Security personnel guard a patient's entrance at the National Institutes of Health in Bethesda, Maryland on Oct. 16, 2014.
Photo by Gary Cameron/Reuters

US Ebola patient in critical condition

An American being treated for Ebola at the National Institutes of Health outside Washington, D.C. is now in critical condition, the NIH said Monday.

It’s bad news for the health care worker who was infected in Sierra Leone while trying to help fight the West African epidemic, which has sickened more than 24,000 people and killed more than 10,000 of them in a year.

“NIH physicians have changed the status of the patient with Ebola virus disease being treated at the NIH Clinical Center from serious to critical condition. No additional details about the patient are being shared at this time,” NIH said in a statement.

The patient works for Partners in Health, a group that has 2,000 employees in West Africa, including 100 expatriates.

The group says 10 other clinicians who worked to help the Ebola-infected patient are being evacuated to the United States for observation because they may have been exposed to the virus. One has been taken to the biocontainment unit at the University of Nebraska’s medical center after developing symptoms.

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“At this point, this person has not tested positive for the Ebola virus,” said Dr. Phil Smith, medical director of the unit. “However, because of a change in symptoms, we decided the most prudent course of action was to bring the individual to the Biocontainment Unit, where we can better monitor symptoms and safely perform testing. However, some of the symptoms which prompted the move to the Biocontainment Unit have resolved this morning.”

They others will all self-quarantine outside of three special isolation units where Ebola patients have been treated: at the NIH, Emory University Hospital in Atlanta and the Nebraska Medical Center. They can be speedily treated if they begin to show symptoms.

This article originally appeared on NBCNews.com

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US Ebola patient in critical condition