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…had unprotected sex with a HIV positive and started pep at 71hrs what are the chances it will work
Hi V Scared
I am sorry that you were assaulted in this way. If you agred to have sex using a condom, and your partner takes this off without telling you, thus cancels your consent to having sex with them. It is assault.
Because this was such a short time, it is unlikely to be a risk of HIV, even if your partner was HIV positive.
You are right that a viral load test can show whether your symptoms are related to HIV. Although not generally used or available, on the NHS to test for HIV, this might be provided if you ask, because you were assaulted.
Your questions are included in this factsheet on PEP.
https://i-base.info/qa/factsheets/pep-faq
Possible exposure via receptive anal when date removed condom and reinserted without consent. I immediately ended the session and kicked him out. He claimed to be on prep and tested neg one month prior, but who knows if that’s true.
Started pep 40 hours later, with Truvada only because the pharmacy didn’t have DTG. Added DTG about 24 hours later. Completed full 28 day regimen, taking pills same time each day +/- 1 hour. Tested neg by RNA at day 11 and 21 (probably meaningless) and neg by ab/ag at 5 weeks, 1 week after finishing the pep.
Today is day 55 post exposure and day 27 after finishing pep. I’m sick. Started 5 days ago. Nasty headaches, fatigue, fever and chills, along with a sinus infection and cough. No rash. Even though the odds would seem to be in my favor (brief exposure, source claimed to be on prep, properly started and completed pep), I’m absolutely terrified, so I took another RNA test today.
My question: If my symptoms are associated with acute hiv infection, there is no chance for an RNA test to return a false negative, correct? If the symptoms are caused by an active seroconversion, surely the viral load would be well into detectable range. Therefore if the RNA test is negative, I can be certain my current symptoms have nothing to do with hiv? But I still need an ab/ag test at 12 weeks anyway?
Hi Baloyi, ARVs can prevent transmission. As she is on treatment it is likely she has a suppressed viral load. This means that HIV transmission is impossible even without a condom. This is explained by U=U: https://i-base.info/u-equals-u/
There are a number of things that can change the risk of transmission. More information about this can be found here: https://i-base.info/guides/testing/risks-for-transmission
I had unprotected sex with a lady (3 rounds in the space of 5 hours) she subsequently told me that she was hiv + but claims she was on consistent ARV treatment. I immediately went to the Dr and got PEP (reydin) and started treatment.
1. Does my chances of contracting HIV increase because I had three consecutive rounds of sex with the same lady?
2. Does ARV treatment reduce chances of transmission?
Hi Jimjim, for information about transmission see here: https://i-base.info/qa/factsheets/hiv-transmission-and-testing and for information about PEP see here: https://i-base.info/qa/factsheets/pep-faq
I had unprotected sex with a lady, after she tested positive for HIV, I started PEP with TLD with in 36 hours, I’m very worried, please help.
Hi Were, please see here for information about transmission: https://i-base.info/qa/factsheets/hiv-transmission-and-testing and here for information about PEP: https://i-base.info/qa/factsheets/pep-faq
I had sexual encounter with a person I didn’t know her status and the condom broke..
I was much worried so I immediately went for pep with out testing…. Is this bad… What are the effects? I suspect the person is hiv positive
Hi Mido, as both you and your partner tested negative 51 days after the exposure there is no risk of transmission. You were not exposed to HIV.