Maybe there’s an overlap of “something” in the test...a piece related to something in their system. Did they do a full med analysis, i.e., ask about meds or drugs the people are taking which might effect the test. That seems way too many to me.
We will never know how many people are infected, just like we will never know about all the people who are infected with any other kind of "flu." Some people never present symptoms, or simply suffer through them.
The best we can do is valid statistical analysis, and we don't have enough data on COVIS-19 to do that yet.
All we have now is a collection of "fun facts," some of which may lead to truth. But it's impossible to know.
So decisions are a shot in the dark. And on top of that we have reporters who are too stupid to understand any of the science (or else they wouldn't be reporters).