ATLANTA—Two American missionaries who contracted Ebola in Liberia have recovered from the deadly illness and been discharged, Emory University Hospital officials said Thursday.

Smiling broadly as he appeared at a hospital news conference and looking as fit as he had in photos taken before he became ill, Kent Brantly said he was grateful to have survived a disease that kills the majority of those infected.

"I am thrilled to be alive, to be well, and to be reunited with my family," said Dr. Brantly, a 33- year-old medical missionary from Fort Worth, Tex.

Dr. Brantly and Nancy Writebol, 59 years old, spent more than two weeks in a special isolation unit at the hospital after a medical evacuation from Liberia by the two Christian charities for whom they worked. Mrs. Writebol was discharged and quietly left the hospital Tuesday, officials said Thursday.

The patients, who contracted the disease while working at the same hospital in Liberia, no longer have symptoms and don't have traces of the deadly virus in their blood, said Bruce Ribner, who heads the isolation unit where they were treated.