Re: Blow job (oral sex) can transmit AIDS
actaully, lonestar, I believe that it's possible even if you have bleeding gums and he's got a lot of pre-cum.
Probable? no... common? no... but possible.
precum has about the same viral load as saliva. semen, on the other hand, is full of CD4+ cells (macrophages) that are reserviors of infection. Thus, seminal fluid has a higher viral load even then blood in infected individuals.
Saliva is loaded with immunoglobulin A (IgA), an inspecific immunoglobulin which globs on to invading pathogens, inhibiting their ability to infect. This makes sense, as the mouth is one of the body's principle portals. Salivary immunoglobulin is the first step in sanitizing food.
Also, saliva has the enzyme amylase, which is the first step in digesting carbohydrates. As many pathogens, including HIV, are coated with 'glycoproteins' (protiens complexed to sugars/carbohydrate, such as the infamous GP120), digestion of these carbohydrates will also inhibit the pathogen's ability to infect.
Unfortunately, the anus is not, functionally speaking, a portal. It is an exit. Thus, it does not enjoy the salivary immunosurvaillence as the does the mouth.
The mechanism for infection by oral sex that does not culminate in climax is there, just as it is for kissing. So it could happen. While swallowing raises your risk exponentially, it is still nowhere near as high as for unprotected anal sex.
If I've said once, I've said it 1000 times: know who you blow
