Where do they get these numbers from?

I’d hate to contract the NoroVirus. It sounds really awful and those poor souls who were brought down by it in recent months have my sympathy. There were many: over the Christmas break I read somewhere that over a million people had been affected, and here’s the odd part: only around 4,000 had presented themselves for treatment but the Medical Authorities estmiated that for every one who had presented, there were over 260 that had not. I thought no more of it at the time.

And then today I read that in Scotland there have  2,824 recorded cases in recent weeks. However, according to the Health Protection Agency in England and Wales, for every one case that is reported, an estimated 288 are not.

Read that again: for every case reported 288 are not. Where does that number come from?

It is either incredibly well calculated to bring that level of accuracy or it is such a wild guess as to be incredulous. My money is on the latter.

But just as I read and moved on when I first heard this story, I find it sad that I cannot locate any stories in the media of anyone challenging the accuracy or source of this magic 288 multiple.

Where do they get these numbers from?