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DUO test question
Hi,
Before stating my question, i would like to mention that i am aware of your stance when it comes to testing. Only a test at 13 weeks or beyond is conclusive. The only purpose of my question is to obtain more insight from people who have experience with HIV about HIV tests.
I have a question about the DUO tests. These tests can detect both antigens and antibodies. Antigens appear first in the body, reach very high levels and then start to decline in numbers. At the same time, antibodies are produced by the body (leading to the actual decrease of the antigens). Both antigens and antibodies should exist in sufficient quantities (regardless how low these quantities are) to be detected by the test.
My question is the following. Would there exist a period, after the antigens have peaked, that the antigens become too low to be detectable while at the same time the antibodies did manage to become enough to be detctable either? In other words, is there a period where both antigens and antibodies are too low to be detectable (given that antigens have peaked)? If so, how long can this period be? longer than 2 weeks?
Many thanks!
Before stating my question, i would like to mention that i am aware of your stance when it comes to testing. Only a test at 13 weeks or beyond is conclusive. The only purpose of my question is to obtain more insight from people who have experience with HIV about HIV tests.
I have a question about the DUO tests. These tests can detect both antigens and antibodies. Antigens appear first in the body, reach very high levels and then start to decline in numbers. At the same time, antibodies are produced by the body (leading to the actual decrease of the antigens). Both antigens and antibodies should exist in sufficient quantities (regardless how low these quantities are) to be detected by the test.
My question is the following. Would there exist a period, after the antigens have peaked, that the antigens become too low to be detectable while at the same time the antibodies did manage to become enough to be detctable either? In other words, is there a period where both antigens and antibodies are too low to be detectable (given that antigens have peaked)? If so, how long can this period be? longer than 2 weeks?
Many thanks!
Hi there -
Our members are not doctors, and therefore can not state something other than what the test manufacturers say. Our experts on MedHelp have all worked with patients, and some still do. Those that don't currently work with patients work in research.
I hope this helps.
Emily
Our members are not doctors, and therefore can not state something other than what the test manufacturers say. Our experts on MedHelp have all worked with patients, and some still do. Those that don't currently work with patients work in research.
I hope this helps.
Emily
Antigen tests are not standalone tesst and not approved for diagnosing primary HIV infection. Antigen tests are supplemental tests used in conjunction with antibody tests.
dear teak
4 weeks max for the antigen test and 3 months max period for the antibody test ?
but antijen test still not approved at 4 weeks ?100 percent?
4 weeks max for the antigen test and 3 months max period for the antibody test ?
but antijen test still not approved at 4 weeks ?100 percent?
An antigen test is good from week 1-4, an antibody test is good from week 4-3 months post exposure.
I have wrote many disclaimers that i completely understand and respect that you follow the CDC guidelines. Unfortunately it does not seem that you are reading my question. My question is not about the conclusiveness date of the DUO (i know the opinion of different forums/doctors/organizations about it), but about the period of time where both antigens and antibodies are below a detectable threshold.
Is is true p24 antijen test only good after 4 weeks not very accure after6 weeks ??
OFFICIAL guidelines in France for HIV testing.
THE ORIGINAL TEXT IN FRENCH:
Une personne peut être considérée comme non infectée par le VIH si le test de dépistage Elisa combiné est négatif six semaines après l’exposition supposée au VIH, et non plus trois mois comme auparavant.
ENGLISH TRANSLATION:
A person can be considered as not infected with HIV if the Elisa combined (i.e. DUO) test is negative six weeks after suspected exposure to HIV, and not three months as before.
THE ORIGINAL TEXT IN FRENCH:
Une personne peut être considérée comme non infectée par le VIH si le test de dépistage Elisa combiné est négatif six semaines après l’exposition supposée au VIH, et non plus trois mois comme auparavant.
ENGLISH TRANSLATION:
A person can be considered as not infected with HIV if the Elisa combined (i.e. DUO) test is negative six weeks after suspected exposure to HIV, and not three months as before.
No that isn't what it means at all, it means a conclusive negative test result is conclusive at 3 months the 3 months have nothing to do with a postive results.
I agree and that is sad. Of course people should be on the safe side when taking a HIV test. The consequences of a false negative are much more devestating than those of a false positive. However, HIV testing is based on science, which progresses all the time. However, giving different window periods for the same type of test, and also stating different infection risks for the same type of activity is far from science.
Teak,
I agree that in the UK, the official guidelines are that a test at 3 months is recommended even for a DUO (regardless of how positive (no pun intended) indication a 28-day test gives).
On the other hand, the official window period in France is 6 weeks. These guidelines are from HAS (which stands for Haute Autorité de Santé, which translates into the High Authority of Health).
Again, i am not trying in any way to criticize whatever window period is used on this website as you explicitely state that you follow the CDC guidelines when it comes to this. I was simply trying to get input on a scientific question.
I agree that in the UK, the official guidelines are that a test at 3 months is recommended even for a DUO (regardless of how positive (no pun intended) indication a 28-day test gives).
On the other hand, the official window period in France is 6 weeks. These guidelines are from HAS (which stands for Haute Autorité de Santé, which translates into the High Authority of Health).
Again, i am not trying in any way to criticize whatever window period is used on this website as you explicitely state that you follow the CDC guidelines when it comes to this. I was simply trying to get input on a scientific question.
http://www.cdc.gov/globalaids/Resources/pmtct-care/docs/TM/Module_6TM.pdf
Page 11
#4
In an adult, a positive HIV antibody test result means that the person is infected, a person with a negative or inconclusive result may be in the “window for 4 to 6 weeks but occasionally up to 3 months after HIV exposure. Persons at high risk who initially test negative should be retested 3 months after exposure to confirm results
UK Fourth Generation Testing
http://www.bhiva.org/documents/Guidelines/Testing/GlinesHIVTest08.pdf
Post testing
Page 11
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.
Page 11
#4
In an adult, a positive HIV antibody test result means that the person is infected, a person with a negative or inconclusive result may be in the “window for 4 to 6 weeks but occasionally up to 3 months after HIV exposure. Persons at high risk who initially test negative should be retested 3 months after exposure to confirm results
UK Fourth Generation Testing
http://www.bhiva.org/documents/Guidelines/Testing/GlinesHIVTest08.pdf
Post testing
Page 11
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.
I agree totally and lets not even mention these lovely internet sites that just confuse the hell out of people,if you look at the dates around 90% of those sites are all outdated.I can,t believe they are still talking about some nurse that seroconverted after 9 months.That happened 20 years ago for god's sake.It's 2011 now.We need to move on and respect the modern 4th generation tests avaliable to us now.
true...
another confusing point is that many here quote the doctors when it comes to oral sex but believe they (i.e. the doctors) don't work with patients in order to have a reliable opinion about the window period (as the doctors refer to 4-6 weeks being conclusive)...
if the people posting here are conserative with their opinions when it comes to both window period and oral sex (i.e. like the CDC), then i would have understood... but to be conservative with the window period and not with oral sex is a bit hard to understand (not that i believe that oral sex is risky, but just as a matter of principle)
another confusing point is that many here quote the doctors when it comes to oral sex but believe they (i.e. the doctors) don't work with patients in order to have a reliable opinion about the window period (as the doctors refer to 4-6 weeks being conclusive)...
if the people posting here are conserative with their opinions when it comes to both window period and oral sex (i.e. like the CDC), then i would have understood... but to be conservative with the window period and not with oral sex is a bit hard to understand (not that i believe that oral sex is risky, but just as a matter of principle)
I know and i am just as confused but i have always believed that the CDC and the FDA are ultra conservative.Read the expert doctors forum and see what they say about the window period and they have been involved with Hiv matters since day dot.I'll tell you want the problem is,you get one diamond in the rough that seroconverts past 3 months out of literally millions and all of a sudden it's panic stations when in all reality these situations are as rare as hens teeth.
yeah that was my impression after reading this and other forums.
what just confuses me is that on this forum, they follow the CDC guidelines for window period; but on the other hand, they do not follow their guidelines when it comes to oral sex!
and i don't think i'm the only person confused about that, especially with the lack of motivation to this behavior and the one-line answers of 'oral is no risk' and 'conslusive answer at 3 months'...
what just confuses me is that on this forum, they follow the CDC guidelines for window period; but on the other hand, they do not follow their guidelines when it comes to oral sex!
and i don't think i'm the only person confused about that, especially with the lack of motivation to this behavior and the one-line answers of 'oral is no risk' and 'conslusive answer at 3 months'...
You will find many Hiv experts that will tell you that a DUO/Combo is conclusive at 4 weeks because that is when the p24 antigen peaks.However the CDC and FDA and the manufactures of the tests will continue to say 3 Months as the official guideline.
I completely agree about the different guidelines, and this is why i formulated my question in a different way to avoid someone just replying that e.g. the CDC guidleines are 12 weeks etc.
I was more checking if someone has read any articles that discuss this 'seconday window period' of DUO tests, and whether such a window period still exists now that these tests have been available for about a decade (i.e. that they have improved sensitivity).
I was more checking if someone has read any articles that discuss this 'seconday window period' of DUO tests, and whether such a window period still exists now that these tests have been available for about a decade (i.e. that they have improved sensitivity).
Well then go with that.Each country has different guidelines,Here is some clinics in sydney,Australia if you have tested negative at 6 weeks with a p24 combo/Duo they will refuse to test you again.That's their policy.
Thanks for the answer.
I know the stand of 'freedom health' on the window period issue.
However, in France, they say that 6 weeks is conclusive, period. No need for a test at 12 weeks, not even for peace of mind or anything similar.
I know the stand of 'freedom health' on the window period issue.
However, in France, they say that 6 weeks is conclusive, period. No need for a test at 12 weeks, not even for peace of mind or anything similar.
From freedom health--A person should not have to wait 12 weeks to test and should be offered a DUO test at 4 weeks instead.Now having read that the DUO should be an option for anyone who is extremely stressed and anxious.Of course it must be followed up by a final test at 12 weeks but a negative DUO at 4 weeks would present a very reliable result.I hope this helps you Peterslm.
Hi Teak,
That wasn't exactly my question and i even stated a disclaimer in my question about the 13-week rule.
Although the 3 months post exposure is more of an international guidelines for most of the countries (and it is the CDC guidelines that you follow on this forum [although the oral sex recommendation of CDC is not followed]), there are some countries who have explicitely stated a different window period. One example is France who has a window period of 6 weeks.
THE ORIGINAL TEXT IN FRENCH:
Une personne peut être considérée comme non infectée par le VIH si le test de dépistage Elisa combiné est négatif six semaines après l’exposition supposée au VIH, et non plus trois mois comme auparavant.
ENGLISH TRANSLATION:
A person can be consider as not infected with HIV if the Elisa combined (i.e. DUO) test is negative six weeks after suspected exposure to HIV, and not three months as before.
Anyway, my sole point from posting this about the window period is not to have yet another thread about 6 weeks vs 3 months for DUO. It is simply to show that my answer is legitimate and deserves a bit more than a copy-paste of the 3 months post exposure conclusiveness.
I completely understand that you follow the CDC guidelines here for the window period but maybe there are some who are not bound to these guidelines can share their knowledge/experience?
That wasn't exactly my question and i even stated a disclaimer in my question about the 13-week rule.
Although the 3 months post exposure is more of an international guidelines for most of the countries (and it is the CDC guidelines that you follow on this forum [although the oral sex recommendation of CDC is not followed]), there are some countries who have explicitely stated a different window period. One example is France who has a window period of 6 weeks.
THE ORIGINAL TEXT IN FRENCH:
Une personne peut être considérée comme non infectée par le VIH si le test de dépistage Elisa combiné est négatif six semaines après l’exposition supposée au VIH, et non plus trois mois comme auparavant.
ENGLISH TRANSLATION:
A person can be consider as not infected with HIV if the Elisa combined (i.e. DUO) test is negative six weeks after suspected exposure to HIV, and not three months as before.
Anyway, my sole point from posting this about the window period is not to have yet another thread about 6 weeks vs 3 months for DUO. It is simply to show that my answer is legitimate and deserves a bit more than a copy-paste of the 3 months post exposure conclusiveness.
I completely understand that you follow the CDC guidelines here for the window period but maybe there are some who are not bound to these guidelines can share their knowledge/experience?
The DUO test is not approved to give a conclusive negative test result earlier than 3 months post exposure.
Is High Reliability for 4weeks.
do u have a expose?
do u have a expose?
Thanks for the answer freylim but my question was neither about the reliability of the DUO at 4 weeks nor about the conclusiveness of a test being at 12/13 weeks.
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