Expert: Kristen Brannock, MPH - 1/26/2008

Question
Dear Doctor,
Thank you for your time which you spent for us.
I asked you before about my only episode oral sex case which I was insertive oral sex partner and you told me I wasn't at risk and your second answer was do additional test at 6 month to be more sure.
Today I'd like to ask you about someting regarding test.
MY QUESTION:
Have you ever seen or heard in the history of HIV that -ve HIV test turn to +ve after 4 months? and if you have, Could you explain who are they?
Thank you for your time.

Answer
Yes- because it takes the body a certain amount of time to produce enogh antibodies to be detected by an HIV test. So, if a person tests before their body has produced enough antibodies, they may receive an negative result. And if they test again later, once their body has produced the antibodies, they would receive a positive result. Everyone is different so there is no way to know who will take longer and who will not- that is why there is a window period for HIV testing.