The extent of bisexual behaviour in HIV-infected men and implications for transmission to their female sex partners.

Heterosexual transmission of HIV is a growing problem for women, but many women do not know how their partners acquired HIV. We described a group of HIV-infected men and women, and focused on: (1) sexual identity and bisexual behaviour in men, and (2) the proportion of women who acknowledged having a bisexual male partner. This study examined HIV-infected persons who participated in a cross-sectional interview project from January 1995 through July 2000; 5,156 men who have sex with men (MSM), and 3,139 women. The proportion of MSM who reported having sex with women (MSM/MSW) varied by race: 34% of black MSM, 26% of Hispanic MSM, and 13% of white MSM. While 14% of white women acknowledged having a bisexual partner, only 6% of black and 6% of Hispanic women reported having a bisexual partner. Most behaviourally bisexual men identified as either bisexual (59%) or homosexual (26%). Among MSM/MSW, 30% had more female partners than male partners, while only 10% had more male partners than female partners. These data suggest that bisexual activity is relatively common among black and Hispanic HIV-infected MSM, few identify as heterosexual, and their female partners may not know of their bisexual activity.