The number of people infected with the deadly Ebola virus reached 20,381 people by the end of 2014, and 7,989 of them died of the disease, according to figures released Friday by the World Health Organisation (WHO).The data includes confirmed, suspected and probable cases recorded in Guinea Conakry and Sierra Leone until Dec 31 and in Liberia until Dec 28.The country most severely affected by the epidemic is Sierra Leone, where 9,633 infections and 2,827 deaths have been reported, followed by Liberia with 8,018 infections and 3,423 deaths.Meanwhile, in Guinea Conakry, there were 2,730 infections and 1,739 deaths recorded in 2014.This is the worst Ebola epidemic since the virus was discovered in 1976, approximately 100 km from the Ebola river in the Democratic Republic of Congo.