Barack Obama has conceded it "may be appropriate" to choose an Ebola "tsar" to lead the US response against the disease.

A Liberian Ebola patient was left in an open area of a Dallas hospital for hours, the largest US nurses’ union has said.

The first Ebola patient diagnosed in the United States died today, a little more than a week after his illness exposed gaps in the nation’s defences against the disease and set off a scramble to track down anyone exposed to him.

The first person to develop ebola in the US was struggling to survive at a Dallas hospital yesterday after his condition worsened to critical, the director of the US Centres for Disease Control said.

The condition of the man who brought the deadly Ebola disease to the US is now critical, hospital officials have said.