The development agency Oxfam says rich countries must act swiftly to repair battered health systems and get cash to millions of families in the three countries hit hardest by the world's worst Ebola outbreak.

In a statement Tuesday, the group called for a post-Ebola "Marshall Plan" that would help Liberia, Sierra Leone and Guinea restore previously strong economic growth rates.

Oxfam GB Chief Executive Mark Goldring said families in the three countries have "gone through hell" in no small part because the international community reacted slowly to the outbreak at first. He said a similarly sluggish effort during the recovery period would lead to a "double-disaster."

The World Health Organization says Ebola has killed more than 8,600 people in Liberia, Sierra Leone and Guinea, though new cases are declining.