Another missionary with Ebola being brought back to the U.S.

(NEWSCHANNEL 3) - Another American medical missionary stricken with the deadly Ebola virus in West Africa is expected to fly back to the U.S. on Tuesday.

Nancy Writebol will join colleague Dr. Kent Brantly in the Infectious Disease Unit at Atlanta's Emory University Hospital.

Brantly's arrived back in the U.S. this weekend. His wife says his condition is improving and he thanked everyone for their prayers.

Right now more than 50 African heads of state are in Washington. They're here for a three-day summit.

"We are working very closely, as I said, with the CDC. We're making sure that we're going to observe any necessary protocols for screening."

There is no cure for the Ebola virus. At least 729 people have died in West Africa this year.