Knowledge of partner risk and secondary transmission of HIV

BACKGROUND: The number and proportion of people living longer with HIV and the proportion of people infected heterosexually have increased. We measured the frequency with which people with heterosexually acquired AIDS knew their partners' risk behaviors, the extent of secondary heterosexual transmission of HIV, and characterized people at risk for secondary heterosexual transmission. METHODS: For each of five sites (Alabama, California, Florida, New Jersey, and Texas) and for New York City, a sample of adults with AIDS was interviewed. Primary heterosexual transmission was contact with a partner who had a known risk factor for HIV infection. Secondary transmission was contact with an HIV-positive partner not known to have a risk for HIV. RESULTS: Among men, 35% knew that a sexual partner was HIV infected, 56% of women knew that a sexual partner was HIV infected. Among women, 12% knew that a partner was bisexual. Overall, 79% (460 of 581) reported a partner with a primary risk for HIV; among men, 236 of 293 (81%), and among women, 224 of 288 (78%) reported a partner with a primary risk. People categorized with secondary transmission were significantly more likely to be black and never married. People categorized with secondary transmission were more frequently women (53%), had less than a high school education (48%), and a history of drug use (52%). Men categorized with secondary transmission of HIV had a mean of 22 heterosexual partners; women had a mean of 16 partners. CONCLUSIONS: We found that many heterosexuals with AIDS did not know their sexual partners' risk for HIV, and that secondary heterosexual transmission probably results in a small proportion of all AIDS cases in the U.S.