Precum and Heterosexual Sex?

Hi Doctors, thanks in advance for your time. I have a few questions I was hoping you could help me out with? I'm about to go get my second HIV test and needed some information to chew on, as far as how "at risk" I may be.

1. What "decides" how dangerous precum is during vaginal sex? Is it the amount of precum, viral load? A person's immune system? I understand that HIV can be present in precum, but is it typically enough to infect someone?

2. When I was tested last December for HIV, the nurse assured me that the test wouldn't "mean" anything until 6 months after exposure. Was she just being conservative? Or are there blood tests that somehow don't pick up on HIV until 6 months after the fact?

3. My situation: I was very sexually active with a much older man (heterosexual, no injection drugs, but uncircumcised and many, many sexual partners) for a year. We were always very careful and safe, but eventually fell into the trap that (I think) many couples do, where after a certain amount of time and trust we deemed it "ok" to have unprotected vaginal sex. The first encounter was in september, and he did not finish inside me. It didn't last long. In late november, we had unprotected sex twice, and again he "pulled out." Two weeks later, I tested negative for HIV and other STDs. This was two-three weeks after the last possible exposure, and 3 months after the first. I understand that I can't know anything until I go in for another test, which I intend to do, but I was hoping to get an idea on where you think I stand. Should I be as nervous and worried as I am? Would you be expect/be surprised if I tested positive?

4. If a person is infected with HIV and doesn't know it, how long before serious health problems occur, and the person is forced to find out? If a person goes, say, 15 years with HIV and never treats it, would that mean that that person's viral load is extremely high?

Thank you thank you thank you for all your help and information.

[Edward W Hook, MD]

Your questions are important considerations related to evaluating one's risk for HIV.  Getting straight to them:

1.  Pre-ejaculatory fluid is genital secretions and contains HIV although perhaps not as much ounce for ounce as ejaculate.  The most important determinantof virus concetration in any sort of genital secretion is what the amount of HIV virus is that is present in the person's own blood. This amount can, in turn be increased if other STDs are present in the person with HIV.  One virus is enough to infect a person with HIV but getting infected by an HIV virus relates to how much virus is present in the exposure.  After that, it's a numbers game.

2.  The nurse was being overly conservative.  Most experts feel that after 12 weeks (3 months) once can be nearly 100% confident that they are negative.  The reason I say "nearly 100%" because in all science there are "exceptions to the rule" because of the tremendous variability of humans and disease.  Neither of us on this forum have seem a person seroconvert more than 12 weeks after exposure in taking care of person with and at risk for HIV since the beginning of the epidemic.

3.  At 4 weeks after an exposure 85-90% of persons who are going to be infected will have positive blood tests.  If this is an ongoing relationship, have you asked him about his HIV status?  If not, or even if you have, why not ask him to be tested.  If you are both negative, you are safe as long as neither of you has other partners.  If either of you has other partners, safe sex (condoms) is in order.  

4.  On average, without testing it takes as long as 10 years for a person with unsuspected HIV to get tot he stage where they start to get HIV-related illnesses.

Hope this helps.  EWH

[lmiadb]

Thank you so much for all the information. Just to clarify, because I am a bundle of nerves, the relationship abruptly ended in december. So I had unprotected vaginal sex three times with a risky person of unknown HIV status, who never finished inside me. Would you consider my risk to be high? Thank you so much.

[Edward W Hook, MD]

Not enough information to know.  low to moderate I think.  EWH