a few questions on HIV/STDs

Dear Doctor:

I will ask questions in bullet point fashion to make it easier to answer.  Short background: about 25 days ago, I had sex with a sex worker for one minute. But 30 seconds of the sex was unprotected, because the condom tore.  Let

[H. Hunter Handsfield, M.D.]

Lots of nuance in those questions; I'm going to answer each one quite briefly.  For further information, look at numerous other threads; you can search for "HIV transmission risk", for example.

1) Circumcision increases the risk.  But when the risk is too low to even measure, a 2-fold or even 10-fold increased risk still leaves a miniscule risk.  (10 times almost zero = almost zero).

2) Mostly ARS symptoms will all begin in a few days, not spread out over 2-3 weeks.  Your symptoms don't sound particularly like ARS.

3) The lymphadenopathy (lymph node enlargement) due to ARS is all over the body (neck, underarms, groin), not just a spotty little bump here and there.

4) There are no data to answer your question directly.  However, I doubt that the amount of sexual lubricating fluid present has no relationship to risk of transmitting HIV or other STDs.

5) Different diseases are not transmitted with the same efficiency.  To give a non-STD example, the diarrheal disease shigellosis (bacterial dystentery) can be induced in human volunteers by feeding them as few as 50 shigella bacteria; but another diarrheal disease, salmonellosis, requires at least 50,000 to a million samonella bacteria to cause infection.  HIV transmission (average 1 transmission per 500-1000 episodes of vaginal intercourse) is very much lower than, say, gonorrhea, where the risk is 20-50% (1 in 2 to 1 in 5).  The biological reasons for such differences are only partly understood, and in any case are too complex to go into detail here.

6) If having a negative HIV test result will reassure you more than my words, by all means do it.  But your PCP is right about the relative risks.

Good luck--  HHH, MD