Thank you for providing this forum and lending your expertise. I'll go straight to my situation and questions.

I recently had a protected vaginal encounter with a biological female at an Asian spa in Austin, TX. Since I thought she was high risk, I took Biktarvy for two days (from a previous event). I stopped after I realized it would delay my testing window. I have since tested:

23 days PCR

34 days PCR and 4th gen

My dilemma is it has been ingrained in me and from the responses on this forum, that for conclusive results, a 4th gen is needed at 6 weeks/45 days. I have seen a recent shift in your opinion on PCR, so to my questions.

1. Could the two days of Biktarvy have resulted in a false negative with the 23 day PCR?

2. Could you explain how the combination of a PCR and 4th gen make it conclusive after 28 days? 

3. Why the shift in confidence with the PCR?

4. Do I need to take a final 4th gen at 6 weeks or 90 days?

5. What is your recommendation on post PEP testing (complete and interrupted, in my case)

Thank you for your time.

1. Could the two days of Biktarvy have resulted in a false negative with the 23 day PCR?

As you no doubt understand, there are no careful studies of this topic however I would consider your 23 day PCR results reliable.

Most people who develop HIV develop tests well before the 6 week recommendation but to be entirely conclusive, the 6 week recommendation remains the "gold standard".  Persons taking PEP who become infected (very few) typically develop positive tests while taking the meds or soon after but to be safe, most experts continue to recommend follow up testing at 4 - 6 weeks as conclusive.

I hope this information is helpful.  I am confident that you are in the clear.  EWH

1. Would my 2 doses of Biktarvy but not completing the regimen put me in the category of someone "not taking anti-HIV drugs"? I am trying to assess whether I fall into that gold standard of taking a final test at 6 weeks after PEP.

1. Would my 2 doses of Biktarvy but not completing the regimen put me in the category of someone "not taking anti-HIV drugs"? I am trying to assess whether I fall into that gold standard of taking a final test at 6 weeks after PEP.

1. To your comment- "At 28 days or more, over 98% of infected persons will have positive tests.  When combined with a PCR result, as described above, results are conclusive and there are no proven instances in which tests went on to become positive". What is it about the combination of the PCR with the 4th gen that makes it conclusive? I am not clear on this aspect. Don't antibodies have to be present to render conclusive? Is a PCR and 4th gen taken together as conclusive as a 4th gen at post 6 weeks?

Thank you again for your invaluable advice on this forum. Happy holidays!

1. Antibodies DO NOT need to be present for a conclusive test.  My statement is based on scientific studies, reading the medical literature and attendance at scientific conferences.  As explained above  "Our confidence in PCR tests for HIV diagnosis is evolving and with that, our confidence is increasing with experience and better tests  Most experts now believe that a negative PCR test in someone not taking anti-HIV drugs provides entirely conclusive results any time more than 11 days after an exposure.  Previously, just to be sure, follow-up 4th generation testing was suggested.  I know of no instances in which someone with a negative HIV RNA PCR test after 11 days went on to become positive. " 

2.  PEP/Prep on Demand is a relatively recent development in which persons taking a dose of anti-HIV medication before and for a day following a high risk exposure.  It is primarily recommended for transsexual persons and men who have sex with other men. The data from a number of studies suggest it is as effected as PrEP for preventing HIV.  Because it is highly effective, there are few data on how to best follow-up this treatment but the follow-up regimens you list should be effective for proving that infection did not occur.

This complete this thread.  There should be no need to return on this topic.  EWH