Question
Does PEP delay seroconversion?
24 December 2021. Related: All topics, PEP/PEPSE.
Hi, I had an exposure in early October.
I took PEP (TDF + FTC + DTG) after 5 hours of the exposure. I did not accompany the doses with meals, I took them alone with water or some drink. Can this interfere or reduce its effectiveness?
Does PEP delay seroconversion in case of failure? At 5 weeks after finishing PEP swollen lymph glands in both armpit.
Answer
Hi, how are you doing?
PEP does have the potential to delay seroconversion.
As PEP works similar to medication used to manage HIV, PEP if unsuccessful can delay seroconversion.
This is why testing a minimum of 4 weeks after PEP is required. Seroconversion can occur 1-3 weeks after the course ends. Only 80% of those who do seroconvert in failed PEP will experience classical symptoms e.g., fatigue, fever, headache etc.
Five weeks after finishing PEP would be later than expected if this was really HIV. Swollen lymph nodes can arise from a number of infections, not only HIV. Is this symptom being managed by a doctor?
The combination you have taken can be consumed with or without food. This would not have impacted how well it worked as PEP.
If you have another question do ask,
Josh.
Hi Frank – this has already been answered. Please do not worry as the stress will make you ill.
Thanks for the reply Josh.
Appreciate that.
However the 4th gen test i did was a rapid test kit from finger prick, would you suggest i should get one more from the lab?
As of now my swollen lymph nodes on my chin and neck still persist and they started to sore.
Really hope its not because of HIV.
Will go for a doctor.
Just want to rule out the possibility, for a peace of mind.
Hi Frank, this result is conclusive. You are HIV negative. You do not need to do any further testing. Please follow this link for more information: https://i-base.info/qa/factsheets/hiv-transmission-and-testing
Hi Josh. Its 12 weeks post exposure and 8 weeks post PEP ive tested negative with abbott alere 4th generation rapid test and PCR RNA not detected. It the result conclusive?
Hi Jessy, an HIV rapid test requires 90 days AFTER exposure. Testing before this and the result is not accurate. A 4th generation test will be able to provide you with a conclusive result. 7 weeks is too later for an antigen test. These are not used to confirm status and they are only accurate for the first few weeks after exposure. Please follow this link for more information: https://i-base.info/qa/factsheets/hiv-transmission-and-testing
Hi, I this is Jessy again. I took a finger prick hiv rapid test on six weeks after completing PEP. It came out negative. I also took a P24 antigen test only at week seven post PEP(this time, blood was drawn from my vein). It came out non- reactive. Is it now conclusive that I do not have HIV.
PS. I still experience very light headache and occasionally tiredness.
Hi, no. Seroconversion needs to have occurred before this time. If it hasn’t you are not at risk for HIV. No follow up tests are required. This 4th generation test is conclusive from 42 days. You are HIV negative.
Hi Josh, thank you. This is really helpful. However, I have two more questions.
1. Is it at all possible that I still haven’t completed the Seroconversion process by day 42nd after completing PEP which is why the 4th generation test on day 42nd gave a false negative?
2. Do I need any follow test after a negative 4th generation test on day 42nd after PEP?
Hi KK, I apologise for the confusion. What I meant by don’t experience seroconversion is that this 20% will not experience the symptoms of seroconversion. In this case they will still go through seroconversion and test positive, however they will not have experienced any symptoms during this process.
Seroconversion is a process that is required for people to test positive. It is the process of developing HIV specific antibodies after becoming HIV positive. The initial symptoms can be experienced within a few weeks of exposure, however the process of making antibodies is slow. This is why some tests are not accurate until 90 days after exposure (the body has needed 90 days to make antibodies). Other tests like the 4th generation tests look for antibodies but also HIV antigens. These antigens are present in earlier infection which is why these tests can be accurate from 42 days after exposure.
Testing negative 42 days after PEP with a 4th generation test means you are HIV negative. This is a conclusive test. This means that the sore throat and lymph nodes you are experiencing are being caused by something other than HIV.
Hi Josh, thanks for sharing your knowledge. You mentioned 20% people don’t experience Seroconversion at all after PEP. However, I read in some article that HIV tests can only detect HIV after Seroconversion and before this period is the window period in which HIV tests are unable to detect HIV. So, those 20% people will always show HIV negative in tests while in reality they have HIV?
This is very confusing. Can you please explain this in detail and also the relation between Seroconversion and tests accuracy?
Also, coming back to in situation. If I test negative in 4th generation HIV test on day 42nd after PEP but still have sore throat and swollen lymph nodes since day 29th after PEP. What does it mean?