U.S. authorities will monitor people coming from Liberia, Sierra Leone and Guinea for Ebola for 21 days, part of an aggressive new program to prevent the deadly virus from entering the country.

The U.S. Centers for Disease Control and Prevention will ask travelers from the countries to give their name and contact information, and states will follow up with them, said CDC Director Tom Frieden on a conference call today.

Monitoring by six states — New York, New Jersey, Pennsylvania, Georgia, Virginia and Maryland — will begin Oct. 27. Travelers will have to report their temperature and the emergence of any symptoms, and report to authorities if they plan to travel inside the U.S.

To contact the reporter on this story: Drew Armstrong in New York at darmstrong17@bloomberg.net. To contact the editors responsible for this story: Reg Gale at rgale5@bloomberg.net. 

Photo Credit: Thomas Frieden, MD, CDC, gives an update on ebola at the Kaiser Permanente Center for Total Health. Ted Eytan / Flickr