A private security guard patrols the apartment building in Dallas where Ebola patient Thomas Duncan stayed. The family that hosted him is quarantined. Tom Pennington/Getty Images hide caption

itoggle caption Tom Pennington/Getty Images

The two American Ebola patients are being cared for separately in rooms like this in the special isolation unit, known officially as the Serious Communicable Disease Unit, at Emory University Hospital. Emory University Hospital hide caption

itoggle caption Emory University Hospital