The Ebola outbreak in West Africa was first reported in March 2014, and has rapidly become the deadliest occurrence of the disease since its discovery in 1976.

In fact, the current epidemic sweeping across the region has now killed more than all other known Ebola outbreaks combined.

Up to 23 October, 4,951 people had been reported as having died from the disease in five countries; Liberia, Guinea, Sierra Leone, Nigeria and the United States. A further death has been reported in Mali.

The total number of reported cases is in excess of 13,500.

The World Health Organization (WHO) admits the figures are underestimates and warns there could be as many as 20,000 cases by November if efforts to tackle the outbreak are not stepped up
Note: figures are occasionally revised down as suspect or probable cases are found to be unrelated to Ebola The WHO has published updates on the spread of the virus in each of the countries affected.

The figures given are for "confirmed, probable and suspected" cases and deaths. They have occasionally been revised down to take account of changes in the countries' reporting methods, for example by excluding the "suspected" cases.

2014 outbreak in context

Ebola was first identified in 1976 and occurs in regions of sub-Saharan Africa. There are normally fewer than 500 cases reported each year, and no cases were reported at all between 1979 and 1994.

In August 2014 the WHO confirmed a separate outbreak of Ebola in the Democratic Republic of Congo. By the beginning of October there had been 70 cases reported and 43 deaths.

However, the...