How do men get AIDS from heterosexual intercourse?

The other AIDS thread got me thinking about the mechanism by which men get AIDs from heterosexual intercourse. Does the virus swim down the urethra? Would ejaculating reducing chances of transmission by forcing out any virus that made its way in?

It’s my understanding that once the little buggers get in your system, even for a split second, they’re IN. Go to phase two.

Not necessarily. It needs a certain viral load for the HIV to establish itself. The body will probably shrug off a few virus particles, as the chance of them finding and hooking up with the proper type of cell is rather small.

But if enough are present, some will find themselves attaching to the right sort of cell, some will manage to attach and inject their nucleic material, and a couple will manage to make more HIV.

So basically, heterosexual intercourse causes vaginal fluid to get on the skin of the penis, and some viral particles in the vaginal fluid absorb into the blood directly through the skin? And then some vaginal fluid usually gets forced into the urethra by the thrusting motion, causing some viral particles to absorb into the bloodstream through the walls of the urethra? Is that an accurate picture of how it happens? Clearly it’s not as straightforward as a bunch of virus-filled fluid being injected into an orifice like it is with male-to-female transmission… which explains the data Hello Again posted here. Fascinating.

Well, there is the fact that a lot of dudes lie when they are asked if they have had homosexual sex or use IV drugs.

Which has what exactly to do with female-to-male transmission?

It has nothing to do with the transmission itself, but could inflate the statistics.

I don’t know that it does, nor how much, but it seems conceivable at least.

Consistent with the study linked by Hello Again, female-to-male transmission appears to be associated with some sort of “blood exposure,” e.g., lesions from herpes or another venereal disease. (Whether always or merely usually is the big open question right now.) That’s one reason the heterosexual transmission rate is higher in less-developed countries. They are less likely to have been treated for the “door opening” disease, simply because they’re poor.

Dr Deth is trying to point out that the percentage of female-to-male transmissions may be lower than reported because some men would not admit to a gay encounter. According the CDC, 7% of male HIV cases were reported as heterosexual (through June 2000). Site: http://www.cdc.gov/hiv/stats/hasr1201/table10.htm

It would be interesting to know scientifically what percent were being truthful but I suppose that is impossible. Has there ever been a documented case of HIV transmission from female to male under laboratory conditions (perhaps using lab animals?)

Right. Or not admit to using IV drugs.

Just anecdotally it’s possible for the shaft of a man’s penis to become severely chafed after multiple sessions of long and vigorous heterosexual intercourse. It’s not out of the question that this chafed area may be raw enough in some cases to be open viral penetration.

Having said this, I have heard the statistic quoted that a man in a western, industrialized society has a greater chance of drowning in his bathub than he does of contracting AIDS through heterosexual intercourse. The overwhelming incidence of western males contacting AIDS is through (receiving) anal sex in some fashion or IV drug use.

Would I be right in thinking this is a statistical thing, where there will still be a few unlucky individuals who contracted the infection from a very small viral load (that just happened to prosper), as well as a few lucky individuals who took a larger viral load and somehow escaped infection?