window period - is this legit?

Dr's - The following post was put on medehelp.org.  I think the community here would be very interested in your take on this information as it would answer a lot of questions.  This is not related to my negative tests.  If people are putting this kind of information out there I think it is wise to have a Dr. comment on it.  Here is the information and also the link to the full post (http://www.medhelp.org/posts/show/20542):

"For all those that don't understand the variance in Window Period advice;

The 4 factors to calculate your level of HIV risk;

1) The likelihood of a sexual partner having HIV
   Heteroexual encounters this would range from
   1/100 to 5/100
   Homosexual encounters this would range from
   1/100 to 15/100
   Known HIV+ partners the variable is
   1/1

2) The likelihood that a single unprotected act results in  
   infection
   Vaginal (Male)
   1/2000
   Vaginal (Female)
   1/1000
   Anal (receptive M/F)
   1/200
   Anal (Top M/F)
   1/1500
   Male Oral Sex (Giving)
   1/10000
   Everything Else
   0

3) The chance an HIV antibody test fails to pick up an  
   infection at a given post-exposure time point
   3 Week -ve
   1/2
   6 Week -ve
   1/20
   12 Week -ve
   1/200
   24 Week -ve
   1/1000

Calculate your risk; take each of these factors and multiply them together;

A male having unprotected, vaginal sex, once, with a female from a low risk group with a 6 week -ve test has the following risk profile;

HIV+ partner     Vaginal Sex    6 Week -ve
1/100         *  1/2000       * 1/20        = 1/4,000,000 "

If this information is accurate this would answer a lot of questions.

[H. Hunter Handsfield, M.D.]

I agree these figures "answer a lot of questions".  That is why Dr. Hook and I have cited them many times in our replies on this forum.  I also have cited the CDC research on which they are based, published in the journal Sexually Transmitted Diseases, but it bears repeating for those who know how to access the medical literature:  Varghese B, et al. Sex Transm Dis 2002;29:38-43.

Two caveats about these figures.  First, in some instances they are very rough; they should be viewed as general ballpark estimates, not hard and fast numbers.  Second, they are average figures, and there are many circumstances when the transmission risk is substantially higher or lower.  The data do not take account of such things as presence or absence of other STDs in one partner or the other, circumcision status, viral load in the infected person and whether or not s/he is on antiretroviral drugs, and other factors.

HHH, MD

[NeverAgain624]

thank you so much for answering so quickly!

[NeverAgain624]

Just our of curiosity what impact does circumcision have on transmission of hiv?  For the record I am circumcised.

[H. Hunter Handsfield, M.D.]

Uncircumcised men have roughly double the risk of HIV, if exposed, compared to circumcised men.

While it was fine to post the data you did, it isn't right to have more than one contemporaneous thread on one's personal situation, risks, etc.  Dr. Hook has reassured you that you don't have HIV and were not at risk. I won't have any further comment on it.