Question
Why different sites give different 'window' periods for HIV tests?
5 December 2008. Related: All topics, HIV testing, HIV transmission.
Why do some sites say that it takes up to 12 months for the virus to be detected in HIV tests and most say 3 months, 6 tops?
Answer
Different texts have been written at different time and some sites are not updated very often. Hence the differing information.
In addition, some writers are more conservative and traditional. There was only one documented case when a person seroconverted only after almost a year after the infection. That is why many sites would take the 100% sure stance and may say a year. The truth is that when that case happened, it was years ago and the modern test systems were not available. Nowadays the results are reliable and are received way quicker than that. There is detailed information about testing and the different types of test here.