My guess as to why there is little information about window period is that, after thinking about it, it must be a very difficult to find people with a definate exposure date and give them weekly serial tests out to 6 months or one year. Even if they did find 20 or 50 such people (HCW or rape victems, etc) it is still only a handful of people and may not be truly representative of the results of millions of people.

The only way to truly do this would be to infect 1000 volunteers with diverse ages and backgrounds and races and test them for one year. So this type of study is out of the question. Do we see a show of hands for volunteers?

So, once I thought the 6 month window period as being stupid. After thinking about it this way I'm now thinking that the CDC knows that 99% of people will test positive by 3 months. ANd that the other .5% will test postive in month 4 or 5 and the remaining .5% will be outliners like the infamous 13 month man and the "FUO" guy. So the conservative, nervewracking as it is, 6 month test will catch a small handful of patients may be worth it.

If you think about it even .5% of 100,000 people is 500 people! It is important to catch them. 500 people spreading it to another 500 or 1000 people can have a profound impact on an epidemic. So, even though it is a statistically small number on a personal level. It can have a huge impact on a national level on the epidemic. I wrote a small computer program to simulate the impact of not catching those few who produce antibodies in month 4 and 5 (I know I need a life!) and over 5 years or a decade it has a HUGE impact. It was a another 75,000 to 125,000 infections.

So unless the gold standard moves to PCR testing the 6 month test makes sense from "the big picture" perspective.

Does my "take" make sense to you?

No argument here. MH