FILE- This 2013 file photo provided by United Brethren in Christ, shows Dr. Martin Salia. Salia who was diagnosed with Ebola on Monday, landed at Eppley Airfield in Omaha, Neb. and was being transported to the Nebraska Medical Center. (AP Photo/United Brethren in Christ, Jeff Bleijerveld, File)
A surgeon who contracted the Ebola virus while working in Sierra Leone is fighting for his life at a Nebraska hospital, where doctors say his condition is "extremely critical."