Coronavirus: asymptomatic Wuhan woman shows why outbreak 'will be hard to stop'

Case study of 20-year-old who infected relatives despite not showing signs of illness - and testing negative - stokes global pandemic fears

A 20-year-old Chinese woman from Wuhan travelled hundreds of miles to another city where she is believed to have infected five relatives without showing signs of infection, scientists in China have said, offering fresh evidence that the new coronavirus can be spread asymptomatically.

The case study, published in the Journal of the American Medical Association, offered clues about how the coronavirus is spreading, and suggested it might be difficult to stop.