During all 4 epidemics prior to COVID-19 since 2000, CDC & WHO were concerned about the high false-positive rates for PCR tests & issued guidelines to try and minimize them
But for C19, both somehow forgot all about PCR false-positive rates.
Diagnosing COVID-19 infection: the danger of over-reliance on positive test results,
The evidence shows that false positive PCR results are common enough to impact clinical and policy decisions.
Here is the original source of that abstract . . .
The random thoughts of 99th Monkey . . . an occasional rant and other reflections in the hall of mirrors.