The screening will start at New York’s John F. Kennedy airport from the weekend, and later be used at Newark Liberty, Washington Dulles, Chicago O’Hare and Hartsfield-Jackson Atlanta. Duncan was able to fly to the United States from Liberia because he did not have a fever when screened at the airport in the capital, Monrovia, and filled out a questionnaire saying he had not been in contact with anyone infected with Ebola.