(Adds details from news conference and statements)
By Rich McKay
ATLANTA, Aug 21 (Reuters) - Two American aid workers who just weeks ago were gravely ill with Ebola they contracted in Liberia now pose no health risk to the public after being cleared of the virus and released from an Atlanta hospital, one of their doctors said on Thursday.
Dr. Kent Brantly and Nancy Writebol, who both contracted the deadly virus while working for Christian organizations, were discharged after blood tests showed no evidence of the virus and eased symptoms, said Dr. Bruce Ribner, medical director of the infectious disease unit at Emory University Hospital.
They are likely to make a complete recovery from the disease that has killed 1,350 people in West Africa, Ribner said.
"I am forever thankful to God for sparing my life," Brantly, who was working for the Christian relief group Samaritan's Purse, said during a news conference that marked his first public appearance since walking into the hospital wearing a bio-hazard suit on Aug. 2.
In a separate statement, Christian mission group SIM USA said Writebol was released from the hospital on Tuesday and was resting in an undisclosed location with her husband.
"Nancy is free of the virus, but the lingering effects of the battle have left her in a significantly weakened condition," her husband, David Writebol, said in a statement. "We decided it would be best to leave the hospital privately to be able to give her the rest and recuperation she needs at this time."
Ribner, who cared for the patients, said they were released in consultation with the U.S. Centers for Disease Control and Prevention.
"To the extent that we've tested, there is no evidence of Ebola virus in their bodies," Ribner said.
Asked whether the experimental drugs used on the patients helped improve their survival, he said, "The honest answer is we have no idea." said what did know going into the treatment, however, was that the "key to surviving Ebola is aggressive supportive care," which is something Emory medical workers knew they could deliver to the patients more effectively Africa.
The World Health Organization said on Wednesday that 2,473 people have been infected and 1,350 have died since the Ebola outbreak was identified in remote southeastern Guinea in March.
It said that no cases of the disease had been confirmed outside of Guinea, Sierra Leone, Liberia and Nigeria, despite cases having been suspected elsewhere. (Additional reporting by Joe Bavier in Abidjan, Daniel Flynn in Dakar and Julie Steenhuysen in Chicago; Writing by Colleen Jenkins; Editing by Louise Ireland, Bill Trott and Susan Heavey)