In an attempt to manage anxiety over bird flu, Sir Liam Donaldson, the UK’s chief medical officer, told the media a pandemic was unlikely this winter and emphasised the government’s preparedness as exemplified in its stockpiling of antiviral drugs. The fact he has been wheeled out confirms that a large part of fighting an epidemic involves managing the psych­o­logy of the public.

Panic, fear and flight have characterised society’s response to epidemics throughout history: collective memory of the suffering and threat to the fundamental survival of civilisation accounts for their deep psychological impact. When, for example, European germs were brought to the New World, the American Indian population plummeted to 5 per cent of what it had been pre-Columbus. Half of Europe’s population died during the 14th-century Black Death. The death toll of the influenza epidemic after the first world war equalled that of the military operations; and, according to recent data from the Centre for Disease Control in the US, even today in Iraq and Sudan germs are still deadlier than guns.