How worried should we be about the spread of Ebola?

An outbreak of Ebola, which has no cure and has a 90 per cent death rate, has now killed more than 670 people across West Africa.

Following the death of Patrick Sawyer - who was allowed to travel on several international flights despite showing signs of the virus - in Lagos, health officials in Britain have warned that the spread of the disease is a cause for concern.

“[It is] the largest outbreak of this disease to date,” explained Dr Brian McCloskey, director of global health at Public Health England.

It's clear the outbreak is not under control.

• Dr McCloskey

Professor David Heymann, head of the Centre on Global Health Security at Chatham House explained: “There has been a lack of international cooperation as to the recommendations of what needs to be done [to stop the disease spreading] – and much greater collaboration is needed.

“But at the same time it's false to say that border controls can stop infections from spreading."

Speaking to the BBC’s Today programme, expert virologist Professor John Oxford said it was likely airports like Heathrow in London would be making extra efforts to keep an eye on people coming in from West Africa.

“I think you have to be careful to balance between panic – because we know from the past that you can’t stop aircraft flying – and alertness," he explained.