An alarming new report by The Wall Street Journal suggests that nearly one in three patients who are infected with COVID-19 receive incorrectly negative test results. "A false negative is problematic because it tells the patient they don't have the virus," Dr. Craig Deligdish explained to the paper.

The estimate about the incorrect results is based on limited data, but the implication that tests may be far from accurate is worrisome. As Deligdish observed, it means that people who've been reassured they are not contagious are likely going forth and spreading the disease to others.

Health care experts additionally told The Wall Street Journal that part of the problem with the tests is how fast they've been approved. "The thing that is different this time is most of these tests are going through a really rapid validation process," said Ohio State University epidemiologist Bill Miller. "As a result, we can't be completely confident in how they will perform." Other doctors have already picked up on the faulty results; in New York City, the center of the U.S. outbreak, "a negative is not clearing anybody who is symptomatic," one emergency room doctor said.

New guidelines to sick Americans asks that if you have coronavirus symptoms, assume you have COVID-19. "Research coming out of China indicates that the false-negative rate may be around 30 percent," writes The New York Times' Harlan M. Krumholz. "Some of my colleagues, experts in laboratory medicine, express concerns the false-negative rate in this country could be even higher."

Curiously, it doesn't seem to go the other way. The Times adds, "the tests appear to be highly specific: If your test comes back positive, it is almost certain you have the infection." Jeva Lange