This is an attempt for now just to organize thoughts about. about interpreting virological tests. One could picture it in some ways as applicable to medical testing sought in the clinic more generally.
Virological tests are typically interpreted either based on number of confirmed cases. or 1% positivity. These two numbers can be seen as emergent. Processes include the dynamical spread of disease. as well as any factors that drive testing among people who are virologically positive. more people who are virologically negative. possibly also worth thinking about people who do have clinically relevant exposure to the virus. but are not in the right time window to test positive. This is a class we could definitely consider distinguishing from the straight false positives and false negatives.
Our framing question can be... What do we think if the number of confirmed cases goes up at the same time that positivity goes down? Our simplest guess would be a scare based on a true... would be a scare of some kind. True cases might be going up or down, but they are not probably the main thing driving an increased demand for testing.
Covid draft, there must be more. https://docs.google.com/document/d/1ZQ3zKlmQ4ADEF69J0w0LIviId2_rLUD0zqz6RjqW0As/edit?tab=t.0