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 Radix, if your partner was on treatment and has an undetectable viral load, there is zero risk. This means you wouldn’t need PEP.
Please see this link for more info about PEP, whioch also explains this:
https://i-base.info/qa/factsheets/pep-faq
I had sex with an Hiv positive lady on Sunday early morning at 3am, (that was after Saturday party ). I realised she was HIV positive on the same day Sunday at11 pm( at night ) after testing from the clinic.
The Nurse gave me Pep immediately because I had not yet made 24 hours after exposure…
Do I stand higher chances of not getting HiV ???
Hi Lindi
For the short time you are on PEP, this will also work as PrEP, but not for the last week. Please see this link for more info about PEP:
https://i-base.info/qa/factsheets/pep-faq
Please also talk to your doctor about switching to PrEP when the PEP finishes, if you are worried about still being at risk:
https://i-base.info/guides/prep
Also, and this is important, if you agree to sex with your partner with a condom, he changes your consent if he later takes the condom off. This invalidates your consent and he is now technically assaulting you.
Assault is a criminal offence and he should understand that this is serious.
You might want to think about whether you want to have a boyfriend who assults you in this way.
Hi I’m currently on Pep for the past 3 weeks. Im not sure of my partners hiv status ,he keeps postponing getting the test done. Recently I have been suspecting that he has been removing the condom during sex. If he is positive will this affect the efficacy of the Pep that I’m currently on.
Hi Joshnon, please see here: https://i-base.info/qa/factsheets/pep-faq
Hi doc, I am on my 20th day on PEP,(Acriptega),had sex with someone who we found out later that she was positive,condom slipped off and I stopped immigrating, took pep within 6Hrs, I am just so stressed out that i take hiv test every week,is there possibility of getting hiv? I drink the pill everyday at 13:00,can this affect the outcome?
Hi A, please see here: https://i-base.info/qa/factsheets/pep-faq
I had sex with an hiv woman 2 rounds of 5minutes each. I tested and was still negative. After 48hours, I started pep. What is the risk of becoming hiv positive
Thanks, Simon. Really appreciate your reply and all the good information on this site. My RNA test on day 27 post-PEP was negative. I am interpreting this as conclusive. Couple things I learned in this:
1) getting PEP was far easier than I expected. I was able to use an online service, answer questions, and pick up the meds a few hours later. Anyone concerned about a possible exposure but deterred by a perceived challenge in getting PEP privately, should know it is actually very easy to get and can be done very privately – possibly even online.
2) The extended time to reach a conclusive test result after PEP is itself a deterrent to taking PEP. The anxiety of not knowing for an extended time (10 weeks post-exposure?!), for some people, might outweigh the decision to take PEP. I hesitated for that very reason. Access to RNA testing would solve this even if the patient has to pay more out of pocket. (I paid the equivalent of about 96 GBP.) According to the link you shared, the RNA test should be conclusive about 2 weeks after completing PEP, which is equivalent to taking a 4th gen test 6 weeks after exposure without PEP. That puts the time to reach a conclusive test result about the same with or without PEP, eliminating that deterrent – if you can access an RNA test after PEP.
3) I’m sold on PrEP. But it turns out it is harder to get than PEP due to the additional blood work (related to kidney health) that is required before starting PrEP. There is a regime called 2-1-1 on-demand PrEP. This is a really good idea to help reduce hiv transmisison. I hope this becomes more widely available.
Hi Kamau, please see here: https://i-base.info/qa/factsheets/pep-faq