The coronavirus test that wasn’t: How federal health officials misled state scientists and derailed the best chance at containment

The coronavirus epidemic this week reached Beadle County, South Dakota. A single case tied to travel has exploded into 14 infections and counting, with no way to know how many were exposed while supply shortages forced the entire state to briefly suspend testing.

Confirmed cases in New York City, where hospitals have fallen into chaos as resources run thin, on Thursday surpassed Beadle’s entire population of 18,500. With too few tests for too many cases, doctors there already had been told it no longer made sense to test most ill...