Dr. Rick Sacra, the third American doctor to become infected with Ebola in West Africa, has arrived in the United States. He landed in Nebraska and has gone to a hospital for treatment after contracting the disease in Liberia.

The American doctor from the Boston area landed at Offutt Air Force Base Friday morning and was transported to the University of Nebraska Medical Center in Omaha on a gurney, according to ABC News.

Sacra, 51, had been working in the Liberian capital of Monrovia at the ELWA Hospital, where he was quickly placed in the isolation ward. However, it is uncertain how he contracted the disease because he was caring for pregnant women in the hospital.

Sacra is an assistant professor of medicine at the University of Massachusetts Medical School and had previously been in Liberia. He had traveled to Liberia with the international, interdenominational Christian organization known as SIM.

"I just had a call from the doctor who put Rick on a plane to come to the United States," said Debbie Sacra, his wife, at a news conference. "He said that Rick is clearly sick but that he was in very good spirits."

She also said the are hopeful for his recovery: "He walked onto the plane, so we are really encouraged by that news and looking forward to reuniting with him."

According to Al-Jazeera, the hospital where Sacra was taken has a specialized 10-bed isolation ward, "the largest of four such units in the United States."

"This unit was specifically designed to care for patients of this nature and is staffed with infectious disease experts who have prepared for years for situations like this one," explained Dr. Phil Smith, medical director of Nebraska's biocontainment unit, according to NBC News.

"The unit is sealed, guarded and secure. It's separate from other patient care areas, and just like the facility at Emory University, which successfully treated two Americans with Ebola last month, we are uniquely prepared to handle infectious diseases here."