I think you ask a fair question. Please allow me to give an analogy. The test used for heart attacks is troponin. In the evening thst there is troponin isoenzyme in the blood is is demonstrative of myocardial cellular death which is the definition of myocardial infarction
Troponin has become so sensitive that modest elevations diagnose MI but so sensitively that the question becomes how relevant is it. I would argue that the supercharged cycles of PCR assay are finding positive infections that are so minute that it is too sensitive a measure.
What is the definition of a case? Depends on whom you ask. An epidemiologist will tell you any person wirh a positive PCR is a case. This is the reason that medical testing is to be judicious and answer a question. The problem is we fell in the trap of allowing anyone to be tested at will. This does not paint a fair picture id the actual disease
I think a case should be defined as symptomatic with a positive test.
I think you are correct. Now this begs the question - are the numbers in this source where it says "number of new cases" - are these cases defined as symptomatic with a positive test or just positive test? This is an important distinction in order to get to the truth of the spread of COVID and to apply whatever protocols in order to deal with it in a positive manner.
“I think a case should be defined as symptomatic with a positive test.”
***************************************************************
And that was the definition used in the Phase 3 clinical trials.