug users, at-risk drinking was associated with inconsistent condom use, adjusted odds ratio (OR; 95% confidence interval) 4.3 (1.5, 12.2). Among those who did not inject drugs, at-risk drinking and inconsistent condom use were not associated, 0.7 (0.4, 1.3). Inconsistent condom use was more common among women, those believing condoms to be 'a hassle', and persons living with a partner.

CONCLUSION

In HIV-infected drug-injecting individuals, excessive use of alcohol is associated with unsafe sexual practices.

Drug injection and sexual mixing patterns of drug-using male sex workers

BACKGROUND

Drug-using male sex workers (DUMSWs) are known to have large numbers of drug injection and sex partners.

GOALS

The purpose of this study was to describe the assortative and disassortative drug injection and sexual mixing patterns of DUMSWs. Implications of the high rates of disassortative mixing patterns of DUMSWs for HIV infection are discussed. Implications of disassortative mixing of DUMSWS with regard to DUMSWs bridging disparate HIV risk groups are evaluated.

STUDY DESIGN

Data were collected from 89 DUMSWS. Data on up to six drug injection and six sex partners were collected from respondents. One hundred drug injection and 169 sex respondent/partner pairs were analyzed for the proportions of pairs that were concordant (like) or discordant (unlike) in gender, trading sex for money, race/ethnicity, and age cohort. For race/ethnicity and age, within-group differences were assessed with chi-square statistics.

RESULTS

Data showed high proportions of discordant respondent/partner pairs for both drug injection and sex by gender, trading sex for money, race/ethnicity, and age. Significant within-group differences in rates of discordant pairs were found for both behaviors in relation to race/ethnicity and age. Minority persons and respondents 19 years of age or younger were more likely to be in discordant pairs.

CONCLUSIONS

Direct assessment of HIV risk posed by the mixing patterns was not possible. Elaborating the mechanisms by which DUMSWs might act as an epidemiologic bridge is complex and involves more variables than were explored in this study. Nevertheless, such a study would be worthwhile.

Risk among young gay and bisexual men living with HIV

The influence of sexual orientation was examined on sexual risk behaviors, disclosure patterns, substance use, and stressful live events among 231 gay and bisexual youth living with HIV. Youth were mainly of ethnic minority heritage: 69.3% were Hispanic, African American, or biracial. Although there were significant differences in gay and bisexual youth's self-label and patterns of sexual attraction and sexual partners, there were few differences in other behavioral risk acts. The frequency of sexual risk acts, substance use, stressful life events, and child sexual abuse were similar for gay and bisexual youth and similar across ethnic groups. Disclosure of sexual orientation was significantly more common among gay youth compared with bisexual youth. Gay and bisexual identification appears to be a more critical factor than ethnicity in placing youth at risk for HIV. Care providers need to screen youth for sexual orientation and behaviors at a young age and inquire about age of partners, substance use, and history of sexual abuse.

Case-crossover study of partner and situational factors for unprotected sex

OBJECTIVES

To identify situational and partner characteristics associated with unprotected sex among women at risk for HIV infection.

METHODS

The most recent unprotected and protected sexual encounters were compared using a case-crossover design among 1,647 women enrolled in a prospective cohort study conducted in six U.S. cities. Information collected via audio computer-assisted self-interview included detailed situational and partner characteristics for participants' most recent sexual encounters, with and without condom use. Paired odds ratios (ORs) and 95% confidence intervals were calculated for situational or partner characteristics that may differ between unprotected and protected sexual encounters, using conditional logistic regression.

RESULTS

In the adjusted analysis, partner age of older than 40 years (OR = 2.42), partner type (OR = 2.45 for a "steady" partner), partner use of alcohol (OR = 1.67) and drugs within 2 hours (OR = 1.42) of the sexual encounter, time since the encounters (OR = 0.41, 0.33, and 0.19), and exchange of sex for money or drugs (OR = 0.68) remained significantly associated with women's most recent unprotected sexual encounter.

CONCLUSIONS

Considerations related to partner and relationship characteristics should provide information for the development of interventions for women.

Heterosexual anal intercourse: prevalence, cultural factors, and HIV infection and other health risks, Part I

Studies of heterosexual HIV transmission have consistently found anal intercourse to be a highly predictive risk factor for seroconversion. Yet most AIDS prevention messages targeted at heterosexuals, presumably influenced by cultural taboos against acknowledging this sexual practice, continue to emphasize vaginal and, increasingly, oral sex transmission. The health risks of anal sex appear to be severely underestimated by a substantial proportion of sexually active women and men in North and Latin America as well as parts of South Asia, Africa, and other regions. Among heterosexuals reported rates of condom use are nearly universally lower for anal than for vaginal intercourse. This review examines anal sex among the general population, including its prevalence in various world regions, related sociocultural factors, and other associated health problems including anorectal STDs, Hepatitis B infection, and HPV-related anal cancer in women. U.S. survey and other data suggest that, in terms of absolute numbers, approximately seven times more women than homosexual men engage in unprotected receptive anal intercourse. Research among higher risk subpopulations, including bisexual men, injecting drug users, female sex workers, inner-city adolescents, and serodiscordant heterosexual couples, indicates that persons particularly at risk of being infected by or transmitting HIV are also more likely to practice anal sex. Considering this finding, along with the much greater efficiency for HIV infection as well as lower rates of condom usage, a significant proportion of heterosexual transmission in some populations is due to anal intercourse. This typically stigmatized and hidden sexual practice must be given greater emphasis in AIDS/STD prevention, women's care, and other health promotion programs.