But nasty bugs derived from Chinese livestock markets never fail to whip up mass hysteria. As with H5N1, as with coronavirus. Perhaps wisely, given its past history of crying wolf over bird flu, the WHO has so far stopped short of declaring the latter a global emergency. But China is certainly in panic. The city of Wuhan, along with several others, has been cut off to public transport. Tourist sites have been closed, including, appropriately enough, the Forbidden City in Beijing. Newsreaders have appeared on screen wearing facemasks — just in case, presumably, one of their viewers coughs over the TV set. In Wuhan, health authorities have apparently set themselves the task of building an entire new hospital in under a week. And the panic seems to have spread to Europe, too, with airline passengers being scanned for signs of high temperature (which of course could have a hundred causes other than coronavirus).

Yet while all this has been going on, the virus has been proving itself pretty poor at killing its host. Up until Thursday pm 571 cases had been confirmed and a further ten in other countries. Of these, 95 were reported to be seriously ill and 17 people have died — most of them, it is reported, had pre-existing medical conditions. That is pretty mild compared with the worst flu seasons in Britain. By this stage of the winter two years ago flu was already reported to have killed 155 people.