One problem with this is that in the early stages of the spread you would have to run hundreds of thousands of tests daily in order to get statistically signifi

One problem with this is that in the early stages of the spread you would have to run hundreds of thousands of tests daily in order to get statistically significant results. This is clearly impossible with the available lab infrastructure. And this is ignoring the possibility of getting false positives. Maybe it will be possible to get quantitative results with fast antibody tests in later stages, but at that point it is probably much too late to act.