"Detection of severe acute respiratory syndrome coronavirus 2 ribonucleic acid (SARS-CoV-2 RNA) in a clinical specimen using a molecular amplification detection test."
The test referred to is the PCR. And as you can plainly see, it is detecting, not the virus itself, but a piece of RNA.
A piece of RNA ASSUMED to come from the virus, SARS-CoV-2.
I say ASSUMED because, where is the actual virus? Where is the virus isolated from all surrounding material?
If you don't have the virus, you can't say, with any degree of certainty at all, that you have a piece of it (the RNA).