Ebola: what risk does the virus pose to Africa and the wider world?

Parts of Western Africa are gripped by the Ebola virus, with more than 670 dead in the current outbreak. Gideon Rachman is joined by Clive Cookson, science editor, and Javier Blas, Africa editor, to discuss how serious a threat the virus poses to the region and to the wider world, and what the international community can do to thwart its progress