ATLANTA — An American doctor infected with the Ebola virus in Africa arrived in Atlanta for treatment Saturday, landing in a specially equipped plane at a military base, then being whisked away to one of the most sophisticated hospital isolation units in the country, officials say.

It marks the first time anyone infected with Ebola, considered one of the world’s deadliest diseases, is believed to have been brought into the country for treatment. A second American aid worker infected with the virus was expected to arrive at Emory within a couple days. U.S. officials are confident the patients can be treated without putting the public in danger.

The private plane outfitted with a special, portable tent designed for transporting patients with highly infectious diseases arrived late morning at Dobbins Air Reserve Base, spokesman Lt. Col. James Wilson confirmed. U.S.-based Samaritan’s Purse missionary group, which paid for the transport, told The Associated Press that Dr. Kent Brantly is the patient.

An ambulance from Atlanta’s Grady Memorial Hospital left the base in Marietta, Georgia, shortly after the Gulfstream landed and drove the 15 miles or so toward Emory University Hospital where Brantly and another aid worker will be treated.

The ambulance with red markings was under light security, flanked by a few SUVs and a police car for the short trip to the hospital along a wide-open Interstate with no traffic.

Once at the hospital, a person in white protective clothing from head to toe climbed down from the back of the ambulance and another person in the same type of hazmat-looking suit appeared to take his gloved hands and guide him toward a building at Emory. The hospital is located just down a hill from the Centers for Disease Control and Prevention.

The second patient, Nancy Writebol, will be brought from Africa soon, the hospital has said. The two Americans worked for North Carolina-based Samaritan’s Purse and U.S.-based SIM at a Liberian hospital that treated Ebola patients. Liberia is one of the three West Africa countries hit by the largest Ebola outbreak in history.

Dr. Jay Varkey, an infectious disease specialist at Emory who will be involved in Brantly’s care, said the hospital’s isolation unit is well-equipped to handle patients with diseases that are even more infectious than Ebola.

The unit was used for treating at least one SARS patient in 2005. Unlike Ebola, SARS — like the flu — is an airborne virus and can spread easily when an infected person coughs or sneezes. Health experts say a specialized isolation unit is not needed for treating an Ebola patient. Standard rigorous infection control measures should work at any hospital.

“Ebola is only transmitted through blood and bodily fluids,” he said. “Unlike the flu, like influenza, which we deal with every winter, Ebola cannot be spread thorugh the air.”

Ebola begins with fever, headache and weakness and can escalate to vomiting, diarrhea and kidney and liver problems. In some cases, patients bleed both internally and exter