A new human coronavirus has appeared in China

BEFORE 2003 few outside the field of respiratory medicine would have heard the term “coronavirus”. Then came SARS—severe acute respiratory syndrome—and suddenly the word became familiar. SARS caused a medical panic. It was an unknown illness with a mortality rate of about 10% and there was a brief period when, having escaped from China, where it first appeared, and surfaced in places as far distant as Canada, it seemed to have the potential to cause a global epidemic.

Thankfully, SARS was contained, and now seems to have disappeared in the wild. But the bogeyman status of coronaviruses has not diminished. Hence the mini-panic when a new one began infecting people in Wuhan, the capital of Hubei province, in China. As The Economist went to press 42 patients had been confirmed as being ill with the new virus, one of whom had died.