I tried to locate what Crowe said but was having trouble finding it.  I did see one reference that he thought there was a 1/300 false positive rate for the tests.  If you can find the original article, I'm now curious and I'd like to read it. The bigger problem is a false negative when people test too early before the disease can be detected.  People end up thinking that they're okay and then get sick just a little bit later, so they're out spreading it before they have symptoms.  (That's actually true for a lot of diseases.  You're actually contagious long before you show symptoms.)