The current Ebola virus outbreak in Guinea, Sierra Leone and Liberia is the biggest ever in terms of fatalities, geographical distribution and duration. A person sick with it flew from Liberia to Nigeria, the most populous country in Africa, from which many travellers arrive in the UK every day. So it was no surprise to hear that COBRA has met. Announcing that it has met is in itself crisis management: ‘We are aware of the problem and something is being done.’

How big is the risk? Two pieces of ‘good’ news. First, the great majority of cases are in countries whose inhabitants are very unlikely to travel to the UK by air. Even if they wanted to, they don’t have the money to buy a ticket. Second, Ebola is hard to catch. It is not spread on the wind. Those incubating the disease don’t spread it. Close contact with body fluids from someone with symptoms is needed. That is why most victims are carers in a domestic setting, people carrying out traditional funeral practices including the washing of the corpse, and nurses and doctors.

The bad news for preventing international spread is that the incubation period can be more than a week and that the early stages of the disease mimic much commoner diseases like malaria and gastroenteritis. Only later does a skin rash and bleeding from orifices and into the skin rule them out. By far the most important action to be taken in the UK right now is to ask ill people very recently arrived from Africa which country they have come from.

In November 1976 a scientist at Porton Down pricked his thumb through a rubber glove while transferring homogenised liver from a guinea pig infected with virus isolated during the first recorded outbreaks of the disease. He immediately plunged the thumb into bleach. Too late. He survived after a stormy illness. This has been the only case of Ebola in the UK to date. The risk of another remains very low.