Story highlights The health care worker was in Sierra Leone, one of the hotbeds of Ebola

The patient is not currently ill nor contagious, but had "high-risk exposure" to Ebola

(CNN) An American health care provider working in Sierra Leone who had a "high-risk exposure" to the Ebola virus arrived at Nebraska Medicine on Sunday for "observation and possible treatment," the center said.

"This patient has been exposed to the virus but is not ill and is not contagious," said Dr. Phil Smith, medical director of the biocontainment unit at the Omaha medical center.

"However, we will be taking all appropriate precautions."

Nebraska Medical Center, part of Nebraska Medicine, is one of only four hospitals in the United States that has biocontainment units and has been practicing for years to treat a highly infectious disease such as Ebola.

The other three hospitals are Emory University Hospital in Atlanta; Rocky Mountain Laboratories in Montana; and the National Institutes of Health in Maryland.

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