HIV and the Truth About the Bisexual Bridge

Do bisexual men really increase HIV risk in women?

HIV and the Bisexual Bridge
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According to research from the Centers for Disease Control and Prevention (CDC), bisexual men—also referred to as men who have sex with men and women (MSMW)—represent only about two percent of the sexually active male population in the U.S. but remain disproportionately affected by HIV and other sexually transmitted infections (STIs).

The author of the report, Dr. William Jeffries, outlined what he believed to be the behavioral, social and structural factors that place MSMW at increased vulnerability when compared to other groups.

While the HIV prevalence among MSMW is seen to be lower than in gay men—as much as 60 percent lower, according to the report—they remain far higher than their heterosexual male counterparts (10 percent versus 2.2 percent).

Moreover, the rate of STI diagnoses far outweighs that of either group, with 21 percent of the surveyed MSMW reporting an STI in the past 12 months versus 12 percent of gay men and only 2.3 percent for heterosexual men.

Jeffries identified a number of factors that place MSMW at heightened risk while differentiating the infection patterns between sexually active gay and bisexual men. Among the conclusions:

  • Negative social attitudes about bisexuality (biphobia), as well as fear of stigma and public exposure, can prevent MSMW from seeking the HIV care, treatment, and preventive services they may need. One study conducted in 2013 revealed that, of the 1,500 adults surveyed, negative attitudes about bisexuals ran high, with 15 percent asserting that bisexuality was "not a legitimate sexual orientation."
  • These same fears and prejudices can also lead MSMW to elicit, unprotected sexual encounters with other men, often under the influence of alcohol or drugs, with multiple partners, or with commercial sex workers.
  • Because of these issues, MSMW tend to have condomless sex more frequently than other sexually active males. While the desire to prevent pregnancy may prompt some to use condoms with their female partner, some still avoid them for fear that they may suggest infidelity.
  • The lower rate of HIV infection, when compared to gay men, suggests that MSMW may be less likely to practice receptive anal sex. However, with the HIV prevalence being far higher among men than women, the likelihood of transmission via a male partner places MSMW at inherently greater risk that of their heterosexual counterparts.
  • Social isolation and psychological distress may further promote the likelihood of substance abuse and sexual risk-taking in MSMW.

Crossing the Bisexual Bridge

It has long been assumed that bisexual men create a "bridge" of infection between high-risk gay male partners and heterosexual female partners. Some of the current data strongly supports this, although gaps in data collection and methodologies limit the conclusions one can reasonably draw.

One study conducted by the CDC and the New York Department of Health and Hygiene (NYDHH) reported that three out of four of the 648 women diagnosed with HIV in New York City in 2012 had contracted HIV from their MSMW partner. Another Chinese study published in 2012 suggested a five-fold increase risk to women engaging in sex with a bisexual partner.

The NYDHH research excluded any women who were either injecting drug users or engaged in sex with injecting drug users (IDUs).

Of those infected by an MSMW partner, race played an important role, with African American women being 12 times more likely to acquire HIV than white women.

An earlier study by the NYDHH similarly showed that 26 percent of African American males reported sex with both men and women, almost 40 percent more than reported in white males and over 50 percent more than reported in Hispanic males. MSMW with HIV were also more likely to be younger (median age 30), less educated, and from lower-income communities.

On the flip side, white MSMW were more likely to engage in high-risk sexual activities than either African American or Hispanic MSMW, both with their gay male and heterosexual female partners.

Not everyone agrees fully with these findings. A German study conducted in 2010, in which 54,397 bisexual men were interviewed, concluded that, based on behavior and socio-demographics alone, there was "little support for the existence of a substantial ‘bisexual bridge’ in Germany."

Another study from the University of Pittsburgh, criticized by many at the time of its publication, concluded that the MSMW risk to the female partner has been "relatively overstated" in research. The extensive meta-analysis, which reviewed 31 different scientific papers, concluded that of the estimated 1.2 million bisexual men in the United States, 121,800 were HIV-positive—a figure the researchers stated was more or less in line with CDC estimates as to the number of HIV-positive heterosexual men or IDUs in the U.S.

While a number of media outlets were quick to report that the MSMW risk was "no different" to sex with heterosexual males, pundits were quick to point out that an HIV prevalence of 10 percent among MSMW actually placed their females partner at nearly five times greater risk of infection when compared to heterosexual men—mirroring statistics from earlier research.

In the aftermath, the University of Pittsburgh investigators conceded that the confusion caused by their research highlighted the need for "greater national, bisexual-specific data collection and funding for HIV prevalence research in bisexual men" in order to meet the needs of this under-serviced group.


Jeffries, W. "Beyond the Bisexual Bridge." American Journal of Preventive Medicine. September 2014; 47(3):320-329.

Centers for Disease Control and Prevention (CDC). "HIV Infection Among Heterosexuals at Increased Risk — United States, 2010." Morbidity and Mortality Weekly Report (MMWR). March 15, 2013; 62(10):183-188.

Hydzik, A. and McGrath, C. "Considerable gender, racial and sexuality differences in attitudes toward bisexuality." American Public Health Association's 141st Annual Meeting & Exposition; Boston, Massachusetts; November 5, 2013.

Sackoff, J. and Coffee, L. "Are Bisexual Men a Bridge Population for HIV Transmission to Women in NYC?"  New York City Department of Health and Mental Hygiene - HIV Surveillance & Epidemiology Program; New York, New York; published January 3, 2014.

Sekular, T.; Bochow, M; and von Rüden, U. "Are bisexually active men a ‘bridge’ for HIV transmission to the ‘general population’ in Germany? Data from the European Men-Who-Have-Sex-With-Men Internet Survey (EMIS)." Culture, Health & Sexuality: An International Journal for Research, Intervention and Care. July 14, 2014; 16(9):1113-1127

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