Jennifer Nuzzo

The World Health Organization, Africa's CDC, and governments in affected countries have made big improvements to testing and contact tracing.

But Jennifer Nuzzo, director of the Pandemic Center at Brown University, says U.S.

leadership is missing.

The U.S.

sent more than $160 million in financial aid to the region...

but it's taking a hands-off approach compared with past outbreaks.

Initial efforts focused on U.S.

border restrictions.

The CDC says it's helping with strategic and technical assistance.

Nuzzo says the costs and concerns of this outbreak will not end until it's contained at the source.

Ping Huang, NPR News.