[Question #11307] Potential Exposure - PEP, Test Scope/Timing

15 months ago

Hello,

I recently had a potential high risk exposure. I say "potential" because I was very inebriated and am unsure if any sex (unprotected, oral, or otherwise) occurred, and "high risk" because I (male) recently learned the woman was a CSW of unknown HIV status. No reason for me to suspect either way, just no info.

I sought and obtained HIV PEP and am on a 28-day regimen started 40-hours post-exposure.

1. Was PEP an overreaction, or warranted given my lack of knowledge?

2. What is the soonest point I can have test results that are reliable enough to provide peace of mind? Early detection RNA at 9-10 days after PEP and 4th gen 6 weeks after PEP? Is the 10-day RNA test even worth doing?

3. I had a previous herpes scare due to irritation on my genitals - blood tests and derms confirmed not herpes. Would you recommend blood testing following a high-risk encounter if no symptoms arise?

I suffer from tremendous STI anxiety so am trying to get some clarity as to timeline and next steps.

Edward W. Hook M.D.

15 months ago

Welcome to our Forum and thanks for your questions. I'll be glad to comment. I would classify your exposure as POSSIBLY risky with little risk for acquistion of HIV or other STIs. I say possibly because:

1. You do not know if you were exposed. Even most inebriated persons remember if they had sex

2. Even if you did, the fact is that most CSWs do not have STIs including HIV

3. Even if your partner had untreated HIV and even if you did have sex with her, your risk for getting HIV is less than 1 in 1000 (i.e. there is a more than 99.9% chance you would not be infected following a single encounter.)

If you had asked if you needed PEP, I would have said no although certainly PEP is a personal decision. Thus, in reply to your specific questions:

1. Was PEP an overreaction, or warranted given my lack of knowledge?

In my opinion it was an over reaction although now that you have started it, it might be best to continue.

For follow-up testing the recommended test is a 4th generation, combination HIV antigen/antibody test performed 6 weeks after completion of PEP. For routine HIV diagnosis HIV RNA PCR tests provide answers faster (at 11-12 days after an exposure) but are more expensive. There is little experience and no official recommendations on use of PCR tests for testing after PE although in my opinion, any time after 11 -12 days, a negative PCR test would be strong evidence that you were not infected. If you choose to do this, I would suggest 4th generation testing at 6 weeks out of an abundance of caution

3. I had a previous herpes scare due to irritation on my genitals - blood tests and derms confirmed not herpes. Would you recommend blood testing following a high-risk encounter if no symptoms arise?

NO!! Blood test for herpes are not reliable and confusing. If you do not experience symptoms, please do not do a herpes blood test.

you do not say precisely how long ago this possible encounter occurred. If you are at risk for anything, it is for the most common STIs such as gonorrhea and chlamydia. You can rule these out any time more than 3-4 days after an exposure with a urine test.

I hope this information is helpful. EWH

---

15 months ago

Thank you, Dr. Hook. A few more specific questions on timeline:

1. It is correct that PEP would not delay onset of HSV symptoms, right? So, regardless of HIV PEP use, the normal timeline for HSV symptoms would be potential fever/cold within 2 days of exposure followed by appearance of sores 7-12 days after exposure? Subject to caveats that these symptoms sometimes don’t occur, or take years to surface, etc.?

2. Is it true that even if exposed, PEP would delay being HIV contagious? In other words, if my baseline PCR when I started PEP was negative, I can be confident I am negative until completing PEP, at which point the important questions becomes whether I remain negative (meaning no exposure or PEP worked).

3. Based on the answer to 2 - is protected sex then an essentially no-risk activity (for the counterparty) right now? Or should I just remain abstinent until my 6-week post-PEP test?

Edward W. Hook M.D.

15 months ago

Straight to your follow up questions

1. Taking HIV PEP would have NO influence on the development of symptoms for HSV. If a person is going to develop HSV lesions, this occurs within 10 days of the exposure.

2. The way you pose your question makes it difficult to answer. If your HIVPCR was negative at the time PEP was started and you did not fail PEP, PCRs tests would remain negative and there would be no risk of transmission infection to others. In the very rare event that PEP failed, PCR tests would become positive at about the time of failure. Among untreated persons with positive PCR tests persons would be potentially infectious to sexual partners.

3. If I were in your situation, I would not be concerned about the possibility of having HIV and would not feel the need to abstain from sexual activity. Condom use for sexual activity while taking PEP would only add to my confidence that there is no risk for sexual partners.

I hope this information is helpful to you. EWH

---

14 months ago

Dr. Hook,

Thanks again for replies to date. I’ll use my last follow-up to ask a few questions about PEP:

1. Near the end of my course (day 24 of 28), I missed my daily Truvada and one of my daily Isentress doses. I’m continuing on schedule for the remainder of the 28 days. Is this likely to result in PEP failure?

2. Google says that missing this late in the process is “better” than missing earlier. Is that true, if so why?

3. The course is 28 days but the pill bottles come with 30 days’ worth. Is there any incremental benefit in finishing the 30-day supply or should I toss the extra?

4. Should I get bloodwork done to check for liver issues as a side effect when this is done? I got my PEP from urgent care so haven’t really spoken to my prescriber since.

Edward W. Hook M.D.

14 months ago

Final replies:

1. Missing these doses of your PEP should not reduce its effectiveness.

2. At a cellular level, most of the events leading to HIV acquisition occur soon after exposure, thus having medication present at that time is felt to be more crucial for prevention of infection.

3. I’d toss the remainder

4. I would not bother with follow up blood testing. As long as you are having no problems, you are almost certainly fine.

This completes this thread. I hope the information I have provided has been helpful. I encourage you to move forward following your very low risk encounter and to not worry further.

EWH.

---