Ebola crisis: Obama says US outbreak risk very low

US President Barack Obama has played down the chance of an Ebola outbreak in the US, after a second nurse became infected caring for a patient.

He said the risk of Americans getting the virus was "extremely low" but more needed to be done to help West Africa.

Amber Vinson, 29, fell ill on Tuesday, after treating Liberian Thomas Eric Duncan, who died a week ago in Dallas. Health authorities in the United States are contacting the 132 passengers who shared a Dallas-bound flight with a woman who later tested positive for Ebola.

Alastair Leithead reports.