Vanguard findings differ from American study on oral sex and HIV

The risk of HIV transmission through oral sex has been hotly debated recently, both in the mainstream media and on the internet. Earlier this year an American study suggested that oral sex is riskier than previously thought. Data from the Vanguard Project differ from these findings.

A San Francisco study presented at the seventh annual Conference on Retroviruses and Opportunistic Infections suggested that eight percent of new HIV infections among gay men may be attributable to oral sex:

Study Finds AIDS Virus Passed By Oral Sex (Feb. 1, 2000)
"A study presented at a meeting of AIDS researchers found nearly eight percent of recently infected men in the San Francisco area were infected through oral sex...[The researchers] surveyed 102 gay and bisexual men recently infected with HIV and found oral sex was the only risky behavior that eight of the men had engaged in."

This generated controversy in the media, in AIDS service organizations and on the internet, and Vanguard participants were asking for our perspective on the issue.

The Vanguard Project has collected HIV test results and baseline questionnaires on over 850 gay and bisexual men, some of whom we have been following for nearly five years. If HIV were being commonly spread through oral sex, by now we would have seen unexplained cases of HIV transmission within the cohort.

Everyone who has become HIV-positive while in the Vanguard study reported known high-risk behaviours (i.e. unprotected anal sex and/or sharing needles) prior to infection. We do not have a single unexplained case.

Of 790 HIV-negative participants, 725 (91.8%) engaged in receptive oral sex in the previous year; 695 of them (95.9% or 88% of the total) did so without condoms.

Unprotected oral sex is evidently a very common activity among gay and bisexual men, and it does not appear to be transmitting HIV in our cohort.

If you have any questions or comments on this issue, please don't hesitate to contact Vanguard coordinator Steve Martindale or Vanguard nurse Mary Lou Miller.