Exposure Risk

[Olandus]

Hello Dr.,

Let me begin by thanking you for the service that you are providing. I think it is both convenient and generally excellent advice.  This is my first post, so here goes.  I had unprotected vaginal sex with a female on 9/5 of this year.  I went to Planned Parenthood to have the rapid blood test on 10/16 of this year, which is essentially right at the 6 week mark that I have heard you mention before in similar posts.  That test came back negative.  I have been pretty paranoid, with all this, in large part because the female that I had this exposure with was not the female I am currently dating.  Guilt and paranoia, as it were, are my punishment.  Furthering my anxiety is that I have had slightly swollen/tender lymph nodes just below my ear near my jaw-line, and my throat has been feeling a somewhat funny.  My question is, should I go to get another test performed or can I/should I confident that the last test performed was pretty conclusive?

Thank you and best regards.

[Edward W Hook, MD]

Glad to help.  EWH

[Olandus]

Thank you Dr. Hook.  I greatly appreciate your advice.  I won't bother you with a follow-up question.  Thank you once again.  

[Edward W Hook, MD]

Welcome to our Forum.  I’ll try to help but should first point out that ultimately the course of action in terms of re-testing is one that you will need to decide upon.  I hope the facts I am about to provide will assist you in doing so.

The risk of a single vaginal sexual encounter with a heterosexual women is quite low, even before testing.  Less than 1 in 1000 American women have HIV and that average figure includes women who use IV drugs and therefore have higher than average rates of infection. Furthermore, HIV is transmitted only about once in every 1000-2000 acts of intercourse.  Thus, mathematically, the risk from a single encounter of the sort you describe is less than 1 in a million.  Your risk is lower still since you were tested at about 6 weeks when over 95% of infections would be detectable with a standard blood test for HIV, antibodies. With this knowledge your risk is now considerable less than 1 in 10 million.  For me that would be enough to reassure me and to not seek further testing.  If you wish to be completely sure, you could have another test at 8 weeks when all persons with recent infection would be detectable.  I personally do not see the need but, as I said, this is of course up to you. EWH