The president of a missionary group says a third American sickened with the Ebola virus decided to return to Liberia after the other two people became ill.

SIM President Bruce Johnson said at a news conference Wednesday that Dr. Rick Sacra returned to Liberia about a month ago after another doctor and a missionary became ill with Ebola.

Both survived after treatment at Emory University Hospital in Atlanta.

Johnson says the 51-year-old Sacra lives in the Boston area. He says Sacra wasn't caring for Ebola patients but was delivering babies in the SIM hospital's obstetrics unit.

He says it's not known whether Sacra will return to the U.S. for treatment.

The missionary who survived Ebola, Nancy Writebol, said at the news conference that she believes an experimental drug, her medical care and her faith helped save her.

Writebol says it's wonderful to be back in the United States, but she's still thinking about Liberia.

Speaking publicly for the first time at a press conference today in North Carolina, the Christian missionary who survived an Ebola infection says more needs to be done in the west African country. 

She thanked doctors in the United States and Liberia for taking care of her health and the health of others.  

Speaking alongside her husband David, Writebol said her brush with the potentially-deadly virus won't deter her faith or prevent her from going on more mission trips to serve suffering people.  

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