85 new cases today in Scotland. Many people being diagnosed by symptoms/scans now. There's no capacity for mass testing. Or even NHS staff testing. Yet.
But sampling, & NHS testing, ARE being rolled out in Scotland.
S Korea and China did a bit better. But with bigger numbers and higher stakes.
Some small, very rich countries with advanced public health systems are doing quite a lot better. As you would expect.
Even if someone is disease free one day, they might not be the next day.
PCR looks for live viral genetic signatures from body fluids.
Immunology tests are needed for mass screening.
Unfortunately, those tests don't exist yet.
Hopefully they will soon.
Till then, shout out for your NHS. Working miracles with nothing.