[Question #3083] Fourth Generation Screening test positive but differentiation conf antib negativ

39 months ago
Hello Dear Dr Hansfeild,

I am extremely stressed out with the results. Please help understanding.

Background.

Had protected insertive vaginal sex on 09/28 and 10/2 with a high end CSW(white) in UK. Condom did not break , slip and when came out it was intact. 
Both times had unprotected oral sex(received).
Had protected (condom)vaginal sex again on 11/20 with the same person.
Recevied unprotected oral sex.
All 3 times checked the mouth from outside and did not see any lessions, ulcers or bleeding(of other partner).
Recevied unprotected oral sex from a nurse on 12.02.
I went for testing as I like to get a 3 month test done.
My last Fourth Generation test as of august 23rd both the duo and the hiv rna were negative.
I went for testing on December 11th again and my duo 4th generation came back reactive but the confirmatory diffrentition test came back negative for both hiv 1 and hiv2 . I am being told by the lab they are not reporting the final results as they are running the HiV RNA TEST on the specimen.
I was not sure so I went in today and gave another sample of hiv rna test making sure they have enough sera sample left.

Question.
I practiced safe sex and the only unsafe part was unprotected oral sex. Could this be a false positive.
I do not have any symptoms except 10 days back had a mild sore throat and myalgias. I think it as my sinuses and I took steroid nasal spray and humidifier and it helped me. At the present time I have no complaints. 
Worrying like crazy . please help me decipher the lab tests.
Edward W. Hook M.D.
Edward W. Hook M.D.
39 months ago
Welcome to the Forum.  I'll try to help.  I completely understand your concern.  The exposures that you describe were very low risk.  CSWs of the sort you describe rarely have HIV.  Even if your partner did, the encounters you describe were highly protected.  There had NEVER been a case of HIV proven to have been acquired from receipt of unprotected oral sex.  Similarly, even if your partner happened to have HIV, since condoms reduce the risk for HIV acquisition 99.9%, your risk for acquiring HIV from condom protected sex would be less than 1 infection per 1,000,000. 

On the other hand, there are occasional false positive combination HIV antigen/antibody tests which occur for reasons that are not well understood.  I anticipate that the further differentiation tests and your HIV RNA test will be negative, proving that the test results are falsely positive.  This is the result to expect.  Please let us know what your follow-up tests show.  EWH 
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39 months ago
Thanks for the kind words.
I see you mentioned the differentiated test will return...
My differentiated test for hiv 1 and hiv2 is back and they both are negative.
Do you think since my last exposure was 11.20 if we do not count 12.02 as oral sex exposure as meanigful, THE TIME between 11.20 to 12.11 would just show Hiv Rna since the antibody test is confirmed negative.?
Edward W. Hook M.D.
Edward W. Hook M.D.
39 months ago
The three weeks between 11/20 and 12/11 is a bit short to be completely confident that antibodies would have appeared- they would be present in some but not all patients at that time.  That said, when considered in the context of your risk, the accumulating evidence is showing that your test was falsely positive.  I am confident that the RNA test will do the same.  At that time, you can, with a negative RNA test, you should be entirely confident that you have not acquired HIV from the exposures you mention and that your recent test was falsely positive.   EWH
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39 months ago
But since  if one of them was the same person as I did with  on 09 28 and if the duo test is positive but the differentiation confirmation test on both hiv1 and hiv 2  is negative that would make it 10 weeks almost. So I am thinking out loud that is enough time for the antibody to be positive and would have rendered the confirmation differentiation test also positive.
Is 10 weeks enough time for the differentiation confirmation test also to be positive is my question?
If so then in my case so far it negative.
I am worried about the p24 antigen part which is not picked on the differentiation test?
Any thoughts regarding the 2 points above.?
Thanks.
Edward W. Hook M.D.
Edward W. Hook M.D.
39 months ago
I think you are over thinking this.

At 10 weeks antibodies would certainly be present.  Read my earlier comment and stay focused- it was in response to your questions about exposures on 11/20 and testing on 12/11.

the p24 antigen testing is taken care of by the RNA test. 

This is my 3rd and thus, as per Forum Guidelines final response to this thread.,  further questions will not be answer (either as part of this thread or as a new thread) until you have gotten additional test results as there is nothing more to be said.  I will keep the thread open so you can post the results of your RNA test which should be available in short order.

One final comment.  Another way to address your continuing concerns would be to tell your CSW partner and arrange for her to be tested.  If she is negative at this time, she could not have infected you.   EWH
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39 months ago
I got my hiv 1 rna testing and its negative(not detected). 
So intial screening test indeed was a false positive one. 
Thank you so much for your earlier feedback and the great work you do.
I know I have reached the limit but kindly consider answering this . 
Do I need to go get a hiv2 viral Pcr test. ? I have never travelled to west Africa and have always used condoms for protected sex with unknown partners.
Edward W. Hook M.D.
Edward W. Hook M.D.
39 months ago
Great.  While I am not surprised to hear the result, I know that it is a great relief to you.  Believe the result and put your fears behind you.  No need for further testing of any sort, including testing for HIV-2.  Believe the result.

If and when you test in the future, be sure to let your provider know that you have had a falsely positive test.  While in many instances these are transient, on others they persist.  In addition, I would suggest you find out the brand of test which gave the false positive result.  Tests vary and your chances of a future false positive test are a bit higher with the same test than with a test manufactured by a different company. 

This thread will now be closed.  Take care and please do not worry further about this result.  EWH
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