Re: Ahhhh, keeping the myth of the “asymptomatic super-spreaders” alive!
You've got to test healthy people to keep the statistics working properly. Remember, there isn't an absolute 100% yes/no diagnostic, at least one that doesn't take an impractical length of time. So of the people you test you're going to discover four groups --positive and are sick, positive and are not sick, negative and sick, negative and not sick. This combined with general knowledge about the population in general will tell you what are the chances any individual will be infected. What those rather clever Greeks are up to is tweaking the probabilities based on experience in order to refine the test odds. Its very logical when you think about it but in our world of absolutes -- there is only blackest black and whitest white in the popular imagination -- the subtleties of what they're up to will escape most people.
(This 'refining on results' is what people used to call "Artificial Intelligence".)
Biting the hand that feeds IT
