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How do we determine the HIV window period?

I have a question that I could not find addressed anywhere online. I know that the window period for HIV testing is stated as being anywhere from 6 weeks to 6 months, with many places saying 3 months.

What I do not understand is, what kind of research/evidence is used to determine this? I recently called an HIV/AIDS hotline and they told me that the way of determining this information is by asking someone who has tested positive when their last exposure was, but is this really accurate? Most people who test positive for HIV probably have had numerous possible exposures.

For example, say Joe Schmo has had unprotected sex once a month for the year of 2007 (Jan-Dec). He gets tested at January 2008 and tests negative, he then tests again on March 2008 and tests positive. Under the current information we have, it would be logical to assume that he had acquired the virus somewhere between Nov-December. However, how do we really know this? How do we know that he has got HIV from a April 2007 exposure? --- I don't think we can, right?

In my opinion, the only real way to be sure of window periods would be to inject HIV-negative people and see how long it takes them to turn positive. Obviously this is not only illegal but its just plain wrong. So how do doctors, HIV specialists, scientists..etc. set a "window period"?

I hope I am mistaken about the methods that are used to determine the window period. Does anyone else have any information on the research done on determining window periods? If you do, it would really ease my mind. Thanks
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Avatar universal
3 months is the guidelines setup by the manufactures, FDA. They are the folks that say when their tests are approved to give a conclusive negative test result.
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Avatar universal
Accoding to the suggestions from the Doctors, 8 week (even 6 week) is good enough.
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480448 tn?1426948538
I'd like to add my two cents....

Like anything else in the medical world, suggestions/recommendations are based on decades of research, studying and looking at trends, etc......particularly with HIV?.... by examining the data surrounding the people who have tested positive/become infected.

Obviously, with HIV, there can not be any type of research studies, whereas people could be exposed to the virus, and studied closely until they develop antibodies.  The current window period is a conservative estimate based on how long it has taken people to test positive for the virus after the possible incident of exposure.

This is not a direct science, as you are dealing with many aspects of infomation gathering in a SUBJECTIVE manner......people giving accurate information, remembering correctly, being truthful, etc.  What is VERY telling, imo...is the fact the both doctors in the HIV forum here, as well as ID docs I have closely worked with through the years, as well as in my OWN work experiences, have NEVER seen a patient who tested negative at 6 weeks post possible exposure then test positive in the future.

Also, the people who have indeed tested positive, as a whole....have usually done so quite rapidly.  Therefore, organizations such as the CDC take a conservative stance for obvious reasons.  Meaning...just say (hypothetically) that the subjective research shows that the average period of time that it takes for a person to develop antibodies is 6-8 weeks, it is only responsible to extend that period to allow for any special circumstance, including perhaps multiple exposures, people not remembering correctly, differing viral load exposures, etc.....so that a person can be confident in their results...knowing that at 3 months....they can be SURE that their test results are conclusive either way.

It's really common sense.  ANY recommendation coming from the medical community will always be conservative in nature, for obvious reasons.  If YOU personally have had a negative result at 3 months, then you are in the clear.

Why you are splitting hairs in this situation is confusing.  You say it is for forum users to be educated.  All of the data from the docs here in the expert forum, as well as from forum users with quite a bit of either personal or professional experience in the field is all over the place on medhelp.....it seems pretty cut and dry to me.  This is a forum dedicated to users who feel they may have had an exposure and want to guage their risks.  You've done that thoroughly.  With all due respect...this isn't a forum for discussing WHY the recommendations are what they are.  If you doubt the recommendations, the only thing you could do is spend more time, energy and money testing past the 3 month period.

But, that unfortunately is a doule-edged sword.  Because, when you are dealing with anxiety-driven concerns...when is it sufficient?  If you have doubts that 3 months is an ample amount of time to cover the window period....then at what point will YOU personally be satisfied that your results are conclusive?  See the problem?

For me....the data out there is about as reassuring as it can be.  And, the title of your post is "how do WE determine the window period"?  "WE" don't.  Agencies like the CDC determines those, and we, as consumers have to have faith in those agencies at some point.  The only thing left for you to do to ease your mind about the window period is contact the CDC directly and ask for information on what methods were used to determine the window testing period.  If they forwarded you a 1000 page dissertation with that information...would THAT be enough to ease your mind?  These are questions for yourself...as you need to be seriously honest with yourself, so that you can recognize anxiety/phobic behavior that is worsening or developing.

So, hopefully you can see where happydaze is coming from...you are, bottom line....asking the wrong people.  WE didn't develop the window period, we are just educated enough through experience to know that it is acurate enough that you can move on with a neg at 3 months.  Beyond that...for this particular topic, unless there is a CDC employee posting here, we can't really answer this question to your satisfaction.

In my personal opinion, and with all due respect.....I strongly feel that you are simply fueling your anxiety by overthinking all of these issues, and you owe it to yourself to perhaps start addressing that anxiety...rather than to continue to ruminate about HIV-- which is clearly not a concern from you. Anxiety can wreak havoc on your life...and if you don't start dealing with it NOW, you will spend a lot of time and grief trying to bring it under control.  TRUST me, I speak from experience.  I have a lifetime long history of anxiety issues....and it is a horrid cycle.

Best of luck...I hope you can find the peace you need.
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Avatar universal
I am not trying to start arguments, I am trying to respond to your specific issue.  Your post indicates that you want your mind eased.  I submit that with a negative test result three months out, you should not need any more to ease your mind.   This smacks of OCD and a need for handholding.  As far as I am concerned, you have repeatedly been given full responses relative to risk and testing. Since you cannot seem to accept your conclusive negative results and now seek to question the science behind CDC and Abbott Laboratories' determination that 3 months is conclusive, then I think this board has gone as far as it can to provide you with information within its scope.  Thus, I respectfully withdraw from this conversation.  
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Avatar universal
3 months is conclusive PERIOD.
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Avatar universal
The purpose of this forum is to help each other by answering questions, not to start arguments. I have a legitimate question. I simply want to know what kind of research has been done on the topic above and if you do not have the answer, I'd appreciate it if you would just not reply and let someone else who might have the information answer instead.  Thanks

With that said, does anyone else have an answer to my question? I'd really appreciate it. Thank you
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Avatar universal
What does it matter?  If you are still posting on your particular issue in which you tested negative 3 months after your exposure, then you need to MOVE ON.  You are conclusively negative.  Understanding how Abbott Laboratories and the CDC established that timeframe is not going to change that you are negative. Really.

If you are wanting to know the scientifc "methods" in which Abbott Laboratories and The CDC have used to determine that 3 months is the timeframe for conclusive results, then you need to go to those entities to find out the "methods" they used to make that determination.    It's as if you want someone on this site to prove to you that you are in deed negative after your 3 months test.  We're not here to do that.  Your questions about your exposure and conclusivity of your results were answered.  Post your question to the docs (including thta you tested 3 months after your exposure) and see the response you are likely to get.  Honestly dude, you are chasing windmills.  You're really much better off letting it go and believing your test results.  
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Avatar universal
Thanks for your reply. However, my question was regarding the methods to which the window period is determined. Your answers were regarding the length of the window period.

If anyone has any information on the methods in which HIV experts determine the window period, please comment. Thank you
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Avatar universal
By the way, from your last thread you asked a question about your specifc situation and Teak advised the following which answers your questions and you should follow:

Oraquick Advance is very accurate at 3 months post exposure.  False negatives are because the test is done too early and the tester did not follow the proper guidelines. Any test not done at the proper time can give false negative results and any test is capable of giving a false positive, hence the reason for confirmative testing.
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Avatar universal
The window period is not 6 months.  The window period for the current generation of diagnostic tests is 3 months. Infections in most people will be detected in six weeks, but the manufacturers of the tests and specialists will indicate that a test is not conclusive until 3 months after the exposure.  Bottomline, if you test negative, that result is conclusive for any activities that occurred within 3 months or more of that test.  If the exposure is less than three months, then the test result it is not necessarily conclusive.  You want to start narrowing down to days and weeks and I submit that you cannot do so with any degree of accuracy.   If your exposure was six weeks from your test, well the results are a good indication, but not conclusive.  Bottomline, three months is the window period and the manufacturers of the tests identify and publish the window periods.  If you want to know why from a scientific perspective, you'll need to go to them.
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