Saliva is not a known vector for HIV transmission. Indeed the latest research I have read suggests that saliva actually kills HIV. It is extremely unlikely that you will ever contract HIV through the exchange of saliva alone.
What is possible, though still rare, is that you and a HIV Poz partner may have bleeding gums or micro-abrasions in your mouth at the same time, therefore providing a direct blood vector for the virus. This is why it is vital that you not brush/floss your teeth for a few hours prior to and after sex with a non-monogmous partner- brushing can leave you susceptable to infection.
However this type of vector has been extremely difficult to pin down. I particpated in a study of hundreds of gay/bi men in SF who were sexually active, but only in oral copulation. There was no evidence of oral sex transmissions, and there was anectdotal evidence that saliva acted in its natural capacity to inhibit both viral and bacterial infections.
HIV is actually fairly hard to contract without a direct blood to blood vector, such as a shared needle, or a damaged anal lining. Vaginal cell walls are several times thicker than anal cell walls and therefore provide far more protection.
Condoms are extremely effective in preventing vaginal HIV transmissions. especially when the vagina is well lubricated and healthy. Excessive douching can make the situation much worse- much like brushing- it damages the protective cell walls.
Finally, non-oxynol-9 a common spermicidal lubricant is a serious danger to anyone practicing anal sex, it destroys the cell wall, which in the human rectum in merely one cell thick. It contributes risk to vaginal sex as well, at least in terms of disease transmission. It is better to use condoms without it, unless you are confident that you and your partner are HIV negative, and your primary concern is birth control.
If you remain concerned about salival transmissions, rinsing with a solution of diluted hydrogen peroxide can easily kill any HIV that may remain in your mouth, though the mouth and digestive tracts are not environments where this virus is likely to thrive.
This is way off topic, but I feel compelled to post it anyway as this is an issue on which most gay/bi men have a certain obsession- considering the friends I have lost to HIV even in the past year.
Back to your regularly scheduled nightmares.
[ This Message was edited by: James on 2002-10-16 07:32 ]