Two American aid workers infected with the Ebola virus in Africa will be treated at a specialized unit of an Atlanta hospital.

Dr. Bruce Ribner said Friday the patients will receive care at Emory University Hospital. Ribner oversees the isolation unit. He said he had no personal safety concerns over treating the patients of the disease.

Hospital officials did not identify the patients, citing confidentiality rules. They were previously identified as Dr. Kent Brantly and Nancy Writebol.

Emory spokesman Vincent Dollard said the first patient was expected to arrive Saturday afternoon. It was not immediately clear when the second patient would arrive.

The Pentagon’s press secretary, Navy Rear Adm. John Kirby, said Friday that private-chartered aircraft will arrive with the patients at Dobbins Air Reserve Base near Atlanta  There’s never been a case of Ebola in the U.S. and many are expressing concerns about the spread of the virus.

Ebola is considered one of the world’s deadliest diseases. The current outbreak in Liberia, Guinea and Sierra Leone has sickened more than 1,300 people and killed more than 700 this year.

The virus is spread through direct contact with blood, urine, saliva and other bodily fluids from an infected person. It is not spread through the air so it is not as infectious as a germ like the flu.