ATLANTA — An American doctor infected with Ebola while working in Liberia indicated Friday he’s getting stronger every day, and the husband of a second aid worker with the deadly virus said his wife also seems to be improving.

Dr. Kent Brantly and Nancy Writebol, who had trained as a nursing assistant, are being treated in an isolation unit at Emory University Hospital in Atlanta. The two were infected while working at a missionary clinic outside Liberia’s capital.

Brantly, writing from his isolation room, said he didn’t go to Liberia specifically to fight Ebola, but his work turned toward treating more of those patients.

“I held the hands of countless individuals as this terrible disease took their lives away from them. I witnessed the horror firsthand, and I can still remember every face and name,” Brantly said in a statement put out by Samaritan’s Purse, the aid organization he was working with in Africa.

Writebol’s husband, David, who remains in Liberia, said Friday in a phone call that while he hasn’t spoken directly to his wife’s doctors, his sons told him she’s showing improvement.