OMAHA, Neb. — A surgeon who contracted Ebola in Sierra Leone has arrived in the United States for treatment.

Dr. Martin Salia landed at Eppley Airfield in Omaha on Saturday afternoon and will be transported to the city’s Nebraska Medical Center.

The hospital says the medical crew transporting Salia described his condition as critical, and that he is possibly in worse condition than other people treated for the disease in the United States.

Salia will be the third Ebola patient to be treated at the Omaha facility.

Salia came down with Ebola symptoms Nov. 6, but tested negative for the virus. He tested positive on Monday.

He was working as a general surgeon at Kissy United Methodist Hospital in the Sierra Leone capital, Freetown, which is not an Ebola treatment unit.

The disease has killed more than 5,000 people in West Africa, mostly in Liberia, Guinea and Sierra Leona. Of the 10 people treated for Ebola in the U.S., all but one has recovered.

Salia is a Sierra Leone citizen who lives in Maryland.