[Question #7464] 4th Gen result conclusive?

5 months ago
Hi Doctor,

Today,I had a 4th Gen HIV 1&2 ABS+ P24AG test using the CMIA method(20 weeks after exposure). The test was one of 2 conducted from the same lab with the first being in october(12 weeks post exposure). The results for both were Non-reactive however i have noticed that value in the latest report has increased to 0.70 from 0.5.My Exposure was in july of this year so the window period  had passed by the time the first was done.
I have read on forums about delayed seroconversion and how that might give a false negative result.Since seeing the 0.7 value i have become extremely paranoid and feel like the world is slowly caving in on me. Also reading multiple sources and seeing that the 4th gen is 99.99% accurate at 12 weeks has made my mind jump into a frenzy thinking that i will be that 0.01% who even after these negative tests will test positive eventually.

My questions are as follows:
1: Could this be a case of delayed infection and thats why the the value has increased between the 1st and 2nd test?
2. If not delayed seroconversion,what could have caused the value to increase so greatly
3.Can i take my 20 week result as conclusive and that i am HIV-ve and move on or is there anything else to be worried/concerned about.
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
5 months ago
Welcome to the forum. Thanks for your question.

The world is not "caving in on" you, slowly or otherwise. It is 100% certain you do not have have HIV. Here are the details:

The AgAb HIV tests (including the one you had) are absolutely conclusive any time 6 weeks or more after the last possible exposure. Anyone advising "only" 99.9% accuracy is making a guess; there are no data to suggest anyone ever has tested negative more than 45 days after becoming infected, with the exception of those who were taking anti-HIV drugs that didn't prevent infection but delayed the positive test result. Further, it is a mistake to focus on the numerical value of a negative test. All results below the cut-off value (usually 0.9) are equally negative. In fact, the same specimen tested 10 times would give 10 different numbers, anywhere from 0.1 up to 0.9.

Those comments pretty well cover your three questions, but to assure no misunderstanding:

1. There is no such thing as "delayed infection".

2. I explained the test numbers. It's in the very nature of the test:  the number is not an indication of the amount of antibody present.

3. Your 20 week result is absolutely conclusive. There are NO reported cases, world wide, of anyone with the results you had that turned out to have HIV.

If you'd like to say anything about the nature of the exposure event you are concerned about, I might have further advice. But no matter how high risk it was, the test result rules. (This advice would be no different if your had mainlined HIV infected blood.)

I hope these comments are helpful. Let me know if anything isn't clear.

HHH, MD
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5 months ago
Hello doctor,

thank you for your response.

I apologise, in point 1 i meant to say 'delayed seroconversion' and not infection.

in regards, to the exposure it was with a csw however no penile penetration took place. Sextoys were used with condoms and fingering with gloves.
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
5 months ago
There is no such thing as "delayed seroconversion" with the AgAb test. The term "seroconversion" refers to antibody testing. The AgAb tests detect HIV antigen in additioin to antibody. If somehow antibody development were to be delayed, the antigen component of the test would still be positive -- indeed, even more strongly positive than otherwise. That's why the AgAb tests are superior to others and why they are always 100% reliable.

And in any case, you describe an exposure that carried little risk of HIV. If you had asked before testing, I would have recommended against testing. If it had been positive, it would have been necessary to explore other possible routes of infection. Probably nobody in the world ever caught HIV from the sort of event you describe!
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5 months ago
Hi doctor,
As this is the last of the follow up posts,
Apologies for missing this out earlier, but is feb I had vaginal sex(protected) and unprotected  oral female to male(I’m a male). 

Does the latest result discount this too?
In the hypothetical case that I take another test, can it turn positive under any circumstance?

H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
5 months ago
Don't overthink this -- it's very simple! Such test results overrule all exposures and all symptoms, no matter how risky at the time and no matter how typical the symptoms. There are no exceptions. You could have mainlined known HIV infected blood:  the test result proves you were not infected. Another test cannot be positve unless you have another exposure that infects you.

As you understand, that concludes this thread. I hope the discussion was helpful. Do your best to move on without worry!
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