Some Patients With Wuhan Coronavirus Only Show Mild Symptoms. Here’s Why That’s a Problem

As researchers fight to stop the spread of a novel coronavirus that originated in a seafood market in the central Chinese city of Wuhan, they are facing a counter-intuitive problem: the symptoms can sometimes be so mild in patients that the virus is very difficult to detect.

The Wuhan coronavirus, dubbed 2019-nCoV, has killed at least 106 people in mainland China, out of the 4,400-plus documented cases.