All that those tests do is check for specific RNA fragments
Found in SARS-CoV-2
However…
If an evil scientist with a box of CRISPR
Went to work on Yersinia pestis bacteria
The PLAGUE virus
It would not be too hard to insert DNA fragments
That would manufacture the SARS RNA fragments
Searched for in the test.
Then the cells under attack by the Black Death
Form exosomes
And eject foreign RNA fragments
Into the bloodstream or into the lungs
Along comes a swab
And a simple test that looks for one thing only
But, how do all the countries using anti-malaria drugs succeed
If plague bacteria are the culprit?
Because they add an antibiotic like Azithromycin or Doxycycline
Used to be that doctors would test for more than one thing
Nowadays they seem to be sure there can only be one
And so they find that one