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.

Few specific details have been released about their conditions. Emory has declined comment, citing patient privacy.

Brantly and Writebol were given doses of an experimental treatment before leaving Liberia. Writebol’s husband, David, said she has received another dose since arriving in Atlanta. It wasn’t immediately clear whether Brantly had also received another round of the medication in Atlanta. The treatment, which aims to boost the immune system’s efforts to fight off Ebola, is still in development and hasn’t been tested in humans.