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Overcoming Biological, Behavioral, and Structural Vulnerabilities: New Directions in Research to Decrease HIV Transmission in Men Who Have Sex With Men

Mayer, Kenneth H. MD*,†; Wheeler, Darrell P. PhD, MPH; Bekker, Linda-Gail MBChB, FCP(SA), PhD§; Grinsztejn, Beatriz MD, PhD; Remien, Robert H. PhD¶,#; Sandfort, Theodorus G. M. PhD**; Beyrer, Chris MD, MPH††

JAIDS Journal of Acquired Immune Deficiency Syndromes: July 1st, 2013 - Volume 63 - Issue - p S161–S167
doi: 10.1097/QAI.0b013e318298700e
Supplement Article

Abstract: Men who have sex with men (MSM), including transgender women, comprise a heterogeneous group of individuals whose sexual behaviors and gender identities may vary widely between cultures and among individuals. Their sources of increased vulnerability to HIV are diverse, including the increased efficiency of HIV transmission via unprotected anal intercourse, sexual role versatility, asymptomatic sexually transmitted infections, and behavioral factors that may be associated with condomless sex with multiple partners. Societal stigmatization of homosexual behavior and gender nonconformity may result in internalized negative feelings that lead to depression, other affective disorders, and substance use, which in turn are associated with increased risk-taking behaviors. Social stigma and punitive civil environments may lead to delays in seeking HIV and sexually transmitted disease screening, and later initiation of antiretroviral therapy. The iPrEX study demonstrated that chemoprophylaxis can decrease HIV acquisition in MSM, and the HIV prevention trials network 052 study established the biological plausibility that earlier initiation of highly active antiretroviral therapy can decrease HIV transmission to uninfected partners. Despite these advances, MSM remain among the most significantly HIV-affected population in resource-rich and limited settings. New studies will integrate enhanced understanding of the biology of enhanced rectal transmission of HIV and the focused use of antiretrovirals for prevention with culturally tailored approaches that address the potentiating social and behavioral factors associated with enhanced HIV spread among MSM.

*Faculty of Medicine, Harvard Medical School;

HIV Prevention Research, Beth Israel Deaconess Medical Center, Fenway Health, Boston, MA;

School of Social Work, Loyola University Chicago, Chicago, IL;

§The Desmond Tutu HIV Centre, IIDMM, Department of Medicine, University of Cape Town, Cape Town, South Africa;

Fundação Oswaldo Cruz, Rio de Janeiro, Brazil;

Division of Clinical Psychology, Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, NY;

#HIV Center for Clinical and Behavioral Studies, New York State Psychiatric Institute and Department of Psychiatry, Columbia University Medical Center, New York, NY;

**Division of Gender, Sexuality, and Health, New York State Psychiatric Institute and Department of Psychiatry, Columbia University, New York, NY; and

††Center for Public Health and Human Rights, The Johns Hopkins Bloomberg School of Public Health.

Correspondence to: Kenneth H. Mayer, MD, Harvard Medical School, Infectious Disease Attending and Director of HIV Prevention Research, Beth Israel Deaconess Medical Center, Medical Research Director, Fenway Health, 1340 Boylston Street, Boston, MA 02215 (e-mail:

The authors have no conflicts of interest to disclose.

Funding support provided by the HIV Prevention Trials Network through the following award (UM1 AI068619).

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The global HIV/AIDS epidemic was first recognized among men who have sex with men (MSM) in the early 1980s,1,2 and people who are born male who have sex with other men have remained at high risk for HIV acquisition ever since.3 Because of the biological susceptibility,4 a high concomitant sexually transmitted disease (STD) burden, and ongoing risk-taking behavior, in many parts of the world, MSM continue to be one of the populations with the greatest HIV incidence.3 MSM represent a substantial proportion of those infected with HIV in many resource-constrained environments, including those with generalized epidemics.5 MSM may be vulnerable to syndemics, the co-occurence of health disparities, which potentiate HIV risk6 and are exacerbated by societal stigma.7 The demonstration that antiretroviral chemoprophylaxis decreased HIV incidence among MSM8 offers new opportunities for HIV prevention. HIV prevention trials network (HPTN) 052 has suggested that early identification of HIV infection and highly active antiretroviral therapy (HAART) initiation could decrease HIV transmission in heterosexuals,9 which should be relevant for MSM. Reducing HIV incidence in MSM will require multicomponent and culturally tailored interventions integrating scientific insights with community engagement that address their diversity.

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Receptive anal intercourse is the most efficient sexual practice transmitting HIV.4 MSM engaging in insertive anal sex can become HIV infected, particularly if the partner has an STD, is untreated, or is uncircumcised. Because many MSM are sexually versatile, they can acquire HIV as the receptive partner, but after becoming infected, they may transmit to a new partner when they are insertive. Among some sexually active MSM, additional potentiators of transmission are frequent partner exchange, group sex, or other traumatic practices. For other MSM, their individual risk practices may involve anal intercourse in the setting of long-term or serial monogamy, but they may have selected a nonmonogamous partner and/or a partner from a subpopulation with high HIV prevalence (eg, black MSM in the United States).10–12

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Sequelae of Stigma

Internalized homophobia is associated with an increased risk for HIV acquisition and transmission due in part to increased risk behaviors and decreased engagement in prevention and care.17,18 Internalized homophobia has been linked to depression, low self-esteem, and feelings of loneliness as well as disregard for partners' and individual’s health, leading to unsafe sex.18,19 Accompanying distress may lead to substance abuse to mask the feelings of shame.19 The use of alcohol and other recreational drugs has been associated with having multiple partners and sex work, amplifying risks.20

Structural factors, such as low education, unemployment, and poverty, may also be related to HIV risk and infection.10,21,22 Societal rejection and criminalization of homosexuality is a crucial structural factor associated with HIV risk in MSM. In the United States, black MSM who experienced homophobic events were more likely to be HIV infected and to engage in unprotected sex.23 Experienced discrimination may potentiate the adverse health outcomes.24 Structural factors may impede MSM access to condoms and HIV/STD testing and to HIV care.25–28

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Physical and Virtual Venues

MSM socialize and find sexual partners in a variety of places, including bars/clubs, bathhouses, parks, and online.29 Some studies found sexual risk behaviors more prevalent in specific venues, whereas others did not.30–36 Social norms may differ by venue. For instance, HIV status disclosure was high among men who met their most recent partner online and lower among men who met their most recent partner in a public place.32 Some venues, for example, bathhouses, can enhance HIV prevention initiatives,37 including onsite HIV and STD screening.38

Advances in electronic communication may affect HIV prevention in negative and positive ways.39–41 Social media enhance the ease to meet potential sexual partners, including those who prefer unprotected sex,42–44 although studies differ in correlating Internet use with unprotected intercourse.45–48 E-dating seems more prevalent among MSM who live in nonurban areas.49 Internet sexual behavior seems to be highly correlated with MSM's behavior offline.50–55 E-technologies also facilitate engagement of hard-to-reach populations in accessing sexual health information55–57 and can facilitate HIV prevention.58–61

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Treatment as Prevention

HPTN 052 demonstrated that earlier initiation of HAART in asymptomatic HIV-infected individuals decreased their likelihood of HIV transmission to their uninfected primary partner by 96%.9 However, only 3% of enrollees were MSM. HIV may be detected in rectal secretions of MSM with undetectable plasma viremia, although the clinical significance of low copy numbers requires further study.61 Ecological data from areas where treatment access is high and where MSM have constituted the largest numbers of new infections have been mixed, with decreases in HIV incidence seen among MSM in San Francisco62 but not in London.63 Observational studies of MSM couples are underway in Europe and Australia. However, other data suggest that “test-and-treat” approaches could decrease HIV incidence in MSM. Individuals who are aware of their HIV status are less likely to engaging in potential transmitting behaviors64 and successful suppression of plasma viremia with HAART being associated with marked reductions in the detection of seminal HIV.65,66 Additionally, those who initiated treatment sooner in HPTN 052 had better clinical outcomes,67 and large observational studies also indicate that earlier treatment results in decreased morbidity.68 Operational questions remain, given that social stigma may result in delays in accessing testing and treatment services. Earlier HIV identification through self and partner testing69,70 may enhance prevention efforts.

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At present, substantial numbers of MSM are unaware of their HIV status. The most optimistic test, link, and treat programs will take years to have an appreciable impact in lowering community viral load for MSM. To have maximal impact, wider expansion of testing and earlier treatment for HIV-infected MSM, accompanied by focused programs of chemoprophylaxis for the riskiest MSM, may be most efficient in arresting HIV spread among MSM.

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Although MSM engage in similar practices, the term defines a transmission category, without recognizing the diverse identities, behaviors, and social realities that it includes. To address the global AIDS epidemic, an understanding that different MSM subcultures require tailored interventions to achieve “an AIDS-free generation.”

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MSM in Africa

Although sub-Saharan Africa was long believed to have an exclusively heterosexual epidemic, recent research indicates that the risk of being HIV infected is higher among MSM than among heterosexual African men. HIV prevalence rates of up to 50% have been described,71–83 with 1 study reporting an incidence of 8.6 per 100-person years in Kenyan MSM.80 Several studies have reported high rates of bisexual behavior among African MSM, and 1 report noted a high rate of bisexual concurrency (being sexually active with both a man and a woman in the same period) among MSM in Malawi, Namibia, Senegal, and Botswana.81–85

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MSM in Latin America

Across Latin America, the HIV epidemic is concentrated in MSM with HIV prevalence estimates between 7.9% and 21.2%, 33.3 times higher than that in the general population.72 Transgender women (TGW) are at an even greater risk of HIV acquisition, with HIV prevalence estimates between 18.8% and 33.5% in Uruguay and Argentina, respectively. Compared to Latin American adults aged 15–49 years, TGW are 50-fold more likely to be HIV infected.86 Although HIV prevention and treatment efforts have improved, efforts to control the spread of the disease among MSM have been hampered by poverty, inadequate health services, stigma, discrimination, violence, homophobia, and transphobia.87,88 Modeling data from Peru suggest that earlier treatment initiation and improved treatment adherence must be integrated into comprehensive HIV prevention.5

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MSM in Asia

HIV in Asia is a concentrated epidemic, with disproportionate rates of HIV infection being found among MSM in virtually all the countries where it has been studied.89 Social stigmatization of homosexuality and negative effect because of the pressure to have a wife and children has been associated with HIV risk behaviors in several Asian settings.90–92 Successful social mobilization campaigns like the Avahan initiative in India suggest that community engagement can help to attenuate HIV spread,93 but recent data from Thailand suggest that high rates of new infections are being noted in younger MSM, often in conjunction with nonparenteral recreational drug use.91 Asia has perhaps the greatest cultural diversity of same sex identities and social expressions of same sex behavior.94,95 Many of the traditional categories of gender roles, including the Hijra of south India and the Koetey of southeast Asia, include feminized categories of males who are seen as quite different from gay-identified or homosexual men, and for whom outreach requires targeted and culturally appropriate programs.

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Racial and ethnic minority MSM may experience dual stigmas due to homophobia and racism. For example, black MSM in the United States have the highest HIV concentration of any subpopulation, but they have not been found to engage in higher levels of risk-taking behavior than other MSM.10 Recent data have found HIV-incidence rates of close 3% annually in a 6-city study of black MSM, with the incidence being higher in younger, gay-identified black MSM.12

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Adolescent and Young Adult MSM

Self-acceptance of sexual identity leads to healthful outcomes,96–98 but MSM adolescents may experience rejection, placing them at an increased risk for impaired physical, social, and emotional health.98 Although attitudes regarding homosexuality have become more supportive in many places, social stigma remains common for young MSM.99 Coming out can mean risking rejection and loss of support from family.100 MSM adolescents are more likely than heterosexual peers to experience social isolation, truancy, prostitution, substance abuse, depression, and STDs.98 Sexual experimentation and perceptions of invincibility may make young MSM at an increased risk for HIV acquisition.101 Younger MSM had an increased HIV incidence in iPrEX, consistent with decreased adherence.102,103

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Transgender Men and Women

Transgender persons have been less studied than other sexual and gender minority populations, although TGW (persons born biologically male and expressing female gender identities) have disproportionate HIV burdens. A recent global systematic review and meta-analysis about TGW in 15 countries found a pooled HIV prevalence of 19.1%,85 indicating an urgent unmet need for HIV prevention and care. There is a paucity of data regarding transgender men (born biologically female and expressing male gender identities) and HIV risks, suggesting a need for further research.

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Expanding HIV Testing

The engagement of men in HIV testing has been a challenge in many settings. HPTN 043, a randomized controlled trial comparing community-based HIV testing and counseling to clinic-based voluntary testing and counseling, showed considerable efficacy in engaging African and Thai men in HIV testing.104 Men preferred community-based and mobile voluntary testing and counseling in times and places convenient for working adults and in culturally appropriate settings. Although HPTN 043 had relatively few MSM participants, the implications suggest that expanding testing for MSM will require innovations in how testing is provided, including home testing and in entertainment settings that MSM frequent.

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Early Treatment for HIV-Infected MSM

There is a strong biological plausibility for effective ART therapy to reduce sexual transmission of HIV between men. Ecological evidence from San Francisco suggests that early HAART initiation and high levels of treatment coverage may now be having an impact on HIV incidence among MSM at population levels.65 However, recent epidemiologic and modeling data suggest that in many populations of MSM, primary partnerships may account for substantially smaller proportions among heterosexuals.89 Sexual networks may be the more relevant social level to assess the impact of ART on HIV incidence among MSM. Such an approach may require community randomized designs but could allow for definitive answers to the important question of the likely role of early ART for HIV prevention for MSM.

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Optimizing Chemoprophylaxis

iPrEX demonstrated that antiretroviral preexposure prophylaxis (PrEP) was effective in decreasing HIV incidence in MSM.8 However, MSM assigned to take emtricitabine/tenofovir had drug detected only half the time that medication levels were measured.105 For individuals with episodic risks, pericoital or intermittent fixed interval PrEP dosing is appealing because it could save costs and potentially lower the risks of toxicities. However, 1 early study of the feasibility of intermittent PrEP among MSM and female sex workers in Uganda and Kenya found that postcoital doses were often missed.106 Studies are underway in the HPTN and research teams in the United Kingdom (Medical Research Council) and France (Agence National de Recherche sur le Sida) to better understand how intermittent PrEP may be optimally deployed ( and Because anal sex among MSM often entails the use of a lubricating gel and because the CAPRISA 004 study showed that pericoital use of tenofovir gel decreased the incidence in South African women,107 it is reasonable to postulate that a rectal gel might be acceptable and efficacious. Rectally administered tenofovir gel that did not contain glycerin, which stimulated peristalsis in MTN 006,108 was found to be acceptable in MTN 007.109 An expanded multinational safety and acceptability study will evaluate the rectal gel and oral emtricitabine/tenofovir (MTN 017), and it may suggest how future chemoprophylaxis trials may be designed. Finally, although tenofovir-based chemoprophylaxis has been found to be safe, questions about chronic use remain. Others have been interested in using antiretrovirals that are not mainstays of treatment to minimize the likelihood of the selection of drug-resistant mutants that could hamper future treatment scale-up efforts. The first study of new oral regimens for chemoprophylaxis using maraviroc by itself or in combination with emtricitabine or tenofovir is currently enrolling 400 MSM at 12 US sites (HPTN 069/ACTG 5305). Further research evaluating formulations that can be given less often via injection (ie, rilpivirine and newer integrase inhibitors) are underway and could also be relevant for MSM.

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Combination Prevention Strategies

Modeling has suggested that combined approaches to the prevention may have the greatest impact in arresting the HIV epidemic among MSM.110–112 To begin the process of combining evidence approaches into culturally tailored prevention “packages” that may have the widest replicability, the National Institutes of Health has recent funded consortia to develop prevention interventions for MSM in North and South America, China, and Africa. These projects entail a number of key components, including a comprehensive literature review of current HIV prevention interventions for MSM, a modeling exercise to estimate the impact that implementing a combination HIV prevention package will have on HIV transmission, and pilot studies to explore the feasibility and acceptability of the prevention package. The package may will include condom promotion, risk reduction counseling, access to condom-compatible lubricants, linkage to care for HIV care and treatment, expanded HIV testing and counseling, and sexually transmitted infection testing and treatment, but each group will tailor additional components, such as engaging couples and/or networks, use of electronic media, and/or provision of PrEP based on preliminary studies and input from community advisory boards.

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Structural Interventions

New biobehavioral HIV interventions for MSM could be enhanced by structural interventions that decrease stigma and promote social integration of MSM. Careful analyses of the impact of changes in laws regarding marriage and other civic enfranchisement in different countries are needed to evaluate whether they are a needed part of local “prevention packages.” Interventions that address economic disparities that may potentiate risk taking (eg, conditional cash transfer for male sex workers and other economically disenfranchised MSM subpopulations) also deserve further evaluation.

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Although MSM are disproportionately affected by HIV globally, reduction in incidence will require a diverse set of interventions, based on the understanding of patterns of spread and local norms. Interventions that address stigma and associated sequelae must be culturally tailored and can be augmented with new approaches to increase HIV testing and linkage to care, early initiation of treatment, identification of transmission networks, and chemoprophylaxis. To determine the optimal prevention package, ongoing dialog with key community stakeholders remains essential, given the heterogeneity of MSM cultures and the diverse drivers of risk globally.

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1. CDC. Update on acquired immune deficiency syndrome (AIDS)–United States. MMWR Morb Mortal Wkly Rep. 1982;31:507–508, 513–4.
2. Jaffe HW, Bregman DJ, Selik RM. Acquired immune deficiency syndrome in the United States: the first 1,000 cases. J Infect Dis. 1983;148:339–345.
3. Beyrer C, Baral SD, van Griensven F, et al.. Global epidemiology of HIV infection in men who have sex with men. Lancet. 2012;380:367–377.
4. Baggaley RF, White RG, Boily MC. HIV transmission risk through anal intercourse: systematic review, meta-analysis and implications for HIV prevention. Int J Epidemiol. 2010;39:1048–1063.
5. Beyrer C, Baral SD, Walker D, et al.. The expanding epidemics of HIV type 1 among men who have sex with men in low- and middle-income countries: diversity and consistency. Epidemiol Rev. 2010;32:137–151.
6. Stall R, Leigh B. Understanding the relationship between drug or alcohol use and high risk sexual activity for HIV transmission: where do we go from here? Addiction. 1994;89:131–134.
7. Garofalo R, Herrick A, Mustanski BS, et al.. Tip of the Iceberg: young men who have sex with men, the Internet, and HIV risk. Am J Public Health. 2007;97:1113–1117.
8. Grant RM, Lama JR, Anderson PL, et al.. Preexposure chemoprophylaxis for HIV prevention in men who have sex with men. N Engl J Med. 2010;363:2587–2599.
9. Cohen MS, Chen YQ, McCauley M, et al.. Prevention of HIV-1 infection with early antiretroviral therapy. N Engl J Med. 2011;365:493–505.
10. Millett GA, Peterson JL, Wolitski RJ, et al.. Greater risk for HIV infection of black men who have sex with men: a critical literature review. Am J Public Health. 2006;96:12–18.
11. Mayer K, Wang L, Koblin B, et al.. An evolving concentrated epidemic: comparison of socioeconomic, behavioral and biological factors among newly diagnosed, previously diagnosed and HIV-uninfected black men who have sex with men in 6 U.S. cities (HPTN 061). Paper presented at: XIX International AIDS Conference (AIDS 2012); July 22–27, 2012; Washington, DC.
12. Koblin B, Mayer K, Eshleman SH, et al.. Correlates of HIV incidence among black men who have sex with men in 6 US cities (HPTN 061). Paper presented at: —AIDS 2012, XIX International AIDS Conference (HPTN 061); July 22–27, 2012; Washington, DC.
13. Fenton KA, Imrie J. Increasing rates of sexually transmitted diseases in homosexual men in Western europe and the United States: why? Infect Dis Clin North Am. 2005;19:311–331.
    14. Hatzenbuehler ML, Nolen-Hoeksema S, Erickson SJ. Minority stress predictors of HIV risk behavior, substance use, and depressive symptoms: results from a prospective study of bereaved gay men. Health Psychol. 2008;27:455–462.
      15. Herrick AL, Stall R, Chmiel JS, et al.. It gets better: resolution of internalized homophobia over time and associations with positive health outcomes among MSM. AIDS Behav. 2013;17:1423–1430.
        16. Vu L, Tun W, Sheehy M, et al.. Levels and correlates of internalized homophobia among men who have sex with men in Pretoria, South Africa. AIDS Behav. 2012;16:717–723.
          17. Delonga K, Torres HL, Kamen C, et al.. Loneliness, internalized homophobia, and compulsive Internet use: factors associated with sexual risk behavior among a sample of adolescent males seeking services at a community LGBT center. Sex Addict Compulsivity. 2011;18:61–74.
          18. Bingham TA, Harawa NT, Williams JK. Gender role conflict among African American men who have sex with men and women: associations with mental health and sexual risk and disclosure behaviors. Am J Public Health. 2013;103:127–133.
          19. Shoptaw S, Weiss RE, Munjas B, et al.. Homonegativity, substance use, sexual risk behaviors, and HIV status in poor and ethnic men who have sex with men in Los Angeles. J Urban Health. 2009;86(suppl 1):77–92.
          20. Dudley MG, Rostosky SS, Korfhage BA, et al.. Correlates of high-risk sexual behavior among young men who have sex with men. AIDS Educ Prev. 2004;16:328–340.
          21. Ayala G, Bingham T, Kim J, et al.. Modeling the impact of social discrimination and financial hardship on the sexual risk of HIV among Latino and black men who have sex with men. Am J Public Health. 2012;102:S242–S249.
          22. Diaz RM, Ayala G, Bein E. Sexual risk as an outcome of social oppression: data from a probability sample of Latino gay men in three U.S. cities. Cultur Divers Ethnic Minor Psychol. 2004;10:255–267.
          23. Jeffries WL, Marks G, Lauby J, et al.. Homophobia is associated with sexual behavior that increases risk of acquiring and transmitting HIV infection among black men who have sex with men. AIDS Behav. 2013;17:1442–1453.
          24. Newcomb ME, Mustanski B. Moderators of the relationship between internalized homophobia and risky sexual behavior in men who have sex with men: a meta-analysis. Arch Sex Behav. 2011;40:189–199.
          25. Ross MW, Mattison AM, Franklin DR. Club drugs and sex on drugs are associated with different motivations for gay circuit party attendance in men. Subst Use Misuse. 2003;38:1173–1183.
          26. Preston DB, D'Augelli AR, Kassab CD, et al.. The relationship of stigma to the sexual risk behavior of rural men who have sex with men. AIDS Educ Prev. 2007;19:218–230.
          27. Berg RC, Ross MW, Weatherburn P, et al.. Structural and environmental factors are associated with internalised homonegativity in men who have sex with men: findings from the European MSM Internet Survey (EMIS) in 38 countries. Soc Sci Med. 2013;78:61–69.
          28. Knox J, Sandfort T, Yi H, et al.. Social vulnerability and HIV testing among South African men who have sex with men. Int J STD AIDS. 2011;22:709–713.
          29. Grov C, Crow T. Attitudes about and HIV risk related to the “most common place” MSM meet their sex partners: comparing men from bathhouses, bars/clubs, and AIDS Educ Prev. 2012;24:102–116.
          30. Binson D, Woods WJ, Pollack L, et al.. Differential HIV risk in bathhouses and public cruising areas. Am J Public Health. 2001;91:1482–1486.
          31. de Wit JB, de Vroome EM, Sandfort TG, et al.. Homosexual encounters in different venues. Int J STD AIDS. 1997;8:130–134.
          32. Grov C, Hirshfield S, Remien RH, et al.. Exploring the venue's role in risky sexual behavior among gay and bisexual men: an event-level analysis from a national online survey in the U.S. Arch Sex Behav. 2013;42:291–302.
          33. Pollock JA, Halkitis PN. Environmental factors in relation to unprotected sexual behavior among gay, bisexual, and other MSM. AIDS Educ Prev. 2009;21:340–355.
          34. Reisner SL, Mimiaga MJ, Skeer M, et al.. Differential HIV risk behavior among men who have sex with men seeking health-related mobile van services at diverse gay-specific venues. AIDS Behav. 2009;13:822–831.
          35. Wilson PA, Cook S, McGaskey J, et al.. Situational predictors of sexual risk episodes among men with HIV who have sex with men. Sex Transm Infect. 2008;84:506–508.
          36. Woods WJ, Binson D. Public health policy and gay bathhouses. J Homosex. 2003;44:1–21.
          37. Woods WJ, Euren J, Pollack LM, et al.. HIV prevention in gay bathhouses and sex clubs across the United States. J Acquir Immune Defic Syndr. 2010;55:S88–S90.
          38. Huebner DM, Binson D, Dilworth SE, et al.. Rapid vs. standard HIV testing in bathhouses: what is gained and lost? AIDS Behav. 2010;14:688–696.
          39. Rosser BRS, West W, Weinmeyer R. Are gay communities dying or just in transition? Results from an international consultation examining possible structural change in gay communities. AIDS Care. 2008;20:588–595.
          40. Burrel ER, Pines HA, Robbie E, et al.. Use of the location-based social networking application GRINDR as a recruitment tool in rectal microbicide development research. AIDS Behav. 2012;6:1816–1820.
          41. Carballo-Dieguez A, Dowsett GW, Ventuneac A, et al.. Cybercartography of popular internet sites used by New York city men who have sex with men interested in bareback sex. AIDS Educ Prev. 2006;18:475–489.
          42. Davis M, Hart G, Bolding G, et al.. Sex and the Internet: gay men, risk reduction and serostatus. Cult Health Sex. 2006;8:161–174.
          43. Grov C, Bamonte A, Fuentes A, et al.. Exploring the internet's role in sexual compulsivity and out of control sexual thoughts/behaviour: a qualitative study of gay and bisexual men in New York City. Cult Health Sex. 2008;10:107–124.
          44. Ostergren JE, Rosser BRS, Horvath KJ. Reasons for non-use of condoms among men who have sex with men: a comparison of receptive and insertive role in sex and online and offline meeting venue. Cult Health Sex. 2011;13:123–140.
          45. Bolding G, Davis M, Hart G, et al.. Gay men who look for sex on the Internet: is there more HIV/STI risk with online partners? AIDS. 2005;19:961–968.
          46. Horvath KJ, Rosser BRS, Remafedi G. Sexual risk taking among young internet-using men who have sex with men. Am J Public Health. 2008;98:1059–1067.
          47. Liau A, Millett G, Marks G. Meta-analytic examination of online sex-seeking and sexual risk behavior among men who have sex with men. Sex Transm Dis. 2006;33:576–584.
          48. Mustanski B, Lyons T, Garcia SC. Internet use and sexual health of young men who have sex with men: A Mixed-Methods Study. Arch Sex Behav. 2011;40:289–300.
          49. Ogilvie GS, Taylor DL, Trussler T, et al.. Seeking sexual partners on the internet—a marker for risky sexual behaviour in men who have sex with men. Can J Public Health. 2008;99:185–188.
          50. Jenness SM, Neaigus A, Hagan H, et al.. Reconsidering the internet as an HIV/STD risk for men who have sex with men. AIDS Behav. 2010;14:1353–1361.
          51. Kakietek J, Sullivan PS, Heffelfinger JD. You've got male: internet use, rural residence, and risky sex in men who have sex with men recruited in 12 U.S. cities. AIDS Educ Prev. 2011;23:118–127.
          52. Mustanski B. Are sexual partners met online associated with HIV/STI risk behaviours? Retrospective and daily diary data in conflict. AIDS Care. 2007;19:822–827.
          53. White JM, Mimiaga MJ, Reisner SL, et al.. HIV sexual risk behavior among black men who meet other men on the internet for sex. J Urban Health. 2013;90:464–481.
          54. Allison S, Bauermeister JA, Bull S, et al.. The intersection of youth, technology, and new media with sexual health: moving the research agenda forward. J Adolesc Health. 2012;51:207–212.
          55. DeHaan S, Kuper LE, Magee JC, et al.. The interplay between online and offline explorations of identity, relationships, and sex: a mixed-methods study with LGBT youth. J Sex Res. 2012;50:421–434.
          56. Guse K, Levine D, Martins S, et al.. Interventions using new digital media to improve adolescent sexual health: a systematic review. J Adolesc Health. 2012;51:535–543.
          57. Chiasson MA, Hirshfield S, Rietmeijer C. HIV prevention and care in the digital age. J Acquir Immune Defic Syndr. 2010;55:S94–S97.
          58. George S, Phillips R, McDavitt B, et al.. The cellular generation and a new risk environment: implications for texting-based sexual health promotion interventions among minority young men who have sex with men. AMIA Annu Symp Proc. 2012;2012;247–256.
          59. Jaganath D, Gill HK, Cohen AC, et al.. Harnessing online peer education (HOPE): integrating C-POL and social media to train peer leaders in HIV prevention. AIDS Care. 2012;24:593–600.
          60. Noar SM, Willoughby JF. eHealth interventions for HIV prevention. AIDS Care. 2012;24:945–952.
          61. Kelley CF, Haaland RE, Patel P, et al.. HIV-1 RNA rectal shedding is reduced in men with low plasma HIV-1 RNA viral loads and is not enhanced by sexually transmitted bacterial infections of the rectum. J Infect Dis. 2011;204:761–767.
          62. Das M, Chu PL, Santos GM, et al.. Decreases in community viral load are accompanied by reductions in new HIV infections in San Francisco. PLoS One. 2010;5:e11068.
          63. Birrell PJ, Gill ON, Delpech VC, et al.. HIV incidence in men who have sex with men in England and Wales 2001–10: a nationwide population study. Lancet Infect Dis. 2013;13:313–318.
          64. Marks G, Crepaz N, Janssen RS. Estimating sexual transmission of HIV from persons aware and unaware that they are infected with the virus in the USA. AIDS. 2006;20:1447–1450.
          65. Vernazza PL, Troiani L, Flepp MJ, et al.. Potent antiretroviral treatment of HIV-infection results in suppression of the seminal shedding of HIV. The Swiss HIV Cohort Study. AIDS, 2000;14:117–121.
          66. Politch JA, Mayer KH, Welles SL, et al.. Highly active antiretroviral therapy does not completely suppress HIV in semen of sexually active HIV-infected men who have sex with men. AIDS. 2012;26:1535–1543.
          67. Grinsztejn B, Ribaudo H, Cohen MS, et al.. Effects of early versus delayed initiation of antiretroviral therapy (ART) on HIV clinical outcomes: results from the HPTN 052 randomized clinical trial (Poster abstract). Paper presented at: IAS; July, 17–20, 2011; Rome, Italy.
          68. When To Start Consortium, Sterne JA, May M, et al.. Timing of initiation of antiretroviral therapy in AIDS-free HIV-1-infected patients: a collaborative analysis of 18 HIV cohort studies. Lancet. 2009;373:1352–1363.
          69. Carballo-Diéguez A, Frasca T, Balan I, et al.. Use of a rapid HIV home test prevents HIV exposure in a high risk sample of men who have sex with men. AIDS Behav. 2012;16:1753–1760.
          70. Wagenaar BH, Christiansen-Lindquist L, Khosropour C, et al.. Willingness of US men who have sex with men (MSM) to participate in couples HIV voluntary counseling and testing (CVCT). PLoS One. 2012;7:e42953.
          71. Baral S, Sifakis F, Cleghorn F, et al.. Elevated risk for HIV infection among men who have sex with men in low- and middle-income countries 2000–2006: a systematic review. PLoS Med. 2007;4:e339.
          72. Burrell E, Mark D, Grant R, et al.. Sexual risk behaviours and HIV-1 prevalence among urban men who have sex with men in Cape Town, South Africa. Sex Health. 2010;7:149–153.
          73. Dahoma M, Johnston LG, Holman A, et al.. HIV and related risk behavior among men who have sex with men in Zanzibar, Tanzania: results of a behavioral surveillance survey. AIDS Behav. 2011;5:186–192.
          74. Lane T, Raymond HF, Dladla S, et al.. High HIV prevalence among men who have sex with men in Soweto, South Africa: results from the Soweto men’s study. AIDS Behav. 2011;15:626–634.
          75. Merrigan M, Azeez A, Afolabi B, et al.. HIV prevalence and risk behaviours among men having sex with men in Nigeria. Sex Transm Infect. 2011;87:65–70.
          76. Price A, Rida W, Mwangome M, et al.. Identifying at-risk populations in Kenya and South Africa: HIV incidence in cohorts of men who report sex with men, sex workers, and youth. J Acquir Immune Defic Syndr. 2012;59:185–193.
          77. Rispel LC, Metcalf CA, Cloete A, et al.. HIV prevalence and risk practices among men who have sex with men in two South African cities. J Acquir Immune Defic Syndr. 2011;57:69–76.
          78. Sanders EJ, Graham SM, Okuku HS, et al.. HIV-1 infection in high risk men who have sex with men in Mombasa, Kenya. AIDS, 2007;21:2513–2520.
          79. Sanders EJ, Okuku HS, Smith AD, et al.. High HIV-1 incidence, correlates of HIV-1 acquisition, and high viral loads following seroconversion among MSM. AIDS, 2013;27:437–446.
          80. Vuylsteke B, Semde G, Sika L, et al.. High prevalence of HIV and sexually transmitted infections among male sex workers in Abidjan, Cote d'Ivoire: need for services tailored to their needs. Sex Transm Infect. 2012;88:288–293.
          81. Baral S, Trapence G, Motimedi F, et al.. HIV prevalence risks for HIV infection, and human rights among men who have sex with men (MSM) in Malawi, Namibia, and Botswana. PLoS One. 2009;4:e4997.
          82. Beyrer C, Trapence G, Motimedi F, et al.. Bisexual concurrency, bisexual partnerships, and HIV among Southern African men who have sex with men (MSM). Sex Transm Infect. 2010;86:323–327.
          83. Wade AS, Kane CT, Diallo PAN, et al.. HIV infection and sexually transmitted infections among men who have sex with men in Senegal. AIDS. 2005;19:2133–2140.
          84. Wade AS, Larmarange J, Diop AK, et al.. Reduction in risk-taking behaviors among MSM in Senegal between 2004 and 2007 and prevalence of HIV and other STIs. ELIHoS Project, ANRS 12139. AIDS Care. 2010;22:409–414.
          85. Baral SD, Poteat T, Strömdahl S, et al.. Worldwide burden of HIV in transgender women: a systematic review and meta-analysis. Lancet Infect Dis. 2012;3099:70315–70318.
          86. Bastos FI, Cáceres C, Galvão J, et al.. AIDS in Latin America: assessing the current status of the epidemic and the ongoing response. Int J Epidemiol. 2008;37:729–737.
          87. Cáceres CF, Aggleton P, Galea JT. Sexual diversity, social inclusion and HIV/AIDS. AIDS. 2008;22(suppl 2)S45–S55.
          88. Goodreau SM, Carnegie NB, Vittinghoff E, et al.. What drives the US and Peruvian HIV epidemics in men who have sex with men (MSM)? PLoS One. 2012;7:e50522.
          89. van Griensven F, de Lind van Wijngaarden JW, Baral S, et al.. The global epidemic of HIV infection among men who have sex with men. Curr Opin HIV AIDS. 2009;4:300–307.
          90. Han X, Xu J, Chu Z, et al.. Screening acute HIV infections among Chinese men who have sex with men from voluntary counseling and testing centers. PLoS One. 2011;6:e28792.
          91. Zhang M, Chu Z, Wang H, et al.. A rapidly increasing incidence of HIV and syphilis among men who have sex with men in a major city of China. AIDS Res Hum Retroviruses. 2011;27:1139–1140.
          92. Thomas B, Mimiaga MJ, Mayer KH, et al.. The influence of stigma on HIV risk behavior among men who have sex with men in Chennai, India. AIDS Care. 2012;24:1401–1406.
          93. Wheeler T, Kiran U, Dallabetta G, et al.. Learning about scale, measurement and community mobilisation: reflections on the implementation of the Avahan HIV/AIDS initiative in India. J Epidemiol Community Health. 2012;66(suppl 2):ii16–ii25.
          94. Beyrer C, Sripaipan T, Tovanabutra S, et al.. High HIV, hepatitis C and sexual risks among drug-using men who have sex with men in northern Thailand. AIDS. 2005;19:1535–1540.
          95. Phillips AE, Molitor J, Boily MC, et al.. Informal confidential voting interviewing in a sexual risk assessment of men who have sex with men (MSM) and transgenders (hijra) in Bangalore, India. Sex Transm Infect. 2013;89:245–250.
          96. McClintock M, Herdt G. Rethinking puberty: the development of sexual attraction. Curr Dir Psychol Sci. 1996;5:178–183.
          97. Almeida J, Johnson RM, Corliss HL, et al.. Emotional distress among LGBT youth: the influence of perceived discrimination based on sexual orientation. J Youth Adolesc. 2009;38:1001–1014.
          98. Dube EM, Savin-Williams RC. Sexual identity development among ethnic sexual-minority male youths. Dev Psychol. 1999;35:1389–1398.
          99. Ramafedi G. Male homosexuality: the adolescent’s perspective. Paediatrics. 1987;79:326–330.
          100. Steinberg L. Risk taking in adolescence: what change and why? Ann N Y Acad Sci. 2004;1021:51–58.
          101. Bekker LG, Glidden D, Hosek S, et al.. Pre-exposure prophylaxis in young men who have sex with men: needs and challenges. Paper presented at: 20th Conference on Retroviruses and Opportunistic Infections; March 3–6, 2013; Atlanta, GA.
          102. Osterberg L, Blashke T. Adherence to medication. N Engl J Med. 2005;353:487–497.
          103. van Rooyen H, McGrath N, Chirowodza A, et al.. Mobile VCT: reaching men and young people in urban and rural South African pilot studies (NIMH project accept, HPTN 043). AIDS Behav. 2012 PMID:23142856 [epub ahead of print].
          104. Coates T, Eshleman S, Chariyalertsak S, et al.. Community-level reductions in estimated HIV incidence: HIV prevention trials network 043, project accept. Paper presented at: 20th Conference on Retroviruses and Opportunistic Infections; March 3–6, 2013; Atlanta, GA.
          105. Anderson PL, Glidden DV, Liu A, et al.. Emtricitabine-tenofovir concentrations and pre-exposure prophylaxis efficacy in men who have sex with men. Sci Transl Med. 2012;4:151ra125.
          106. Mutua G, Sanders E, Mugo P, et al.. Safety and adherence to intermittent pre-exposure prophylaxis (PrEP) for HIV-1 in African men who have sex with men and female sex workers. PLoS One. 2012;7:e33103.
          107. Abdool Karim Q, Abdool Karim SS, Frohlich JA, et al.. Effectiveness and safety of tenofovir gel, an antiretroviral microbicide, for the prevention of HIV infection in women. Science. 2010;329:1168–1174.
          108. Anton PA, Cranston RD, Kashuba A, et al.. RMP-02/MTN-006: a phase 1 rectal safety, acceptability, pharmacokinetic, and pharmacodynamic study of tenofovir 1% gel compared with oral tenofovir disoproxil fumarate. AIDS Res Hum Retroviruses. 2012;28:1412–1421.
          109. McGowan I, Hoesley C, Andrew P, et al.. MTN-007: a phase 1 randomized, doubleblind, placebo-controlled rectal safety and acceptability study of tenofovir 1% gel. Paper presented at: CROI 2012 19th Conference on Retroviruses and Opportunistic Infections; March 5–8, 2012; Washington, DC.
          110. Baral S, Burrell E, Scheibe A, et al.. HIV risk and associations of HIV infection among men who have sex with men in peri-urban Cape Town, South Africa. BMC Public Health. 2011;11:766.
          111. Wirtz AL, Walker DG, Bollinger L, et al.. Modelling the impact of HIV prevention and treatment for men who have sex with men on HIV epidemic trajectories in low- and middle-income countries. Int J STD AIDS. 2013 Mar 19. [Epub ahead of print].
          112. Baral S, Scheibe A, Sullivan P, et al.. Assessing priorities for combination HIV prevention research for men who have sex with men (MSM) in Africa”. AIDS Behav. 2013;17(Suppl 1):60–69.

          men who have sex with men; transgender women; HIV prevention; HIV transmission

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