Dr. Thomas Frieden, director of the U.S. Centers for Disease Control and Prevention, talks with Doctors Without Borders staff during a visit in August to an Ebola treatment center in Monrovia, Liberia. Tommy Trenchard for NPR hide caption

itoggle caption Tommy Trenchard for NPR

Shops are closed in Monrovia's West Point neighborhood as part of a quarantine to contain the spread of Ebola. Zoom Dosso/AFP/Getty Images hide caption

itoggle caption Zoom Dosso/AFP/Getty Images