The world needed to work fast so it did not become "the next Aids", the director of the Centers for Disease Control and Prevention (CDC) said.
Dr Frieden was addressing a high-level World Bank forum about the crisis.
The outbreak has killed more than 3,860 people, mainly in West Africa, including more than 200 health workers.
On Thursday, a Liberian doctor died of the disease at a treatment centre in Monrovia, health officials said.
Thomas Frieden made his remarks at a World Bank meeting in Washington
Ugandan-born John Taban Dada had been working at the country's largest hospital, the John F Kennedy Memorial Center, his former colleagues said.
source - bbc news

