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 Jojo, to confirm your result after PEP the earliest you can test is 6 weeks after the last dose of PEP. You will need to use a 4th generation test and the result will be conclusive.
Hi I started to take pep within 72 hours but I took blood for laboratory I’m negative
I finished. What are chance of been positive and I took blood after pep wait for the result
Hi Mary, please see here for more information about transmission: https://i-base.info/guides/testing
Hi, I’m a dental student and after an extraction of the patient who was positive I got poked by a probe which was used by the patient I had gloves on though and I think some blood leaked into the glove where I poked myself, she was on medication though I didn’t ask for how long she has been taking the medication. I’m on pep right, so are the chances of me getting infected high and if not should I continue pep
Hi Flavia, PEP should only be started within 72 hours of an exposure. Starting PEP on day 13 is too late after an exposure for it to have any impact.
More information about PEP can be found here: https://i-base.info/qa/factsheets/pep-faq
I started on pep after 13 days but still scared l might have contracted the virus
Hi Kasaya, for more information about testing and transmission please see here: https://i-base.info/qa/factsheets/hiv-transmission-and-testing
I have tested after the last dosage of PEP as follows: 6weeks after, 10 weeks after, 14 weeks after, then 18 weeks after the last dosage of PEP. All tests have been negative. The doctor told me to tested again after 6 months (26th week). It’s now the 6th month after the last dosage of PEP. I am abit worried perhaps may test would turn positive. I had an exposure to HIV after I slept with a HIV positive lady who has been on ARVS treatment plan. Last year, 2023 December I developed lymph nodes in the armpits, groin and under the chin. They have never gone away. They are still present. Their sizes is still the same, and are painless. I also started experiencing arches in my souls of my feet starting the February of 2024. The arches are still there. I again have very small spots of dots like rash every part of my body. They are non itchy. Am I seroconveting?
Hi Daniel, for more information about transmission please see here: https://i-base.info/guides/testing
What if someone is circumcised and the condom breaks immediately u pool yourself out will you contract the virus ?