anxious about a possible past exposure

[OCguy233]

Dear Dr. - recently I have become worried (and obsessed) with a 1 time encounter with a woman (early 40's - I'm later 40's) I met and developed a relationship with over the internet - Early Dec. 2010 - we had unprotected vaginal and mutual oral sex (2 times in one evening - thats it) - I offered to use a condom but she said she was clean so no worries - I understand that the likelyhood of her being positive is low (she was not a prostitute but did inform me that she had 3-4 partners after she split with her husband before me) - say 1% chance? - even if she was positive my chances are 1:1000 to 1:2000 - so combined with her likelyhood of being infected - 1:100000 to 1:200000, correct? - this was 10 months ago - I've never experienced any of the symptoms described (I had what I am convinced was a norovirus - cramps, headache, violent vomiting at the end of Feb. 2011 - 2.5 months after that exposure) - would you as my doctor send me to get tested?

lastly for interest - you or your college states the HIV virus is hard to transmit - harder from a female to male - is this because a significant amount of vaginal fluid with a significant viral load has to be worked deep into the male urethra (the membranous or prostatic urethra) or just contact with the penile urethra?

sorry for being long winded

[Edward W Hook, MD]

Welcome to the Forum.  Before I even deal with your specific case and situation, the answer to your question about would I recommend testing is yes.  Why?  Because by your own admission, you are worried about it and testing is a powerful/definitive way to prove that you are not infected, as is very, very likely to be the risk. If you are truly anxious about whether or not you got HIV from this encounter, for me to provide statistics will not keep you from anxiously worrying that you will be "the one" out of ------ who gets/got infected. The tests are very reliable.  I suggest you get one.  

As for your specific situation, your calculations are correct and, if anything, on the conservative side of things.  

Finally, about male to female transmission, important factors are that anatomy makes female exposure longer lasting and more intense than male exposure.  As you point out, the male urethra is a smaller "target" than the female genital tract. Further, when the male withdraws from a partner, his penis dries off an the virus dies. In contract, genital secretions remain warm and present in the female genital tract for a longer period following sex and "departure" of the male penis.

I hope these comments are helpful. EWH

[OCguy233]

I'm starting to come to that realization - thank you for your time

[Edward W Hook, MD]

Your concrns and anxiety are working overtime.  I will provide only a brief comment on the two statements you make above.  Please understnad that in science, our comments are measured because, for a number of statistically complex reasons, one can never say never.

First comment. HIV can be transmitted in the course of heterosexual intercourse to a circumcised man without the presence of a co-existant STD or abrasion however it is not common and the factors you mention increase the risk for transmission.

The symptoms of early HIV have been described as long after exposure as 4 weeks although most occur 2-3 weeks following exposure.

It is time for you to stop worrying and put this behind you. EWH

[OCguy233]

Thanks for your reply - just wondering whether you would provide me with more information based on your experience - it is my understanding through reading many of your answers on this form that HIV is relatively difficulty to transfer between individuals - there are different risks for different situations but based on one of your previous comments - for transfer of HIV from a female to male (circumcised) during unprotected vaginal sex - the much smaller target urethra mucus membrane must be either traumatized through vigorous friction or compromised through an STD (that convey soreness at the tip of the penis which would suggest a more transfer receptive urethral mucus membrane).

lastly - my understanding is that most people (70%?) who contract HIV suffer symptoms such as fever accompanied by a rash and sever sore throat no sooner that 7 to 10 days after exposure and never after 3 weeks - is this accurate -

thanks again for all your advice and knowledge