[Question #7497] Bioplex reactive but confirmation negative. (false positive or true positive?)

4 months ago
Hi doctor

Happy early holidays, I have a situation that has been really insane and I wanted to see what your recommendation is.

I had a routine blood work done that was done using bioplex apparently and my hiv screening came back reactive for hiv 2 in that platform. another fda differentiation assay was then tested and didn't confirm and was negative for both hiv 1 and hiv 2. my doctor just said you're good and then kind of abandoned me but the lab paper said naat is recommended for acute infections? I went to a std center , they did a rapid test for 1 and 2 and came back negative and they did hiv1 naat and that was negative as well but they mentioned that they don't offer hiv-2 naat and that its not fda approved. I then went and ordered a 4th gen test from another lab and that was negative.
 I'm really confused now and worst thing is since I was basically abandoned by my original doctor and didn't  have any access to an actual doctor I had to research the internet to find out what to do and really came across some scary things and articles talking about some subtypes and "circulating recombinant forms" and all those things that are really just so much information for someone such as myself. now I'm worried the first test was some how right and I got some rare kind of this already rare virus and the other three tests couldn't detect it? Unfortunately due to really struggling. emotionally and mentally I can't recognize if my fears and my need to keep getting tested over and over is warranted or if I should just take a deep breath and move on.

I'm a white female in California. my only risk factor was performing unprotected oral sex (no ejaculation) only one time on a Caucasian guy (American) who wasn't really in a risk group. I don't think he had ever travelled to Africa but he had lived in Japan for a while. 
btw as I was searching I also came across a post from someone else who also was going through this with bioplex. what do you think I should do right now? could this b
4 months ago
Sorry I forgot to add the risk of oral sex I mentioned was just one time and was 2 years ago and I have no risk exposures recently and also have never had any other type of sex.

could this be a test cross reaction or some weird thing because of bioplex?
Edward W. Hook M.D.
Edward W. Hook M.D.
4 months ago
Welcome to our four. Thanks for your question and your confidence in the information we provide. I’ll be glad to comment.   Let me start by saying that I am confident that you do not have HIV-2 and that your test results is falsely positive.  Let me provide some information to you about HIV-2 in the United States.

1.  HIV-2 is rare in the United States. Fewer than 50 cases are reported every year in the U.S.. The cases which occurred are typically in at risk persons who have traveled to West Africa or India.
2.  The exposure you describe, performing oral sex on a man, is an extraordinarily low risk activity for acquisition of HIV of any sort. Fellatio performed on a person with untreated HIV leads to infection on average less than once in every 10,000 exposures. Your partner sounds to be unlikely to even have HIV.
3.  Had you acquired HIV-2 more than a year ago, you would certainly have antibodies to the virus by the present time. The fact that you have had multiple additional negative tests ( the Bioflex follow up, the rapid test, the 4th generation test) which look for HIV-2 antibodies is strong evidence that your Bioflex result was falsely positive.

All laboratory tests have occasional false positive results. They are uncommon in currently use tests for HIV but they do occur. The burden of evidence related to your situation is that your positive test result was falsely positive. In my professional opinion you do not need further testing and can write this results off as a laboratory test error.  If you do want to seek further not testing, there are now large commercial laboratory tests which will perform HIV-2 NAAT tests.  Your healthcare provider can arrange to have such a test performed by speaking with her or his laboratory.

Again, I’m sorry you’re having to go through the anxiety and concern that falsely positive tests can cause. I hope the information I have provided is helpful to you. If there are further questions or anything is unclear please feel free to use your Upton to follow up questions for clarification. EWH
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4 months ago
Thank you. Dr. Hook

So in your opinion it's safe if I don't do any more testing? I feel that I'm becoming a bit obsessive about this and For some reason the Hiv-2 naat does scare me a bit since it's not fda approved and with covid going on. I also have one more question for you,  I accidentally came across an article talking about a circulating recombinant of hiv-2  and of course as a non-scientist that really scares me, do 4th gen assays that were built before the recombinant showed up able to detect these?

Best
Edward W. Hook M.D.
Edward W. Hook M.D.
4 months ago

I am confident, based on the testing you have already had that you do not have HIV-2 and that your positive Bioflex screening test was a false positive test.  I see no medical or scientific reason for additional testing. 

Recombinant HIV-2 infections would be detected by the testing you have had.

I sense as well that you've been on the internet working to learn more about testing, about HIV-2, etc.  I urge you to not go to the internet for information.  All too much of what is there is out of date, taken out of context, misinterpreted or just plain wrong and it is hard to tell the good information from the bad.  Please stay off the internet.  It will only increase you anxiety.  EWH


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4 months ago
Thank you Dr.Hook

I'm definitely trying to stay off the net now but unfortunately the damages is done from the previous months of me having to study and figure out what I need to do. It seems like different 4th generation tests have different sensitivity for hiv-2 or other subtypes. Does this difference matter after seroconversion has occurred? basically if say 2 years have passed by, any 4th generation test would be able to detect the antibodies even if rare, correct?

Best
Edward W. Hook M.D.
Edward W. Hook M.D.
4 months ago
Two years following acquisition of HIV-2 all 4th generation tests for HIV would accurately diagnosis infection if present.  Concerns about the impact of HIV-2 strain to strain variation on test performance are a great example of how internet misinformation can create unwarranted concerns.

I urge you to accept that you had the bad luck to have a false positive test.

We provide up to three responses to each question.  This is my 3 rd response.  Therefore this thread will be closed shortly without further replies.  Take care.  Please don’t worry.  EWH 
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