DHAKA: US president Barack Obama urged against ‘hysteria or fear’ Saturday in the face of a growing Ebola crisis, as the United Nations spoke of an "encouraging" response to its funding appeal.

The worst-ever outbreak of the deadly virus has so far killed more than 4,500 people, mainly in three West African nations at the epicenter of the outbreak: Guinea, Liberia and Sierra Leone.

Obama’s warning came a day after the World Bank warned the battle against the disease was being lost and as the US president named an ‘Ebola czar’ to coordinate Washington’s response.

A UN appeal for nearly US$1 billion to fight the spread of the disease has so far fallen short, but a spokesman told media more money was coming in daily, reports The Straits Times.

BDST: 2200 HRS, OCT 18, 2014