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.
Note: This answer was last updated in July 2021 from an original post from December 2011.
Hi Ahmadu, is this girl alright and has she agreed to take the test? You cannot make someone take the test otherwise this is considered assault.
PEP is given on the basis of the risk of exposure inc. viral load, treatment, type of sex and other infections.
Information about starting PEP can be found here: https://i-base.info/qa/factsheets/pep-faq
I had sex with a girl i suspect to be Hiv positive because she had karposi sarcoma im taking her for test if positive im i to start pep emeditely?
Hi Bibi, there is no way to tell if PEP has worked before these 6 weeks. This is why this window is needed.
As you had used a condom and changed immediately after realising it was broken, the risk of HIV is minimal.
For more information about testing and transmission please see here: https://i-base.info/qa/factsheets/hiv-transmission-and-testing
Hello, i had sex with a lady who is hiv postive, in the process my condom got torn but i changed immediately. I started pep after 65hours and i completed on 30/01/2024.I have tested and im negative.What are the chances that the lady infected me? How can i know that pep has worked before the end of 6weeks?
I had sex with a girl and prior to the sex we planned on taking an HIV test before we commenced the sex but somehow we skipped it and after the deed was done I insisted we do the test and we did it and her result turned out she was positive and i immediately began the PEP in less than 24hours and the PEP has 30 capsules in it and because I was being very religious and steadfast with taking the medication I realized I finished the whole 30 capsules, and I totally forgot I was told to take it for 28 days.
So my question is, will there be any consequences for taking 30 tablet instead of 28 tablet?
Hi Mike, there will be no consequences for continuing PEP for these additional 2 days.
More information about PEP can be found here: https://i-base.info/qa/factsheets/pep-faq
Hi Pedro, this is a conclusive result. You do not have HIV and there is no risk to your girlfriend.
For more information about testing and transmission please see here: https://i-base.info/qa/factsheets/hiv-transmission-and-testing
Hey! 3 months ago I was doing a surgery internship in Cape Verde and, when closing a patient, I pricked my finger with the needle.
We both did a HIV rapid antigen test and we were both negative. But because the patient had multiples partners at that time, I was afraid he was on a window period, so I did PEP for 28 days as prescribed. I had no symptoms whatsoever.
Now, 83 days after the accident, 55 days after finishing PEP, I did a 4th gen HIV test which came out non reactive (0.24).
Can I be sure I’m HIV negative? I wanted to have unprotected sex with my long-time girlfriend, but I want to be 100% sure first.
Hi Daniel, as your partner had a viral load of 19 at the end of the 4 days without treatment there is no risk of resistance.
Resistance is only a risk after viral load rebounds after being on treatment. A viral load of 19 is undetectable and is still low enough to be sure that treatment is still working.
For this reason U=U can still apply and there is not risk of transmission while having sex without using a condom.
Hi ..Am Daniel…Am so sorry for disturbing you but I still want to ask some questions….
. during October my partner who is HIV positive skipped his drug for four days because it has finished….it was on the fourth day he went to get his drugs from the hospital and that was when they did his viral load test and he was 19 copy/ml which is undetectable …..so all this happened last year October…. My first question is dat I hope the drug he skipped will not affect his viral load…. secondly I hope the drug won’t be resistant because he skipped them for those four days……The reason am asking is because i had unprotected sex three times with him this January and I am HIV negative…. please brother help my life.