MONROVIA - Liberian President Ellen Johnson Sirleaf declared a state of emergency in the West African country late Wednesday to combat an outbreak of Ebola.

The president made the announcement on state TV, saying the emergency will last for 90 days.

"Ignorance and poverty, as well as entrenched religious and cultural practices, continue to exacerbate the spread of the disease," she said.

The epidemic, which has killed at least 282 people in Liberia alone, is spread through contact with bodily fluids of those infected.

The Ebola outbreak, by far the largest in the nearly 40-year history of the disease, has killed 932 people and affected 1,711 others this year in four Western African countries -- Guinea, Liberia, Nigeria and Sierra Leone, according to the World Health Organization.