I wish I could tell you that oral sex is definitely safe or definitely unsafe, but I can't. When HIV first hit the gay community, researchers interviewed thousands of men to try to determine what sex acts caused infection. In the early 1980's, virtually every man was having unprotected anal and oral sex. Once safe sex guidelines became well-known, fewer men were becoming infected with HIV. Researchers collected data from thousands of volunteers in order to come to meaningful statistical conclusions about the risk of unprotected oral sex. Unfortunately, some men lied about the kind of sex they were having. Many people think that admitting that we have unprotected anal sex (whether to a friend or healthcare provider) is socially unacceptable; as a result, many men say they only have had unsafe oral sex, when in fact they have also had unprotected anal sex. This has made coming to a meaningful conclusion about the risks of oral sex all the more difficult.
The medical literature is very divided about the risks of unprotected oral sex. The most recent study about the risks of oral sex was presented at the February, 2000 Conferences on Retroviruses and Opportunistic Infections, by Dillon and Hecht. Along with their colleagues, they interviewed 102 men who recently caught HIV. They concluded that eight (7.8 percent) were infected with HIV from unprotected oral sex. But this number might be misleading because only two of the eight men only had oral sex. Four others had protected anal sex but unprotected oral sex while the remaining two had unprotected anal sex with partners who were HIV negative. Thus, there is always the chance that some of those eight men caught HIV from anal sex. (The study was also not very diverse and contained mostly white males.) In addition, it relied on the truthfulness of the information volunteered by the study participants.
Many other studies have shown that oral sex does have a small risk (much less than anal sex) of transmitting HIV. Small risk does not mean no risk! A condom will help protect you.
Does your partner ejaculating into your mouth increase HIV risk? Again, because the numbers of men who catch HIV from unprotected oral sex is so small, it is impossible to further separate the risk into those who take ejaculate in their mouths and those who do not. Intuitively, most doctors agree that a partner ejaculating into your mouth will increase your risk of catching HIV, though there have never been studies to document this. Saliva kills HIV, as do stomach acids. Pre-cum also contains HIV, so just having his penis in your mouth without ejaculation may be more than enough to give you the virus. Should you swallow or not? Again because the numbers are so small we can't determine (for certain) whether swallowing increases or decreases risk. (Yes, it might decrease risk because HIV is killed in your stomach). If you keep his semen in your mouth while you run to the bathroom to demurely spit it out, you are keeping the virus in contact with mucous membranes longer than if you just swallowed.
Other men believe that by not brushing their teeth before going out they protect their gums and decrease their risk of catching HIV from oral sex. Wrong! HIV is so small that it can be seen only with an electron microscope. It only needs a minute hole to get into your body -- the kind we all have in our tonsils and from chronic gum irritation.
All the things we do to protect ourselves from catching HIV though unprotected oral sex actually do little more than make us feel safer.
In conclusion, unprotected oral sex has some risk of transmitting HIV. This risk probably increases with ejaculation. As more men have protected anal sex, the risk of catching HIV from unprotected oral sex will become more significant.
