US health officials say an American nurse who contracted ebola while treating a dying patient is in a "clinically stable" condition.
The healthcare worker, identified as 26-year-old Nina Pham, is being treated in isolation at a hospital in Dallas.
She had been caring for Thomas Eric Duncan, who died from the virus last week.
Screening for the ebola virus has begun this morning at Heathrow airport.
Temperature checks will be introduced at terminal one for passengers arriving from Guinea, Sierra Leone and Liberia.
US Health authorities are now trying to find out whether anyone may have been infected by the nurse with ebola.
Dr Thomas Frieden is from the U.S. Centers for Disease Control and Prevention:
