The accuracy of tests for SARS-CoV-2 is central to our ability to control the epidemic— knowing who is infected, who has been exposed, and who is immune. It is also central to our ability to reopen businesses and lift restrictive lockdown measures. Unfortunately, our tests are not up to the job, nor are they available and affordable to all those in need. But that does not mean we don’t have ways to blunt the damage that our testing failures may cause.
As Bloomberg reported over the weekend, doctors trying to diagnose patients are saying that false negative results from coronavirus tests are becoming an increasing concern, impeding their ability to correctly diagnose patients and preventing us from truly understanding the spread of the disease. The tests for the presence of the virus itself can miss thirty to forty percent of those actually infected, sometimes even more. These false negatives are due in many cases to individual variation in the actual level of the virus, the technique used by the tester, and issues with the tests themselves.
Originally published on Forbes (April 13, 2020)