ATLANTA -- At least one of the two American aid workers who were infected with the deadly Ebola virus in Africa has recovered and is set to be discharged Thursday from an Atlanta hospital, the aid group he was working for said.

Alison Geist, a spokeswoman for Samaritan's Purse, confirmed Dr. Kent Brantly would be released Thursday but could not say what time. Emory University Hospital planned to hold a news conference Thursday morning to discuss both patients' discharge.

Franklin Graham, president of North Carolina-based Samaritan's Purse, said in a statement that the group was celebrating Brantly's recovery. He has been in the hospital's isolation unit for nearly three weeks.

"Today I join all of our Samaritan's Purse team around the world in giving thanks to God as we celebrate Dr. Kent Brantly's recovery from Ebola and release from the hospital," Graham's statement said.

Brantly was flown out of the west African nation of Liberia on Aug. 2, and Nancy Writebol followed Aug. 5. The two were infected while working at a missionary clinic outside Liberia's capital.

The Ebola outbreak has killed 1,350 people and counting across West Africa.

On Thursday in the Liberian capital of Monrovia, calm set in one day after residents in a slum that was sealed off in an effort to contain the outbreak clashed with riot police and soldiers. World Health Organization officials were visiting two hospitals that are treating Ebola patients and struggling to keep up with the influx of patients.

The death toll is rising most quickly in Liberia, which now accounts for at least 576 of the fatalities, the WHO said. At least 2,473 people have been sickened across West Africa - more than the caseloads of all the previous two-dozen Ebola outbreaks combined.

Ebola is only spread through direct contact with the bodily fluids of sick people experiencing symptoms.

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