A US resident who got infected with Ebola in Sierra Leone is critically ill, the hospital treating him has said.

Dr. Martin Salia was flown to the University of Nebraska Medical Center on Saturday, November 15 for treatment and is said to be in "extremely critical" condition.

Salia is a native of Sierra Leone but married a US citizen. He was treating patients with the disease in his home country when he took ill.

The hospital said via Twitter:

“3rd Ebola patient still extremely critical. Maximum supportive care and every available treatment option being used to save his life.”

Nine people have been treated for Ebola in the US and only one, Liberian Thomas Eric Duncan, died.

Salia is the third Ebola patient to be treated at the Nebraska hospital and the two previous patients, Dr. Rick Sacra, and NBC cameraman, Ashoka Mukpo survived.