Question
Is PEP effective if taken 48 hours after exposure?
2 July 2021. Related: All topics, PEP/PEPSE.
I paid for sex with a woman but the condom tore and I only realised after I was done. There is a high chance that she was HIV positive. I started PEP after 48 hours.
I got a PCR test done 17 days after exposure. It had a less than 20/ml (undetectable) result.
Now between 14 and 35 days after exposure I have had signs of thrush, mild red rash on my face and a couple elsewhere. But no fever or swollen lymph glands.
Can the rash and thrush be because of utter stress and obsession?
My doctor says that the PCR can be relied upon and that I am negative.
Can the PEP have reduced the viral load to less than 20/ml as I took it for 15 days before the PCR test?
Please give your expert advice. I am very anxious. Thank you.
Answer
Thank you for your question.
The risk of HIV from one broken condom is very low. If your partner had an undetectable viral load on treatment, then the risk would be zero. If they were not on treatment the risk might still be only 1 in 300 or lower.
You cannot guess someones HIV status so your assumptions might also be wrong.
You started PEP within 48 hours, so it is likely it will work.
PEP – stands for Post-Exposure Prophylaxis. It is a term used for taking HIV drugs to reduce the risk of infection. PEP usually involves taking a combination of three HIV drugs for one month. The earlier PEP is started, the more likely it will work. Ideally, this should be within a couple of hours. If this is not possible, then still the earlier the better.
Some guidelines include a two-day window to do this (i.e. within 48 hours). After this, effectiveness is much less likely. Other guidelines allow up to 3 days (i.e. within 72 hours). Sometimes this may be more for psychological benefit. For example, if someone is very stressed or traumatised.
No guidelines recommend starting PEP after 72 hours.
After finishing PEP you need to wait a 4-6 weeks before testing.
If the PEP has worked, or the person was not initially infected, this will show as a negative HIV test. The test you did 17 days after the exposure will not be accurate yet.
If the PEP has not worked, this will be shown in a positive test result. Testing 4 weeks after PEP will detect 95% of infections. Testing after six weeks will detect more than 99% of infections. This result doesn’t need to be tested again.
If PEP has not worked, serosonversion usually occurs 1-3 weeks after PEP is finished. However, only 80% of people show symptoms.
Please test 6 weeks after you finished PEP is finished. If you test any earlier, you need to take a second test 3 months later.
Viral load (PRC) tests are not approved to test for HIV. In some cases they can have a role.
Please see a doctor to talk about your symptoms he best way to confirm what is causing them is to see your doctor. He/she will be able to diagnose and treat the symptoms accordingly.
Please see this link for more information about PEP:
https://i-base.info/qa/factsheets/pep-faq
Note: This answer was last updated in July 2021 from an original post from December 2011.
Thank you Roy for your earlier answer. This is a follow up on my previous questions.
Recall I had protected and unprotected sex with a woman who initially didn’t know she was HIV positive on the 26th of February. Viral load 42,800 and CD4 count of 146. This information was from future tests on her
I started a course of Mylan Tribuss 6hours after exposure. The medication has M171 written on it and made by Mylan India. I have not had any ARS symptoms
The unprotected part of the insertive vaginal sex was like 2 minutes but I did give her deep oral sex
Do you think if the PEP is not working I would have had ARS? I did a baseline test which was negative. Do you think a test at the completion of the PEP won’t likely change even if not guidelines??
Most importantly Roy, do you think taking the PEP for 56 days straight would be more effective than the usual recommended 28 days in case some pockets of the virus are hiding and may wake up after stopping the PEP???. I ask this because I have read some disturbing articles on a CSW who had occupational exposure and tested negative after PEP but serocoverted after stopping the medication. Further tests revealed some pockets of the virus hid in ger cells and kind of woke up when the meds was stopped. Do you then think a double course of uninterrupted PEP would be beneficial???
I greatly appreciate the work you guys are doing here. God bless
Hi Sylvia,
I’m so sorry to hear your story.
But it’s not really possible to answer your question about the chance for a negative result. However, it’s good that you’ve started PEP. And when you did this it was only just over 48 hours after the exposure.
On sunday 03 march around 5 o’clock in the afternoon I had sex with the dude that I recently meet and I was sure that the condom was correctly inserted unfortunately the dude managed to remove the condom without my knowledge. When we were done it was by then when I realized that I had an unprotected sex with the dude. On Monday I went to the doctor with him and he tested positive and I was negative but because the area is not used friendly I was able to get the trivenz pills on Tuesday afternoon and I was advised to take the pills at night because of the side effects. I started taking them on Tuesday evening around 6 o’clock. Do I have a chance for my results to come negative?
Hi Spencer,
Unfortunately it’s not easy to answer your questions because they depend on factors such as how soon did you start PEP. But please see this link for more info about PEP.
Was your partner able to access HIV treatment?
I had protected sex with a lady for a few minutes and then rounded off without protection for like 2 minutes. I also gave her deep oral sex. This happened on 26th Feb. Tested her a few minutes after and discovered she is positive. I would eventually discover her viral load is 42,800 and CD4 count of 146. She had no idea about her condition at this time. Initiated PEP of a single dose daily combo of 3 cocktail
My question: Is there a chance of escaping this issue? Would the PEP work if I diligently complete it?? I heard a test on the day of completing the PEP is a good indicator even if not conclusive…are these true???
Hi Thab,
Thanks. Once you’ve finished your tests to confirm you’re HIV negative, is it possible to access PrEP? Here’s a link to the guide to PrEP, PEP. PEPSE and TasP
I am a 25 year old male. Condom broke with an HIV positive female prostitute on 30 November 2018. I started Odimune which has emtricitabine, tenofovir and efavirenz as PEP post exposure prophylaxis 27 hours after exposure. Condom broke before ejaculation. I am circumcised. I tested one month after PEP which is two months after the incident or exposure. The test is HIV Elisa 4th Generation which has 18-21 days window period.
Before the above incident i also had a broken condom with another female prostitute whom her status i could not confirm and i can presume that she was postive too. That was around late September 2018. I also started Odimune which had emtricitabine, tenofovir and efavirenz as PEP post exposure prophylaxis 17 hours after exposure.
I only got tested after the second incident one month which is 31 days after PEP completion which makes it two months after the incident or exposure. The test is HIV Elisa 4th Generation which has 18-21 days window period.
I can say i do not learn from my mistakes, i was so worried. This time i will never keep on repeating such mistakes. I will no longer have sex with any person whom i do not know her HIV status since condoms can break. I am lucky that i am still HIV negative. I will further test three months and six months just for the sake of convenience. I am writing this for the purposes of those who will base their questions in this site as an evidence in addition that PEP does work and help.
Hi Mike,
When did the 3 days worth of PEP run out? What was the risk?
I was give 3 days of PEP at a public hospital, but, they did not give me PEP for the other 28 days. They did not even told me I needed to take it for 28 days. What should I do???
Hi Michael,
Please see this Q&A about keeping a few pills in case PEP is needed in the future.
i-Base information always stresses the earlier PEP is started, the better chance it will work. This should ideally be within hours. There is no data to show there is any difference between 26 days or 28 days of PEP, so you can easily do this with little likely impact on the efficacy of PEP.
So missing just one dose of Truvada is not likely to change the outcome of PEP. What other meds are you taking with Truvada?
However, do you think you might be at risk of HIV again in the future? If so, it might be a good idea to ask at the clinic if you can be given Truvada as PrEP to stop any future risks.