I ask because I have seen the definition of a case as such: "An instance of disease with its attendant circumstances." If you don't have attendant circumstances and just a positive test result do you actually have a case?
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.