can P24 antigen & Hiv antibody Be taken on the 20th Day?

can P24 antigen & Hiv antibody Be taken on the 20th Day? and how reliable the result?
thanks so much for comments

[dmn777]

The antigen part would likely be reactive for healthy immune systems from day 16 maybe a little earlier. The result would be a good indicator. Obviously have a confirmatory on 3 months.

[Teak]

What was your exposure?

[dell1420]

thanks for your comment dmn777,
so you mean that the antigen will active from the day 16th then the test can detect them? how about the antibody?
I'm still so worry....

[dell1420]

hi Mr Teak.
I made love with a woman who I don't know the HIV status. THe stupid thing is that I didn't check the condom whether it was broken or not.
I just want ask you guys about the antibodies and P24 antigen in the day 20th  is good enough? Can u guys explain me more about it.

Thanks so much.

[Teak]

Had the condom failed you would have known without a doubt. Had you had an exposure your test would be conclusive 3 months post exposure. You do not need testing.

[dmn777]

Well here in Ireland an antigen/antibody test is performed routinely at 28 days. Antigens are produced before antibodies and so naturally the p24 part (antigen part) of the test will become reactive sooner than the antibody part. Antigen production in healthy immune systems starts around day 10 and peaks at day 16. After which the antigen levels drop and antibodies become detectable. A HIV DUO test (antigen / antibody) will detect one or the other at 28 days. At 20 days the antigen part should be reactive and this would be a good indicator of your status. Test again at 28 days just to be sure. You will likely be fine, for the most part it sounds as though you have had safe sex.


The guidelines on here say a confirmatory at 3 months is recommended. Your doctor may advise differently in your country.

[Teak]

Antigen testing will not tell you if you are infected or not.

[dell1420]

many thanks for your comment dmn777

tomorrow is my 26th day from the day I had sex. I just can't wait more to have a test. Do you think it is ok to have another DUO test ?
....very worry

[dmn777]

Some of us in other countries have varying opinions on this. DUO tests are available for a reason.

[dell1420]

thanks dmn777

just to clarify, you mean that the test on the 20th day is only true for the P24 antigen detective, not for the antibodies as there are not enough of antibodies to detect?

[dmn777]

I understand you are very anxious. Its up to you, the result at 26 days is unlikely to differ at 28. Antigen production peaks at 16, antibody at day 25 on average. You would have a pretty good chance at detection.

Although me an Teak differ on some subjects, we agree that your risk was minimal to begin with. Try to relax :)

[dmn777]

Refer to my last post. There will be no antibody production without antigen production.

[dell1420]

Thanks for all your helps. I really appreciate.

[dell1420]

hi Teak,

Could you explain me more why the antigen testing "will not tell you if you are infected or not" ? I'm in confusion...

[Vance2335]

Antigen tests while help look for an infection early can not always be found. That is why the antigen test is not a diagnostic test and an antibody test is. Yes antigens are produced 1st before antibodies but the test many not fnd them due to a time frame. Another reason why an antibody test is the only diagnostic test.

But better then any of that info is as you have been told...YOU HAD NO RISK.

[dmn777]

Ok, there seems to be a bit of confusion here. Firstly the DUO test is a diagnostic test (antigen+antibody). Secondly with regards to time frame, the test is sensitive until antigen production drops off, generally 3 weeks post exposure. By that time the antibody part will be reactive.

[Teak]

3 months is when a person can get a conclusive negative test result.

[dmn777]

Your FDA finally approved the HIV DUO test for use in June of this year.

[Teak]

The DUO test approved in June 18th 2010 is conclusive at 3 months post exposure.

[Vance2335]

The antibody part is but not the antigen part of the test. If someone tests positive for antigen it is not considered a positive HIV test until it can be confirmed with an antibody test and a WB.

Yes when it drops off...around 3 weeks but that is a variable number and is not hard and fast.

[Teak]

http://www.fda.gov/downloads/BiologicsBloodVaccines/BloodBloodProducts/ApprovedProducts/LicensedProductsBLAs/BloodDonorScreening/InfectiousDisease/UCM216309.pdf

LIMITATIONS OF THE PROCEDURE

A test result that is nonreactive does not exclude the possibility of exposure to or infection with HIV-1 and/or HIV-2. Nonreactive results in this assay for individuals with prior exposure to HIV-1 and/or HIV-2 may be due to antigen and antibody levels that are below the limit of detection of this assay.

[Teak]

UK is the same as the US.

Post-test discussion

The need for a repeat HIV test if still within the window period after a specific exposure should be discussed. Although fourth generation tests shorten the time from exposure to seroconversion a repeat test at three months is still recommended to definitively exclude HIV infection.

http://www.bhiva.org/documents/Guidelines/Testing/GlinesHIVTest08.pdf

[dmn777]

http://www.medhelp.org/posts/HIV-Prevention/HIV-Duo-Test----28-Day-Test/show/255682

Have a good read.

[Teak]

Oral sex never transmits HIV.

[Teak]

by Emily_MHModerator , May 06, 2010 07:28AM


On MedHelp, we follow the guidelines set by the Centers for Disease Control (CDC), test manufacturers, FDA, and our experts, Drs. HHH and Hook.

For this forum, it is 3 months. Yes, a 6 or 8 week test may be accurate, but it's not conclusive until 3 months. Saying that the 6 or 8 week test is a good indicator is fine, but to be conclusive, testing must happen at 3 months. It is also this forum's position that oral sex by itself does not require testing.

You can quote doctors, but make sure you say that. Doctors are licensed to practice medicine and can say that given the particulars about exposure, timing, etc., that someone doesn't need more testing. However, unless you are a doctor, you can't say that.

Emily
MedHelp

[vovo82]

my Sister is pregnant and the results state that P24 antigen is reactive and then there is a comment below say "positive p24 antigen confirms hiv infection on the infant" Does this mean the child is hiv positive?

[Teak]

No and you don't diagnose HIV with P24 tests.