Doctors at UMass Memorial Medical Center released the results of tests run on Dr. Rick Sacra, showing that he does not have the Ebola virus again.
Sacra, 51, was put under observation on Saturday after he came to a Boston-area emergency room with complaints of a persistent cough and other fatigue.
"We are removing Dr. Sacra from isolation, and his physicians are continuing routine care for his upper respiratory tract infection," said a statement released Sunday night by UMass Memorial Medical Center.
He had been volunteering in Liberia with SIM USA, a missionary organization, when he contracted the virus. He was sent back to the United States for treatment.
Sacra was the third American to be diagnosed with the Ebola virus recently. The first two, Nancy Writebol and Dr. Kent Brantly, who volunteered with the same missionary organization, were taken from West Africa and treated in an isolation unit in Atlanta. They were released in August
The fourth, Thomas Eric Duncan, was diagnosed Sept. 30 at a medical center in Dallas and is listed in critical condition. Another American, Ashoka Mukpo, a freelance camerman for NBC News was diagnosed last week and is en route to the United States and is expected at Nebraska Medical Center on Monday.