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 Peter, how long after finishing PEP did you wait before taking a test? Depending on the type of test you have used, they will not be accurate until at least 6 weeks and some can take up to 12 weeks after PEP. As you started PEP within a suitable amount of time it is very likely it worked – if there was a risk to you.
As for testing your partner while she slept, this is difficult. HIV testing requires consent from the individual. Other than encouraging themselves to do another test this is information that can be difficult to share.
Hi am Peter,I had an mouth oral and sex with a bar seller girl,the following day i told her we go for test but she told she it make it because of job,I went to vct expluaned to the doctor and I was tested I was negative snc given pep,I started pep on 44 hrs.i told the doctor to give me self test kit..I went met the girl i had sex with tested her while she was a sleep..and the test came positive..i didn’t tell the result but I completed my drug yesterday advice me
Hi Pit, taking PEP as early as you did is great. This means it has the best chance of working.
Sexual fluids/menstrual blood only transmits HIV if it comes into contact with broken skin or glandular tissue – head of the penis, vagina or rectal tissue. As you used a condom, regardless of how high there is no risk of transmission.
Pit here again . Just to be clear, I said I was a little bit drunk but used a condom and then later realized she had just finished her periods. How contagious are menstrual/sexual fluids. And secondly the lady declined from having a test done . But all in all, I have been taking PEP since 53 hours after exposure. Thank you
Hi Pit, PEP is effective if taken within 72 hours of exposure. As you have done this PEP will have the best chance of working.
What do you mean by the condom being ‘a little high’? Using a condom prevents HIV transmission. As long has the head of the penis was covered. There is no risk if the base of your penis came into contact with sexual/menstrual fluids.
Do you have a reason to believe this woman is HIV positive?
How effective is PEP after 53 hours. Used a condom but was a little high then noticed the lady must have been finishing her periods. Tried to get her to test but in vain . How safe is my situation?
Hi Richmond, was what you have described the initial exposure you had? If this is the case there is no risk to you.
As you were on PEP for the full course and started so soon, it will have the best effectiveness. Meaning it is very likely to work. Though in this exposure, the need for PEP is not present.
Unfortunately the tests you have taken are not conclusive. They are good signs but it is too early for these tests to work. The 4th generation test will be conclusive from 6 weeks after PEP. The rapid antibody test will require 12 weeks (3 months) after PEP.
Hello Josh, i recently finished my PEP regimen (on 4th May) they drew Blood from my veins & ran a laboratory 4th Gen Test Analysis which is Negative.. Ị completely adhered to the 30 day PEP regimen, didnt miss any dose or fail to took it at the exact time, started within 24 hours.. Now, is it a good Sign that i finished/Tested Negative & That it wont change without further exposure? Out of fear, i ran an Alere Rapid Antibody Test again today, 17th May which was Negative too (2 weeks after PEP, 44 days after a presumed exposure, cos ị had a protected Sex with a suspected HIV positive Girl, noticed Blood on the Condom & some of the Blood on my pubic hairs but the Condon didnt Broke nor tore & ị dont have any cut or laceration on my skin) should i be worried?
Hi Francis, thank you for further clarifying your point. Have you spoken to a doctor at all about these symptoms? Given that not all have gone away since stopping PEP it would suggest something else. However, given the precautions you have taken e.g., starting PEP in time and finishing the full course, seroconversion is still not the likely cause of your symptoms.
I imagine waiting for the antibody tests can be scary. Each test you have taken is negative. With each test until the date passes it is conclusive, it does reduce the chance that you will test positive. Please follow this link for a guide about anxiety around HIV testing: https://i-base.info/guides/testing/hiv-testing-feelings-of-fear-anxiety-and-guilt
It is good to hear that your friend has started treatment. This is really good news.
I feel my write up wasnt clearly understood so had to reemphasize
My test was done 40 days after exposure(April 5) not the day I finished pep… Which was About 8th May 33days..
I commenced PEP under 72 hours around 66hours mark…
Took pep regularly for 33days(added some days) ..it was an up and down symptom feeling throughout the pep course…esp tingling sensation on my legs , joint and muscular pain, dreams, bloating stomach, feeling unwell towards the end of the regime..
Some days After pep only the tingling /peripheral sensation on my both legs started reducing.
Then started muscular twitches even in my armpit, joint pains , itchy or pinching sensation intermittently on my body, progressive fatigue. movement on my skin and I won’t see anything, internal heat (having a cool bath helps but no specific fever), lack of appetite…not feeling the same pre exposure…..
Am just scared feeling this way knowing the fact that its only an antibody test that can conclude how I feel….and I still have weeks to go…so sad am really hoping PEP worked…an am not seroconverting
As per my friend she has commenced treatment….
This communication really helps…
Thanks to the team