Coronavirus: Are the Coronavirus tests such a big deal?

Over the last few weeks, the news is all about Coronavirus tests.

This is great if, they are 100% accurate.

But if they are not, are they any use?

Even if they are 99.9% accurate, in a population of 66 million (I think that is the size of the UK), that would mean many would get incorrect results.

It could mean that someone is told they have had the Coronavirus when they have not, then get it, and spread it around.

If a nurse or doctor is told they have had it, when they have not, they could be putting themselves at great risk, and if they get it, spread it to many patients.

On the other hand they may be told they have never had it, when they have, and so stay in isolation. So a nurse or doctor, who could be helping people, is at home.

So the question will be, is how accurate will these tests be, and how much error will we deem to be acceptable?