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 Apphia, the only way to know whether you are positive is to have an HIV test. This needs to be 3-4 weeks after the end of the treatment (called PEP). HIV is a difficult virus to catch and together with the PEP you are much more likely to still be negative. If your partner was tkaing HIV treatment (ART) see this links for why the risk would be close to zero.
http://i-base.info/qa-on-the-partner-study
Hi had a guy we have dated for a year we have bn using condom last month we had sex widout a condom we went for a test after four days and my boyfriend tested positive,i waz put on pep tenofovir and anzanavir to take for 30days am taking my 30th dose today,can i be positive
I am not doctor but in the UK you would not have been given PEP. This is because of transmission is negligible when an HIV positive partner is on effective treatment, even if you don’t use condoms.
http://i-base.info/qa-on-the-partner-study
good afternoon Dr. I had an unprotected sex with a girl. Found out in the morning she was positive, i then ran to the medical center. They gave me pep. Two types. Since i was too stressed i took one pile twice a day by mistake on my first treatment. But the other two took them correctly accordingly. I am on my 10 day of treatment now.
Pls see this FAQ pages and the links at the bottom.
I have sex with a guy then found out the next morning he was positive. I started treatment that same day up until 28 days. What are my chances of contracting HIV
Information on testing and transmission is in this online guide:
http://i-base.info/guides/testing
I had an unprotected vaginal sex with a lady 8am and after I requested we get tested. I came negative and she was positive with one faint line. I went to my Dr who gave me AZT pep for 3 days. I came back to Dr and requested for the 28 days pep, the Dr gave me zidovudine for 28 days. The lady went and tested again and it was still positive, cd4 count 1580 and viral load below 40. What are my odds. Today made it 7 days exposure and pep but I want to go test first again with pcr HIV DNA?
Hi Munar, I have updated the original answer to cover your question:
http://i-base.info/qa/5255
For other information about testing wee this FAQ page:
http://i-base.info/qa/factsheets/hiv-transmission-and-testing
And this guide:
http://i-base.info/guides/testing
(1) Can PEP work after 6weeks of exposure
(2) Is rapid test at 4weeks and also 6weeks reliable
(3) I took PEP after 6 weeks of exposure, can it manipulate the test result at 12weeks of exposure