Ebola has killed more than 700 people so far.
Liberia is one of the West African nations hardest hit. They've shut down universities and are enforcing quarantines in some areas.
The crisis is affecting travel plans, with officials warning people to stay away from the region.
One patient is returning to the U.S. with symptoms of the disease.
Doctor Michael Calderwood is an infection control expert from Brigham and Women's Hospital, and he joined us with more on the subject.
