Magnified Ebola virus
Media playback is unsupported on your device

West Africa on Ebola virus high alert

25 March 2014 Last updated at 20:03 GMT

Sierra Leone has become the latest country to be put on alert over a potential outbreak of the deadly Ebola virus.

Cases of the disease, which kills up to 90% of those infected, have also been registered in neighbouring Guinea and Liberia.

Tulip Mazumdar reports.