The NIH patient was flown in isolation from Sierra Leone on a chartered plane and admitted at 4:44 a.m., NIH officials said in a statement.
    The patient's name, age and gender were not released.
    The patient is the 11th person with Ebola to be treated in the U.S. and the second admitted to the NIH Clinical Center. Like Emory, NIH has one of the few specialized isolation units nationwide set up to treat Ebola patients. The center's Special Clinical Studies Unit is staffed by specialists in infectious disease and critical care and is designed to prevent the spread of highly contagious viruses, including Ebola. Previously, an American nurse was treated there after she contracted Ebola while caring for a patient in a Dallas hospital. The nurse, Nina Pham, survived and is Ebola-free.
    None of the volunteers in Sierra Leone who had contact with the NIH patient have tested positive for Ebola. The CDC and the U.S. State Department have developed contingency plans for flying home other Americans in that group, who would also be expected to isolate themselves for 21 days.
    The World Health Organization estimated Thursday that the virus has killed more than 10,000 people, mostly in the West African nations of Guinea, Liberia and Sierra Leone. The current outbreak is the largest ever for the disease. While deaths have slowed dramatically in recent months, the virus appears stubbornly entrenched in parts of Guinea and Sierra Leone.