text: TUBMANBURG, LIBERIA - OCTOBER 15: A U.S. Marine checks the temperature of Maj. Gen. Darryl Williams, commander of U.S. Army Africa, before boarding an MV-22 Osprey tiltrotor aircraft on October 15, 2014 in Tubmanburg, Liberia. The general visited the site of the first of 17 Ebola treatment centers being constructed by Liberian forces under American supervision as part of Operation United Assistance to combat the Ebola epidemic. (Photo by John Moore/Getty Images