I'd like to see papers describing the specific tests being used. Without that information we have no way of knowing what tests are being given. The reports that China in particular was producing as many as 7 false negatives before producing positive result for individuals clearly showing symptoms of covid-19 suggests the tests they were using (since they're not testing anymore, per reports out of China lately) were very specific, since tests for any coronavirus, or for exosomes which can be false positives for a broad spectrum of illnesses, would produce far too many positives instead.

There are specific tests I have read are used, antigen tests that reveal if the person has been exposed to SARS-cov-2 by looking for antibodies to it, or PCR tests, which seek viral RNA that is present in folks currently suffering multiplication of SARS-cov-2. I have not heard of an exosome test, or any others, however multiple tests of varying accuracy are in use today, and who is using what isn't commonly mentioned by any source.

Thanks!