[Question #8279] Prep and Window Period HIV

46 months ago

5 weeks ago I had sex with another man I was the receptive partner and I’m pretty sure he wore a condom but my anxiety has me questioning myself and now I feel that I need a negative test result before I can move on with my life.

I did a 4th generation test after 4 weeks and 5 days which was negative. I want to accept this and move on.

However, I saw online that taking Prep can delay the window period. During the window period I took a small amount of Prep for the first time, a total of 4 pills.

6 days after the encounter I took a double dose of Prep (2 pills) and 25 days after the encounter I took another double dose (2 pills).

This might sound a bit strange but I was attempting Prep for the first time - ‘on demand’ - both times I ended up just ended up feeling very sick and not having sex and so gave up.

Would taking these 4 Prep pills in the weeks after the sexual encounter impact on my HIV test result? Making it invalid. Or can I believe the result and move on.

H. Hunter Handsfield, MD

46 months ago

Greetings. Welcome to the forum.

As you might have guessed, there are no data that directly address this situation. However, we know that PEP more than 72 hours after exposure is ineffective in preventing HIV. (PrEP drugs of course are similar or the same.) So I am confident that your 4 PrEP pills a week after exposure could not have prevented establishment of HIV if you had been exposed, and the immune response to the virus would have started. Therefore, I also doubt very much that it would significantly delay a positve result with an antigen-antibody (AgAb, 4th generation) blood test result, and I would consider your negative AgAb result at 4+ weeks to be >95% reliable, and another negative at 6 weeks probably would be conclusive (i.e. no delay in conclusive result). However, because I cannot guarantee there might not be a modest delay, I think it would be wise for you to have another test 3 months after the anal sex event. If you do so, stay relaxed as you wait -- almost certainly it will remain negative.

Alternatively, if you are in touch with your partner from 5 weeks ago and able to contact him, consider asking his HIV status; or perhaps being retested now. If negative -- or positive but on treatment with undetectable viral load -- you will know you were not at risk and could forego any further testing.

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

HHH, MD

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46 months ago

Oh dear, I never imagined that in taking Prep I would make my life more stressful.

I messaged the man from 5 weeks ago. He told me we definitely did use a condom and that he is clean in terms of STDs. He also did not ejaculate if that helps... I did leave the encounter pretty certain of condom use. But I let over analysis and anxiety take ahold.

Also it was 2 tables 1 week after sex. Then 2 tables after 25 days after sex. Not sure if that makes any difference.

I probably should just move on but I’m 24 and have only recently accepted my sexuality so am full of guilt and regret but mostly I have an unhealthy obsession with HIV which have taken over my life.

…………..

The knowledge that Prep can cause a delay has made me concerned about a previous encounter.

Could I please ask your advice on the following:

3 and 1/2 months ago on the 15th of June I had a sexual encounter with a man. I was the insertive partner and I used a condom. I did finger the man and several minutes later finger myself. I wanted to get tested after this.

However, exactly 3 weeks later I took Prep on demand 2-1-1.

(As this is a long gap would it still cause a delay?)

Over then next 3 months I took prep on demand 2-1-1 about 4 times. With about 2 weeks or so gap in between.

I tested negative for HIV with a 4th gen test at 4 weeks, 8 weeks and 11 weeks after this exposure.

I know this was likely a low risk event but it would offer me some peace of mind to know that the test results were accurate? Or does my use of prep mean they don’t mean much?

As u might have already noticed, I have an anxiety problem and won’t be engaging in casual sex again. Thank you so much for your patience.

H. Hunter Handsfield, MD

46 months ago

Your tests at those intervals are reliable, especially the last one at 11 weeks. And if you used a condom (I hope!), there was no significant risk from the event anyway.

I suggest you be careful about making unrealistic promises to yourself. Pledges to not engage in sex (or to always follow a diet, or to stop smoking, or to get in shape and exercise) usually are difficult to maintain. Assuming you continue to feel sexual needs, a smarter approach is to a) always speak with prospective partners about mutual HIV and STI status before starting (avoiding those who are infected and not on effective treatment or who don't know); b) use condoms consistently for anal sex (less important for oral), and c) get on PEP or on-demand PrEP and use it consistently and properly. (I question whether feeling sick after one use was really due to the drug -- although if it happens consistently, speak with a knowledgeable doctor about trying a different regimen.)

Finally, if you pursue the safe sex that you have been and intend, you really should not be getting HIV tested after every exposure. A far smarter approach is to trust in the safe sex measures I just outlined, and then plan on regular testing, e.g. every 3-12 months, depending on sexual frequency. But do your best to stop obsessing about individual exposures. In this spirit, the first event you describe here was entirely safe as well. It really doesn't require testing at all. I should have emphasized that in my original reply.

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H. Hunter Handsfield, MD

46 months ago

And by the way, I asked Dr. Hook to take a look at this thread -- so you get two for the price of one! First and perhaps most important, he is more certain than I was that the brief PrEP drugs you took would not delay positive results of the AgAb tests, so you could have a final conclusive result 6 weeks after the sexual contact you are concerned about -- i.e. no need to test at 3 months. On reconsideration, I agree with that revised advice. Second, he also would suggest that you get on a proper, physician-guided PrEP program, so now you have that advice from both of us. Whether continuous PrEP or on-demand should depend on the frequency with which you have potentially unsafe sexual contacts. Most likely on-demand would be best. But once you do it, stick with the program!---

46 months ago

Thank you for your reply. Your responses have been incredibly helpful. This will be my last follow up questions to you. Thank you for your patience.

I will take what you have said on board and try and learn from this, I definitely agree that if I am to use Prep I must commit to it.

Can I just confirm that re. the sexual encounter on the 15th of June despite my sporadic use of Prep in the 3 months following the encounter the negative test result I received after 11 weeks would be conclusive and account for any delay ?

(And yes I did use a condom, the mutual fingering and possible share of fluids was my concern)

….

Re: The most recent encounter.

Thank you for conferring with Dr Hook and for offering that reassurance. Im afraid I made a slight error and believe I took 3 Prep pills 1 week after sex. Then 2 pills 25 days after sex.

I hope the extra pill isn’t significant?

I will try and trust that a condom was used and trust the negative result at 4.5 weeks. Partly as the NHS won’t let me do any more tests … (understandable). If I can’t get a grip I’ll pay privately at 6 weeks.

46 months ago

Hello again, after another sleepless night I will get tested after 6 weeks. Would the extra prep pill I mentioned influence the test being conclusive at 6 weeks?

H. Hunter Handsfield, MD

46 months ago

"Can I just confirm...?" Yes, that is my and Dr. Hook's joint opinion.

Next encounter: Of course one more pill makes no difference. And asking a second time won't ever increase the speed of a forum reply. We don't moderate the forum 24/7, and we try to respond to follow-up questions/comments within 24 hours.

But I have to wonder why you keep taking the meds a week after exposure. If you do so because you anticipate a new exposure in the next day or two (which doesn't happen), that would be appropriate use of PrEP. But if you're doing it because you become nervous about a past exposure, just don't. It won't work! As implied above, I have the impression you're sort of winging it. Please establish a firm relationship with an HIV/AIDS or infectious diseases expert about PrEP then follow the program s/he prescribes.

It also seems apparent you could use professional counseling about your recent understanding of your sexual inclincations. Plenty of resources are available in most communities. I suggest it from comopassion, not criticism.

That concludes this thread. I hope the discussion has been helpful. Note that repeated questions on the same topic are discouraged (and if repeated, are rejected): please no more questions about these exposures and your use of PrEP. Best wishes and stay safe.

HHH, MD

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