The third American to become infected with the Ebola virus while working on a mission in Liberia arrived at Nebraska Medical Center for treatment Friday morning.

Dr. Rick Sacra will begin treatment in the hospital’s Biocontainment Patient Care Unit, according to a release from the international Christian mission organization. Two other Americans recovered from the virus after being taken to the United States for treatment last month.

“Rick was receiving excellent care from our SIM/ELWA staff in Liberia at our Ebola 2 Care Center,” said Bruce Johnson, president SIM USA.  “They all love and admire him deeply.  However, The Nebraska Medical Center provides advanced monitoring equipment and wider availability of treatment options.”

Dr. Rick Sacra, a 51-year-old Boston physician, is the latest worker for SIM USA to be infected with the virus that has killed more than 1,900 people.

Sacra had volunteered to return to Liberia, where he has long offered medical services, when two other U.S. health workers were infected with the virus.

A Reuters cameraman saw Sacra, wearing a white protective overall, step out of the car that brought him to the tarmac. He walked into the aircraft.

“SIM’s global family from over 50 countries is extremely grateful for the generous cooperation of many agencies and organizations in the U.S. and in Liberia which made it possible for Rick to be brought to Omaha.  It took an exceptional effort across many organizations to make this happen.  We particularly thank the U.S. Department of State and its many agencies and The Nebraska Medical Center.”

Sacra, a 51-year-old physician from Massachusetts, was working in the obstetrics unit of the massive Elwa Hospital in the Liberian capital of Monrovia, far from the Ebola unit, said Dr. Jeff Deal, a South Carolina doctor who traveled to Liberia to help battle the crisis engulfing much of Africa.

Doctors and other health care workers often do not wear protective gear in the general part of the hospital, most of which has no air conditioning. With high temperatures compounded by equatorial humidity, many doctors and health care workers outside of the Ebola unit skip protective gear.

Reuters and the Associated Press contributed to this article.