研究者称：口交不可能传播Hiv

    The 198 participants in this study, nearly all male, were recruited from anonymous testing and counseling sites in San Francisco. All identified themselves as gay or bisexual and reported no anal sex, vaginal sex or injection drug use during the 6 months before the study.


    Participants were screened for HIV infection with a test that can detect an infection contracted within the past 6 months, as well as one that detects the longer-term presence of HIV infection.
    Nearly all reported having had unprotected oral sex with a male partner, and 20% said they had performed oral sex on an HIV-positive partner. Of those, 89% did not use a condom and 40% swallowed ejaculate.
    Yet only one HIV infection was found among all participants, suggesting that the risk of transmission through oral sex was close to zero. According to the researchers, that one infection had not been acquired within the last 6 months and so may not have been attributable to oral sex.