An American health care worker with Ebola who is being treated at the National Institutes of Health has improved from critical to serious condition.
The worker contracted Ebola while volunteering in a Sierra Leone treatment unit and arrived at the hospital earlier in March.
The person is a clinician working with Partners in Health, a Boston-based nonprofit organization.
The group has been treating patients in Liberia and Sierra Leone since November.
The Associated Press contributed to this report.