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 Jay, there as your partner has tested negative there is no cause for concern. Please follow this link for more information about testing and transmission: https://i-base.info/qa/factsheets/hiv-transmission-and-testing
Hello,I have a question a couple days I ago I had a sex with a girl during the sex I found out my condoms tearing(I don’t know when )but when I found out I immediately taking off and put new one…. i ask my partner she had negetive hiv test on 10th May… I had sex with her on 1th June I force her to do it again and the result on 2th June was negetive… it might she infected me to hiv? I’m so neverous
Hi Terry, given that you have completed your course of PEP and started within a suitable time, it is very likely this will work.
HIV is not readily transmitted and a number of factors change the risk of transmission. After PEP, a test is conclusive a minimum of 6 weeks after.
Please follow this link for more information about testing and transmission: https://i-base.info/qa/factsheets/hiv-transmission-and-testing
I got into sexual activity with a lady for the first time thou I was tipsy by alcohol.. around 10/11pm we engaged into sex after all I realized I never did that with a condom so I was worried about 6AM the following day I took her for a screening test which was confirmed positive.. which I put a call to a doctor and he directed me to visit any nearby health center with I did. I was given pep(dolutegravir-lamivudine-tenofovir)which I took by 4pm that day and I have kept to the 4PM everyday for 32days now and I’m done with all tablet s …please I need your expert advice I have been filled with anxiety..what’s my chances of getting the infection after taking pep correctly and I avoided alcohol always…I tested negative after taking the drugs of the that..
Hi Francis, your results are conclusive. You are HIV negative. There is no reason to continue testing.
It is best to speak to a doctor about your symptoms – especially as you have been experiencing these pre-exposure.
greetings Josh,
Hope you had a great day…? Just to update …. Well still feeling some funny symptoms since after PEP …. Since after pep i have been testing testing testing..severally did .Alere HIV Determine 1/2 have done baseline and after Pep also after every 10 days after pep…today did an Elisa Ab/Ag test post 59days of exposure and post 26 days after PEP….which i got a value of 0.15 negative…. Should this be conclusive
Still having my funny symptom since after pep so if I rule HIV out I can focus on my present symptoms since some of them I have been having years ago before exposure…
Hi Olu, I am sorry to say that there is no evidence to suggest that this would work. How risky was your exposure, if at all? In the UK an exposure would need to be high risk to be considered for PEP. This is a link that may help you determine your own risk: https://i-base.info/guides/testing/risks-for-transmission
Good day, please is it possible for PEP to be effective on day 4 ( 96hours after exposure)… And taken daily for the 28 days regimen, will it work??
Hi Chike, as the condom did not break there is not risk of transmission. This is confirmed by your partner testing HIV negative.
These results are conclusive and you are safe. There is no reason for you to be on PEP.
Hello josh. Had condom protected sex with a lady. The condom didn’t break as far as I can remember but i saw blood on the condom after. I believe she was just starting her menstrual cycle I felt discomfort at the tip of my penis after and also the 2 next days(no pain urinating or discharge, took antibiotic and it stopped immediately) .
Started pep 63 hours later just to be safe.
She tested negative using 4th gen lab test 28days post our encounter and 40days post her own last exposure. Is it conclusive for her and am I safe. I am worried.