I had previously requested more information (#12170) regarding the ability to trust HIV testing results after the window period. I keep seeing references to PrEP potentially delaying accurate results/seroconversion and I just wanted to ask the following: considering I am taking PrEP daily, can I trust the accuracy of HIV testing (a combination of Ab/p24 Ag, RNA, Real Time PCR, and antibody testing via finger prick and oral swab) after an eight-month period? My last test was two weeks ago (antigen/antibody) via a blood draw, and it returned as NEGATIVE. Is there the potential that my PrEP usage is still delaying seroconversion and, if so, at what point can I be confident in my results? 

I'm not sure what you mean by "after an eight-month period". Do you mean 8 months continuing to take PrEP? Or have 8 months passed since stopping PrEP? If the latter, your test results conclusively prove you do not have HIV, assuming no sexual exposures during that time.

I hope these comments are helpful. Let me know if anything isn't clear.

HHH, MD

My apologies for not being very clear - my previous question (#12170) had more context: in early April, the HIV test that I complete for my PrEP prescription came back as positive. I was told to immediately stop PrEP and to begin taking Dovato. I was also told come back for a “confirmation” test the very next day. This confirmation test (both “HIV Ab/p24 Ag screen” and "RNA, Real Time PCR”) came back as negative. I then stopped Dovato, and did not take any medication for a period of approximately two to three weeks. I was then re-tested (“HIV Ab/p24 Ag screen” and "RNA, Real Time PCR” and a comprehensive blood panel), and all tests came back as negative for HIV. At this time, I restarted my daily use of PrEP as my doctor stated he was "confident" that my vial had gotten mislabeled (he said that it had happened a few times before at their clinic). I have had repeated rapid tests (finger prick and oral) and laboratory tests (both “HIV Ab/p24 Ag screen” and "RNA, Real Time PCR”) performed nearly monthly since then and all have come back negative. I tested via lab draw ("Ab/p24 Ag screen") as recently as December 2nd, and this too returned as negative.

Since the doctor approved getting back on PrEP, I have been consistent with my daily usage. My concern, provided I've had no exposure since April, is whether or not I can have confidence in this most recent test as I do not know if PrEP could potentially still be delaying a positive result. Thank you!