Seen through a window, U.S. Centers for Disease Control and Prevention officials have a conference call on Ebola with CDC team members deployed in West Africa from the agency’s Emergency Operations Center, Tuesday, Aug. 5, 2014, in Atlanta. An American aid worker infected with Ebola arrived Tuesday from Liberia to Emory University Hospital, just downhill from the CDC, joining a second patient being given an experimental treatment that has never before been tested on humans.