An American doctor who contracted the Ebola virus in West Africa was flown home under elaborate precautions on Saturday and taken to an isolation unit at Emory University Hospital in Atlanta.

Kent Brantly, 33, became the first person with Ebola — an astoundingly deadly virus first discovered in Africa — ever brought to the United States. Another American, missionary Nancy Writebol, was also stricken with the disease in Liberia and is expected to be brought to Emory in the coming days.

Brantly left Monrovia, Liberia, on a private plane converted into an “air ambulance” and landed at an airbase outside Atlanta about 11:20 a.m. EDT. Brantly was “extremely stable” throughout the flight, according to the contractor that operates the plane.

After landing, Brantly was taken by ambulance to Emory’s hospital. There, a news helicopter captured one person in a head-to-toe protective suit — apparently Brantly — climbing out and walking slowly toward the hospital. He was aided by another person in protective gear.

“It was a relief to welcome Kent home today. I spoke with him, and he is glad to be back in the U.S.,” Amber Brantly, the doctor’s wife, said in a statement issued through the Christian charity Samaritan’s Purse. Kent Brantly was working for Samaritan’s Purse treating Ebola patients in Monrovia when he fell ill.

“I am thankful to God for his safe transport and for giving him the strength to walk into the hospital,” Amber Brantly said in the statement.

In this Ebola outbreak, about 60 percent of people who have contracted it have died. The disease’s first symptoms may not appear until 21 days later. But when they appear, they can be fearsome: fever, vomiting, diarrhea, massive internal and external bleeding, and multiple organ failure.

Ebola cannot be cured with medication. Instead, doctors seek to keep patients hydrated, and hope their bodies’ natural defenses can fight off the virus.

Health officials have said there is no reason for concern from others about the return of Brantly and Writebol to American soil. Both patients will be kept in strict isolation, and the Ebola virus is spread only through direct contact with an infected person’s bodily fluids, unlike other viruses that spread through the air.

“Ebola does not pose a significant risk to the U.S. public,” the Emory hospital said in a statement on Saturday.

Brantly and Writebol had been been treating Liberian victims of the largest Ebola outbreak in history. So far, the disease has sickened at least 1,323 people across four west African countries: Liberia, Guinea, Sierra Leone and Nigeria.

At least 729 patients have died, according to the World Health Organization.

The Ebola outbreak that emerged in March in West Africa has killed more than half the 1,300-plus people who have been infected, making it the deadliest outbreak ever. The virus, which causes severe bleeding and has no known cure, has been found in Guinea, Sierra Leone and Liberia.

Friends of Brantly’s have said the doctor had embraced the risks of practicing medicine in the developing world.

“He became a doctor in order to be a medical missionary,” said Kent Smith, an elder at Southside Church of Christ in Fort Worth, where Brantly attended for five years. “He was interested in being a missionary before he was interested in becoming a doctor.”

Smith said that Brantly — the father of two children — had originally intended to become a Christian missionary. But during his time as a student at Texas’ Abilene Christian University, Brantly went along as a helper with a group of doctors providing charity care in Central America.

He loved the work, Smith said, and then spent an extra year at the university to gather the right pre-med credits.

Brantly graduated from Indiana University’s medical school in 2009. He finished his medical training at John Peter Smith Hospital in Fort Worth, where he entered a program meant for doctors practicing in rural America or the developing world.

In recent days, Brantly had called and e-mailed friends with the devastating news that he had contracted Ebola while trying to help others fight it.

“He was tired and ill and weak, but otherwise in good spirits. He was calm and confident,” said David McRay, one of Brantly’s instructors in Fort Worth, who spoke to him on Monday by phone. McRay said Brantly was sustained by his Christian faith. Still, as a doctor, he knew what he was up against: “He was very aware of the implications of the Ebola virus. And very aware of the course that the illness could take.”

Brantly’s church learned of his illness the night of July 26, Smith said. At the next morning’s Sunday service, the pastor read out a prayer request relayed from Brantly himself.

“He wanted us to be sure and pray for his friend Nancy [Writebol], and for all the other Africans that were suffering from the virus, and he wanted us to specifically pray that God would be glorified through this ordeal,” Smith said.

Brantly’s wife and children had already left Africa before he became ill. They are now in Texas, under observation by state health officials. The family is now two-thirds of the way through a 21-day “fever watch.” So far, none of them have shown symptoms of the disease.

On Saturday, Brantly was brought back to the United States using a procedure designed about three years ago and intended to evacuate stricken Centers for Disease Control and Prevention workers from outbreaks overseas. A spokesman for contractor Phoenix Air, which provided the “air ambulance,” said the plan had been practiced repeatedly.

First, in Liberia, Brantly was brought on board a plane with a special room inside. The room is sealed, and kept at a lower air pressure than the surrounding cabin. That way, if there’s a leak, the air will leak in — not out. The intent is to keep airborne pathogens from spreading, although that is not a risk with Ebola patients.

“Remember: this is not designed for Ebola. This is designed for everything,” the spokesman for Phoenix Air said. Doctors and nurses remained with Brantly during the trip, the spokesman said.

After the plane arrived, CNN reported that Brantly’s wife, parents and sister cried when they saw the doctor walking from the ambulance into the hospital. CNN said Brantly’s family was expected to see him through a glass wall at Emory later Saturday.