[Question #9186] Hiv test window period

35 months ago

Dear Doctor

Regarding the window period for Hiv 4th generation test ag/ab.

You will find many different protocols and recommendations , so I’m confused some says 6 weeks is enough and any result after that is conclusive ?

Other recommended to repeat the test after 3 months for a conclusive and reliable result ?

And some says 6 months ?

I’m confused if i need to wait and repeat the test by 6 months again ? To have the 100% conclusive result or I don’t need that

Like can i negative result after 10 weeks change by 6 months ?

Edward W. Hook M.D.

35 months ago

Welcome to our forum. Thanks for your question. I’ll be glad to comment.

While the Internet and some overly conservative organizations suggest longer periods of time, results of fourth generation, combination HIV antigen/antibody tests are absolutely conclusive at any time more than six weeks following an exposure of concern. Actually, the scientific analysis of this issue suggests that the optimal time is 45 days but for all practical purposes the six week time works perfectly. FYI, at four weeks (28 days) results of fourth generation tests are more then 99% conclusive.

To be perfectly honest, neither of us has ever seen or heard of a patient who turned positive after a negative test at 28 days. While I am sure there may be a very small number of persons in whom tests turn positive at this later time point, that number is very, very low. You can have complete confidence in the -4th generation HIV test anytime more than four weeks after an exposure. Recommendations for longer periods of time are overly conservative and and only prolong the periods of uncertainty and anxiety without any scientific basis.

I hope this information perspective is helpful to you. EWH

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35 months ago

Thank you fro your reply Doctor

I did a 4th generation test by 4 months with negative result, and i did a hiv pcr test as well by 4 months with negative result.

Is that consider conclusive ?

Can the pcr test turn positive later ?

And should I repeat my hiv 4th

generation by 6 months to be sure about the result?

For a certain and 100% reliable result, is 3 months more than enough? Or 6 months ?

Thank you Doctor

35 months ago

And you mentioned there is very very low number need more than 6 weeks , is 3 months enough to cover all these people and give a conclusive result that you can be confident with ?

Edward W. Hook M.D.

35 months ago

PCR testing was a waste of time and money. A negative 4th generation test at any time more than six weeks after an exposure is entirely conclusive. Your negative test at 4 months is entirely conclusive and does not need to be repeated. Believe your results!!!

You misread my reply which indicated that a very, very small number of tests turn positive between 4 and 6 weeks.

Believe your test results. EWH

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35 months ago

So doctor to make it more clear for me please and understand it correctly. you meant by a very, very small number of tests turn positive, the meaning was for the who test negative by 4 weeks then turn positive after 6 weeks ?

You didn’t mean by the very, very small number of test turn positive, that they test negative by 6 weeks then turn positive by 3 months ?

Please if you help me with understanding that if which one it was, like can i negative result after the window period turn positive?

So my result at 4 months can’t change? I don’t need to worry more and I don’t need to have more test by 6 months?

All the best doctor

Appreciate your help

35 months ago

That was my last enquirers sir

appreciate everything and all the help

Thank you before your reply

Edward W. Hook M.D.

35 months ago

Sigh! What I said was that when persons have a negative test at four weeks only a very, very small proportion of those individuals go on to have positive test at a later time. This completes this thread. Take care. EWH---