In 60 seconds: What is Ebola? World's Deadliest Disease?

Link: http://www.bbc.com/news/health-28105531

In 60 seconds: What is Ebola?

The World Health Organization (WHO) has called for "drastic action" to contain the Ebola outbreak in West Africa, which has killed nearly 500 people.

It is the world's largest outbreak in terms of cases, deaths and geographical spread.

The BBC explains why the disease is so dangerous - in 60 seconds.

Video produced by Michael Hirst