[Question #8998] Testing Post PEP

37 months ago

Hello doctors sorry to be back again but my local doctors are not very versed on this specific topic.

As mentioned previously I had an exposure (vaginal penetration but no ejaculation) with a presumed heterosexual man and took 30 days of PEP. Threw up or missed a dose once.

I recently took a RNA test at 14 days post completion of PEP. Could this be considered to be reassuring or close to conclusive? Would an additional 4 week ag/ab test be considered conclusive or is it better to wait until 6 weeks post pep?

Thank you and hopefully this can also help anybody else on PEP reading

H. Hunter Handsfield, MD

37 months ago

Welcome back, but having scanned your previous three threads with Dr. Hook (and agreeing with all he said), I don't really understand why you're here. These questions were answered in the previous discussions.

I agree with Dr. Hook's assessment that taking PEP after this exposure was unnecessary; the large majority of HIV experts would not have agreed to prescribe it, if they had the complete story of the exposure. The main effect of doing so has been to prolong your period of uncertainty until you have conclusive test results.

Yes, your negative RNA test at 14 days should be reassuring; it is close to conclusive. But for truly conclusive results, you'll need to wait until having the AgAb test at 4 weeks -- or, per the advice of many experts, 6 weeks after the last dose of PEP.

Let me know if anything isn't clear.

HHH, MD

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37 months ago

Thank you Doctor, I understand the exposure is low risk but as far as I understand even brief penetration is still a risk? That’s why I preferred to take PEP.

Considering my risk was low to begin with, I took PEP (aside from one missed dose), and my negative RNA test results at 14 days, what are my chances of testing negative at 6 weeks with an ag/ab test?

H. Hunter Handsfield, MD

37 months ago

Let's address this in statistical terms. Looking back at your original thread on this topic, I would estimate there's maybe one chance in a thousand your partner had HIV. If you had vaginal sex to completion with such a person, the chance of transmission (if he is HIV infected) is roughly one in a thousand. So even with complete intercourse, your risk of catching HIV was maybe one in a million. Given the uncertain or maybe very brief penetration, the chance of transmission would be at least a hundred fold lower, i.e. one chance in 100,000. So the odds you caught HIV probably are no higher than one chance in 100 million. That is zero for all practical purposes, and it is why you should not have requested or taken PEP. Had you given such a story in my clinic, we would have refused to prescribe PEP no matter how strongly you requested it. Your risk was low enough that you didn't even need HIV testing, let alone PEP.

Now let's factor in that you DID take PEP. That reduced the chance you have HIV by another hundred fold, so the odds you have HIV become one in 10 billion. Now let's estimate a one chance in a hundred that your recent RNA test missed an infection. Now the chance you have HIV calculates at one chance in a trillion. Feel free to do your own calculations to check my math, but you get the idea. This obviously is zero for all practical purposes.

And so the answer is yes: your 6 week test will also be negative.

Please do not ask again whether you might have HIV, or whether you can rely on your test results. The answers to those questions are no and yes, respectively, no matter what other information or concerns you might think you need to ask about. OK? Got it?

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36 months ago

Thank you doctor but again considering this man was trying to take advantage the entire time, I’d like for the assessment to factor in the risk of brief penetration that did occur (not just maybe or uncertain) as well as the missed dose of PEP that I threw up.

I only ask for clarification because I notice in your assessment you consider the incident as only maybe having occurred and no mention of how the missed dose of PEP may affect it.

Would these two factors considerably change the odds or chance of a negative 6 week test?

And no worries if I receive a negative result on the 6 week test I will gladly accept it.

H. Hunter Handsfield, MD

36 months ago

I understood all this from the start and carefully took into account these factors and your entire situation.

That concludes this thread. Repeated questions on the same topics are not permitted, especially when obviously anxiety driven. ASHA is not keen on collecting fees for questions with unchanged and obvious answers; repeated responses to anxiety driven questions tend to enhance and prolong such anxiety rather than relieving it; and such questions have little educational value for other users, one of the forum's main purposes. Repeated questions on the same topic may be deleted without reply, and without refund of the posting fee. And you can be certain the answers would not change, no matter what additional "what if" or "could I be the exception" sorts of thoughts might come to mind -- so please do not be tempted.

I do hope the discussions have helped you to relax and stop worrying while you await your final test result. You can be sure it will also be negative. Best wishes and stay safe.

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