Microsoft Corp. co-founder Paul Allen's charitable foundation on Thursday will announce it is donating $9 million to support U.S. efforts to fight the Ebola outbreak in West Africa, a source said.

The gift to the Centers for Disease Control and Prevention (CDC) comes at a time when international groups, including Doctors Without Borders and the World Health Organization, have said resources to contain the epidemic and treat those affected are falling tragically short.

Allen said the donation from the Paul G. Allen Family Foundation will help CDC establish emergency operations centers in Guinea, Liberia and Sierra Leone, where the worst Ebola outbreak on record has killed about 2,300 people and shows no sign of slowing six months after it began.