About a week after being admitted to the National Institutes of Health Clinical Center in Bethesda, a health care worker exposed to Ebola in Sierra Leone has not tested positive for the virus, officials said Wednesday.
NIH doctors "are continuing to observe and monitor the person," the agency said in a statement. It can take as long as three weeks after Ebola exposure for a person to develop symptoms and become contagious.
Officials have not released further details on the patient, other than to say the case involved "high-risk exposure."
The person is at least the third suspected or confirmed to have Ebola to be treated at the government research hospital.
Staff at the facility successfully treated nurse Nina Pham earlier this year after she contracted the virus while treating an infected Liberian man in Dallas. The hospital also admitted and released an American doctor exposed to Ebola in Sierra Leone who never tested positive for the virus.