Customs and health officials at airports in Washington, Chicago, Atlanta and Newark will take the temperatures of passengers from three West African countries starting Thursday.

Federal health officials say the entry screenings add another layer of protection to halt the spread of the Ebola virus that has killed thousands. Screeners will use no-touch thermometers to try to find passengers with fevers.

The screenings started at New York’s Kennedy International Airport Saturday. The Centers for Disease Control and Prevention said Tuesday that screenings will start Thursday at Washington Dulles, Chicago O’Hare, Newark’s Liberty and Hartsfield-Jackson in Atlanta.

Customs officials say about 150 people travel daily from or through Liberia, Sierra Leone or Guinea to the United States. Nearly 95 percent of them land first at one of those five airports.

(AP)