Emory University Hospital in Atlanta will treat its third U.S. Ebola patient, according to the Associated Press. The unidentified aid worker was one of many World Health Organization doctors working in an Ebola treatment center in Sierra Leone. The patient will be flown into Dobbins Air Reserve Base outside Atlanta and is expected to arrive at the center on Tuesday.

A fourth U.S. Ebola patient, Richard Sacra, tested positive for the infectious disease that has killed more than 2,100 people across five countries in West Africa and is being treated in Nebraska. Sacra, a missionary doctor working in Liberia with international mission organization SIM, arrived at the Nebraska Medical Center in Omaha Friday and is said to be responding well to treatment, according to the Washington Post.

Two Americans infected with the Ebola virus while working in West Africa were previously treated at Emory. Kent Brantly and Nancy Writebol, both health care workers, arrived by air ambulance from Liberia. Brantly was admitted to Emory on Aug. 2 and Writebol arrived on Aug. 5. Both patients were discharged from the hospital a few weeks later after receiving an experimental treatment for the disease.

"After a rigorous course of treatment and thorough testing, we have determined, in conjunction with the Centers for Disease Control and state health departments, that Dr. Brantly has recovered from the Ebola virus infection, and that he can return to his family, to his community, and to his life without public health concerns," Bruce Ribner, medical director of Emory's infectious disease unit, said in a press conference.

It is unclear if the third Emory patient will receive the same treatment. The aid worker will be held in the hospital’s isolation unit, according to the AP.