An American doctor who is now being treated in the United States for the Ebola virus is improving from treatment, according to Reuters.
Dr. Kent Brantly arrived in the United States on Saturday and is being treated in Atlanta.
A second American who has contracted Ebola is expected to arrive in the United States on Tuesday.
More than 700 people in West Africa have died from Ebola since February, and President Obama has said some people traveling to Washington for the African leaders summit beginning Monday will be screened for the virus.
Worries increased Sunday, after reports that a passenger on a flight that originated in Sierra Leone died after getting off a plane in Gatwick Airport in England.
Fears have swirled around the three-day conference in Washington that will bring nearly 50 African officials to the capital for an unprecedented gathering that officials said could be a turning point in U.S.-Africa relations.
But now, Obama administration officials are competing with increasingly dire news out of West Africa, where Ebola is ravaging populations in Guinea, Liberia and Sierra Leone.
At least two African leaders will forgo the conference as a result with the death toll topping 700.
On Sunday, Frieden told CBS’s “Face the Nation” that it was impossible to “hermetically seal the borders of the U.S.”
“We're reliant and interdependent with the world for travel, for trade, for economy, for our families and communities,” he added.