[Question #294] Confused about window period

94 months ago
Hello-Thank you for this service, the cost is very minimal to get advice from such renowned experts. I am a women and had unprotected sex with a man of unknown status. I was tested for all STD's including HIV 68 days after the possible exposure.  The HIV test was a rapid blood test.  I had no idea that there was a window period for HIV testing and after i was given my negative result, the technician administering the test stated that it was not conclusive.  I have heard varying time periods for the window period.  I live in a small community and it was very difficult and anxiety provoking to get tested.  I would like to know if you, as an expert of HIV, believe I should be tested again before going through the process? Thank you for all you do.
Edward W. Hook M.D.
94 months ago

Welcome to the Forum.  Before I address your concerns about the window period for your HIV tests, please permit me to make a comment or two about your risk for HIV from the exposure you describe.  Your risk for infection from a single exposure to a heterosexual man in North America or Western Europe is very low.  At the HIGHEST, less than 1% of heterosexual men who do not use IV drugs have HIV. Then, the risk of infection from a single penile-vaginal infection is about 1 infection per 1,000 sex acts.  Thus, statistically, your risk for infection was somewhere in the neighborhood of 1 in 100,000.  Pretty low.

Since then you were tested for STIs including HIV at 68 days following exposure.  Typical, antibody-only rapid HIV tests provide reliable results at 8 weeks following exposure.  Thus, your test results are reliable and prove that you did not get HIV from the exposure that you describe. 

So, why did the technician tell you the results were not reliable.  The answer is that because of the way the studies were performed, plus the fact that counseling by persons performing HIV tests still reflects the performance of older tests that have not been used for over a decade, results in many technicians giving overly conservative advice as to when test results are definitive.  Please do not worry- as I said before, your test results prove that you did not get HIV from the test you describe.

I hope my comments are helpful to you.  EWH