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.
Please see this link for more information about PEP:
https://i-base.info/qa/factsheets/pep-faq
Note: This answer was last updated in July 2021 from an original post from December 2011.
Hi Phumlile, information about HIV risk including PEP is online here:
http://i-base.info/qa/factsheets/hiv-transmission-and-testing
I had unprotected sex with my partner who I assumed was hiv positive and they put me on PEP with lamuvudine and zidovudine. Is this the right combination? I am currious cos the nurse took long to give the medication, she started calling other colleagues on the phone asking about the combination. She even confessed that she is clueless when it comes to PEP.
Hi Antony, information about HIV risk, including PEP is here:
http://i-base.info/qa/factsheets/hiv-transmission-and-testing
I had a protected sex with a lady whom l didn’t know her status but unfortunately the condom burst during the intercourse. Assume this lady was positive but on treatment, 1) what are my chances of being infected ?) 2)can l infect my wife ?) 3) what are the effects if l start pep after 24hrs ?
please see this FAQ page on risk and testing.
http://i-base.info/qa/factsheets/hiv-transmission-and-testing
On Saturday 11 2016 late night I had an unprotected sex with an HIV Positive lady we tested arround 11:30 Monday morning her results were positive mine were negative and quickly ran to grab my friends drugs which look pink in colour the drugs written 100 outside for her HIV treatment I then swallow one am scared to death what can I do is it a PEP these drugs but when am having sex with her I do not allow my sperm to penetrate I take my penis out a cud only sperm only on her chest but allowed the fluids of her arround my waist
Hi Sanko, in the UK PEP is only used if there is a high risk, which usually means knowing that your partner is at least HIV positive and not on treatment. HIV is a difficult virus to catch, but more information is at this link:
http://i-base.info/pep-and-prep
i have unprotected sex with a lady i thnk she might b hiv negative i wana start pep as soon as possible do you think it can help me pep
Hi Feni
Information about PEP and HIV transmission and testing are already online at the FAQ page.
http://i-base.info/qa/factsheets/hiv-transmission-and-testing
or in this guide:
http://i-base.info/guides/testing
You have an interesting life when you are unconscious! Your wife does not need PEP because this is too early for you to have been infections. Also, the treatment would have suppressed HIV even if you were positive.
HIV is a difficult virus to catch, so even without the PEP the chance of you becoming positive is likely to be much lower than 1% – ie there is a more than 99% chance that you didn’t catch HIV, even if you partner was positive.
I had sexual intercourse with a woman whose HIV status I did not know with condom but the condom burst. The next day, I went to the hospital because of suspicion and was put o PEP. I would be unconscious when ever I took the PEP. I refused to sleep with my wife. On the fifth while i just took the PEP and was unconscious, my wife raped me. on realizing that hours later, I told her I was taking PEP. the next day, I also put her on PEP. My questions are:
1. could I be postive?
2. if the virus was there, could I have passed it to my wife?
3. can I take PCR test to confirm my status?
4. Can see under take PCR to confirm her status?