HIV Testing & PEP

[Soscaredpleasehelp]

Hi Doc,

A month ago I had an encounter with a Tran-sexual sex worker. All activity performed was done with a condom(both of us)...I was the receptive partner of intercourse. However I was extremely anxious about this encounter so I went to the hospital and received Combivir 150/300 anyways.  Today is my last day on the medication.

Afterwards,I went to an HIV specialist who from the start said my encounter didn't warrant PEP.  My specialist tested me at 3.5 weeks (23.5 days later) with a rapid test and also a blood test to lab (the test states HIV 1/2 plus O EIA on the results).  The results were negative.  My doc told me that HIV would effect a PCR test looking for viral load, but not an antibody test.  He said if I was infected my body would fight the infection and produce antibodies regardless of PEP.  Since my first visit to this doctor he said my chances of infection are as close to zero as possible yet I still remain worried.  He told me the test I took is very sensitive.  He also told me that almost every positive diagnosis he has made with the antibody testing he currently uses is positive by 2-3 weeks almost always by the 4th and he has rarely seen someone come back positive after they testing negative at 4 weeks.

He also told me that with my very low probability of infection since the encounter was protected and with my negative test at 23.5 days, he would be MORE than shocked if I came back for a positive test in the future.

He told me that condoms are very effective, and if it broke, it wouldve been obvious.

Does PEP effect antibody testing?

How reassuring should this negative antibody test be at 23 and a half days if my doctor is using advanced testing that is highly sensitive to picking up infection?

Do you agree with him on my testing being very reassuring at this point?
If the condom did fail, would it have been obvious?

Regardless I have a follow-up test in 3 weeks which will be 7 weeks.

[Soscaredpleasehelp]

Hey Doc,

Thanks for the response, one last question:

I know that by 24 days regardless of PEP antigen/antibody testing would pick up infection....but, in your professional opinion, what percentage of infection would be detected by antibody testing alone at that time frame?

I've read some very contradicting information, however my doctor has told me that the newest antibody testing is very sensitive, and regardless of PEP, with patients he has done antibody testing on, almost nobody comes back positive after showing negative at 24 days...

Thanks!

[Dr Sean Cummings]

Hello

Thanks for posting....and stop worrying.

You have an excellent and extremely well informed doctor who has given you completely accurate information.

All the facts you have relayed are correct.

I would not have given you PEP either - you did not need it. You had receptive anal penetrative sex with a condom which WILL have protected you. Condoms are highly effective at limiting the risk.

PEP does alter HIV testing results. PCR's are not reliable during PEP because the object of PEP is to suppress viral replication which is what the PCR is looking for.

HIV antibody testing after PEP is also problematic in that we - doctors - worry that we PEP may have altered the body's response to the virus. However, what I can say is that in our patients who have definite very high risk unprotected exposures with known HIV positive people who are treated with PEP, and who then test negative with an antibody or antibody/antigen test at the interval you were tested at, do not go on to become HIV positive later.

So in summary, I'm saying exactly what your doctor has told you already.

You are not HIV positive. You can see further information on HIV testing on our main site

http://www.freedomhealth.co.uk/sexual-health/hiv-test-hiv-testing-london/125/

best regards, Sean

[Soscaredpleasehelp]

Hey Doc,

I understand but what I was actually asking is:  

Have you personally at your clinic seen failures with PEP? Has anyone had a positive test while they were on PEP? Not someone who tested negative at the end of PEP, but someone who was on PEP and tested positive towards the end of there regimen or directly afterwards?

Sorry about the confusion

[Dr Sean Cummings]

""HIV antibody testing after PEP is also problematic in that we - doctors - worry that we PEP may have altered the body's response to the virus. However, what I can say is that in our patients who have definite very high risk unprotected exposures with known HIV positive people who are treated with PEP, and who then test negative with an antibody or antibody/antigen test at the interval you were tested at, do not go on to become HIV positive later""

[Soscaredpleasehelp]

Hey Doc,

Just wondering if you have ever seen anyone test positive (specifically for antibodies, if not then also the combo test) while towards the end of their PEP regimen?

Thanks in advance...just a little nervous bc I'm going for a 6 week test next week, and while it won't be conclusive, it will be highly encouraging.

[Dr Sean Cummings]

Hello,

I don't think I can make any more advance on what I've written already I'm afraid:-

""HIV antibody testing after PEP is also problematic in that we - doctors - worry that we PEP may have altered the body's response to the virus. However, what I can say is that in our patients who have definite very high risk unprotected exposures with known HIV positive people who are treated with PEP, and who then test negative with an antibody or antibody/antigen test at the interval you were tested at, do not go on to become HIV positive later""

I can't answer your question any more specifically as that information is not available.

Best wishes, Sean