Zusatzfrage zu: HIV-1 / 2 antibodies and HIV-1 p24-AG test

Hello Doctor
Thank you for your competent answer. The answer for me was very helpful.

I have a supplementary question:
Is it standard to say in America or England: The test is safe after 4 weeks.
In which countries is tested that way (4 weeks)
As our doctors still say 12 weeks.

Why the difference?
There are many cases in which 4 weeks were too short and the result changed later (%)?

Thank you.

[Edward W Hook, MD]

I am not sure which country you are from but worldwide,  a negative HIV p24 antigen and negative HIV antibody test at 4 weeks is proof that you do not have HIV.  

The 12 week recommendation reflects tests that test only for antibodies alone, not antibodies and the p24 antigen and  is out of date.  The traditional and most widely used tests for HIV are tests for antibodies to HIV which are available both as so-called "rapid" or point of care tests which can be done in the clinic and laboratory based antibody tests. For all practical purposes both of these types of test perform comparably and provide accurate information on the presence or absence of HIV infection in virtually everyone at 8 weeks following exposure.  The recommendations for testing at 3 and even 6 months are the result of two factors- data from older tests no longer used (you really do not need to worry about which generation of tests you were tested with, at this time virtually all tests are far more sensitive that they were even 2-3 years ago when the 3 month recommendation was made) and secondly, the fact that some, mostly governmental agencies which have to provide recommendations for virtually everyone without the sort of interactions such as those you get with your doctor or on personalized sites such as this one, feel they cannot "afford" to be wrong and therefore make recommendations and guidelines which leave most people unnecessarily nervous for 4-6 weeks longer than the 6-8 weeks it takes virtually everyone to develop HIV antibodies.   When the HIV p24 antigen is added to the antibody tests, definitive answers are available even sooner - at 4 weeks.  

Hope this helps.  EWH

[mmmm79]

hello doctor
Thanks for your answer.
I have the test (HIV-1 / 2 AK + HIV-1 p24 AG) made in
Switzerland after 36 days.
If I understand correctly, you can say:
A test "HIV-1 / 2 AK + HIV-1 p24 AG" after 4 weeks
just as surely, as a simple test HIV-1 / 2 Antibody
after 8 or after 12 weeks?

thank you

[Edward W Hook, MD]

Correct.  Believe your test results. EWH

[mmmm79]

Dear Doctor

Thank you very much for you competent answers.
It calms me extremely.

I still have two final questions for me to calm down.

Do you work well "in practice or research" or
They work mainly as an online expert?

Have you or your colleagues ever heard of cases in
the DUOTEST (Hiv1/2ab and Hiv-1p24 ag) after 4 or 5
weeks was false negative and after the test comes positive? if so
are thre many cases? %

Please answer this last question. its importent for me to make finish with this problem.
I had a negativ test  (Hiv1/2ab and Hiv-1p24 ag) after 5 weeks and i can not be sure..( for me)

I would be grateful to them for answering these questions

Thank you very much

[mmmm79]

sorry
In your opinion, can i have sex with my girlfriend without condom
after  my negative test result ( 5weeks duo-test) ?

thanks

[Edward W Hook, MD]

I regularly see patients and do research as well as answer questions on line.

Your "have you ever" question serves no purpose. As I said, the available research states that you can be completely confident in the 4 week DUO test results.  

Yes, you can have sex with your GF without a condom and be confident that you did not get HIV from the encounter you described.  EWH

[mmmm79]

Dear Docotors

This question is really very important to me.
I hope you can answer me or help me ...

Are there cases in which an "HIV-1 / 2 AB with HIV-1 p24-AG" (DUO-test) after 4 or 5 weeks was false negative. And later (after 4 or 5 weeks) the test was positive. (Always under "normaly" conditions; no symptoms, no PEP, etc.

It must be possible to say whether such cases occur.
Whether you know  about a case Mr. Handfield or Mr Hook.

Many thanks and greetings

[Edward W Hook, MD]

You have ignored my last answer.  I will repeat it, pasting in the asnwer I gave you  ".... the available research states that you can be completely confident in the 4 week DUO test results."  

Please let me clarify an important point.  As a generalization for both you and other readers, you must realize that we VERY frequently get questions asking if different types of exposures or prevention measures are 100% effective.  The answer to that is that this is scientifically impossible.  For a variety of complex mathematical reasons far too complex to go into here, all one can do with well conducted scientific studies is estimate probabilities.  By definition, any estimate, cannot be 100% certain.  On the other hand, when Dr. Handsfield or I say that something is very close to no risk or of minimal risk, or use any other term to indicate a very small risk including "complete confidence", that means "close to zero" in a world where zero cannot be attained.  


This will end this thread.  EWH