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 Daniel, there is no risk because of U=U. As your partner is on treatment and undetectable it is impossible to pass on HIV via sex. There is. no risk to you.
For more information about U=U please see here: https://i-base.info/u-equals-u/
Hi…Am Daniel…I had unprotected sex with my male partner who is HIV positive although he is undetectable as at October last year and he is constantly taking his drugs, I am gay and bottom (the receptive partner)…I only took this risk because I am aware of the U=U…. please advice me,I am still scared… Thanks.
Hi Fred, this is not a risk for HIV transmission. For more information see here: https://i-base.info/qa/factsheets/hiv-transmission-and-testing
Starting PEP within 72 hours is effective. For more information see here: https://i-base.info/qa/factsheets/pep-faq
Hi josh, i had sex with a CSW, 4 hours before the deed (1pm) i had trimmed my pubic hairs and had a small cut on the base of the penis.. Around (5pm) the deed happed. The csw masterbate me for a couole of minutes then she put the condom on (durex invisible) then penetration comence but only lasted for 20sec since my penis is not that hard.. Then i remove the condom washed my penis with water then the csw ended it with a handjob..
Now my concerned is i am not sure if the condom covered my tiny small cut during that 20 second penetration..
Decided to take pep but it took me 70hours before i could take TENOF-EM and EFAVIRENZ since i had to source it from other city because it was not available on my city..
Took the pep religously for 28 days..
12 days post pep, im starting to feel muscle pains no fever no swollen lymph nodes..
Will pep work? Or is this a sign of seroconverion?
Thank you
Hi Sibusiso, why is it highly likely that this girl is HIV positive?
It is good that your doctor switched your to PEP. PrEP is to be taken BEFORE an exposure whereas PEP is for AFTER.
PEP is effective when taken within 72 hours of the exposure, however PrEP does contain the same drugs as PEP but instead of 3 drugs in PEP, PrEP only contains 2. This means the few days your were just taking PrEP it would still have helped to reduce the risk of transmission.
For more information about PEP please see here: https://i-base.info/qa/factsheets/pep-faq
Hi Josh,
Please advice. I have had an unprotected sex with this girl (status unknown but highly likely to be positive) around Saturday 6PM and around 9PM i took 2 PreP(my brothers PrePs i stole) and following Sunday morning went to the clinic to consult, tested negative and they gave me Tenemine (PreP) to start drinking which i drank second dose (1pill) at 9 PM and I was worried curious about my health if PreP will work, on Monday morning i went to the doctor and around 12:00 am and they instructed me to quit PreP and they PEP i drank one at 14:00 – which is 4 hours prior to my 48 hour circle. So my concern is, is it really gonna work ?
Hi Thando, no this does not mean seroconversion. The symptoms you have mentioned are common and can be caused by a number of problems. If you are still experiencing them please speak to your doctor.
Are you 6 weeks after the last dose of PEP? If you are you can now test using a 4th generation antigen/antibody test. This result will be conclusive.
Testing and transmission: https://i-base.info/qa/factsheets/hiv-transmission-and-testing
I have had unprotected sex with the male I had later found out is Hiv positive and not on treatment, I took pep within 24 hours, I tested immediately after pep and the test was negative. 3weeks post I started having joint pains and muscle ache, headache and stiff neck. Went to the internet and it said I have seroconvesion. In my 6th week and scared to test again, does this mean I contracted the virus
Hi Gigi, this is a very low risk of transmission. Using a condom and starting PEP within 72 hours means your risk is very low.
For more information about transmission please see here: https://i-base.info/qa/factsheets/hiv-transmission-and-testing
Hello, i hard a protected sex with somebody who is hiv postive but in the process my condom got torn, i immediated withdrew and changed the condom.I took my first pep within 72hrs.Is there a likelihood that my partner infected me?