The first of a group of 10 American aid workers who may have come into contact with the virus in were evacuated on Saturday, American government and aid officials said. They will be the largest group of Americans to have returned home over fears of exposure to the virus since an outbreak in three West African countries was declared last year.
The 10 worked with the American charity Partners in Health and were determined to have varying degrees of risk but no symptoms, said Sheila Davis, who leads Ebola response efforts for the group, which she said would continue working in Sierra Leone. A medical worker for the charity was confirmed to have Ebola last week and returned to the United States on Friday.
Another worker with the group, who had shown signs of illness, arrived in the United States on Friday evening. She tested negative for Ebola twice, said several officials unaffiliated with the charity, speaking on the condition of anonymity. She was sent to Emory University Hospital in Atlanta, which has a specialized unit for Ebola patients. The hospital had no information to provide on the patient, an Emory spokeswoman said.
Officials said the evacuation might expand if necessary. The illness has killed an estimated 10,000 people in Sierra Leone, Liberia and Guinea, the three countries most affected, but only a small number of foreign aid workers have been infected, many of whom have received sophisticated critical care in Western countries and survived.
The American confirmed to have Ebola, a clinician who was not identified, tested positive for the virus on Tuesday and arrived Friday morning to the clinical center of the in Bethesda, Md. He had collapsed while volunteering at a hospital in the Port Loko district of Sierra Leone.
The Centers for Disease Control and Prevention announced on Saturday that the Americans who came into contact with him or might have had exposures similar to those that resulted in his infection would be taken into voluntary isolation close to three hospitals capable of treating Ebola patients: the University of Nebraska Medical Center, the National Institutes of Health center in Bethesda and Emory University Hospital.
Dr. Peter George, director of the Sierra Leone hospital where some of the workers were volunteering, said by phone on Saturday that an investigation was focusing on the possibility that the clinician had been exposed to Ebola while removing protective clothing on his way out of the high-risk zone at an Ebola treatment unit supported by Partners in Health near the hospital.
A Sierra Leonean community health officer, who Dr. George said worked as a monitor at the same Ebola treatment unit, was determined to have Ebola on Friday. Dr. George said he himself had been asked not to treat patients because he had treated the officer, prescribing medicines for what was initially thought to have been from a pre-existing .
On Saturday, a spokeswoman for the National Institutes of Health said there was no change to report on the infected American’s condition, which had been described as serious.
Although Americans in the past have been offered a variety of experimental treatments for Ebola, Dr. Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases, said the effect of such therapeutics was still unclear. “The only way you know that is if you do a controlled clinical trial,” he said. “We are learning a lot, but we don’t have conclusions.”
Another Ebola patient, , was treated successfully at the N.I.H. clinical center last fall. She had cared for a Liberian Ebola patient in Dallas.
, a Doctors Without Borders volunteer who developed Ebola after returning to New York from Guinea last October, also recovered, at Bellevue Hospital Center.
Dr. Martin Salia, a permanent resident of the United States who worked in his native Sierra Leone, died of Ebola at Nebraska Medical Center in November.