The world should be more anxious than it was a week ago. According to research published on Friday, a new Sars-like coronavirus has been present in China since December 1, a full month before the alarm was raised. Almost 3,000 people have been diagnosed with the respiratory illness. As of Monday afternoon, 35 cases were outside China. Eighty-one people have died.

Despite draconian quarantining, the virus, provisionally known as 2019-nCoV, is spreading. Several countries, including the UK, are considering evacuating nationals from the hot zone. It is now time for the World Health Organisation to call a Public Health Emergency of International Concern (PHEIC).

The revised timeline on when the virus began circulating comes courtesy of two papers in The Lancet medical journal, which reveal other worrying details. One sets out the clinical data on the first 41 laboratory-confirmed patients.