US Ebola victim arrives at Emory University hospital in Atlanta

• Dr Kent Brantly on plane which left Liberia on Saturday
• Missionary Nancy Writebol due to fly in soon

An ambulance transporting Dr Kent Brantly, who is infected with the Ebola virus, arrives at Emory University Hospital in Atlanta. Photograph: Erik S Lesser/EPA

One of two American aid workers infected with the deadly Ebola virus returned to the US from Africa on Saturday. Both were volunteers treating Ebola patients in Liberia, one of three countries affected in a West African outbreak that has so far killed 729 people, the deadliest outbreak in history.

Dr Kent Brantly of Texas was transported to the Emory University hospital in Atlanta, where he will be quarantined in a sophisticated isolation unit. He returned to the US in a private jet outfitted with a containment tent.

Transport of the second aid worker, the South Carolina missionary Nancy Writebol, is expected to be completed early in the week. She is also expected to be treated at Emory. Writebol is travelling later because the jet is only designed to carry one patient at a time.

Brantly arrived in the US at Dobbins Air Force Base in Marietta, Georgia, and was driven by ambulance to the hospital, about 15 miles away. At the hospital, one person in protective clothing guided another, believed to be Brantly, towards a building. The ambulance was flanked by SUVs and police cars. About 20 members of the media were present at the hospital. There was no noticeable police presence and all roads were open.

“Thank you to our good friends and thousands more who have been in constant prayer and fasting for Kent’s deliverance from this disease,” Brantly’s wife, Amber, said in a statement. She and the couple’s children were living in Liberia with Brantly but left before he developed symptoms.

“Our kids have been a welcome relief and distraction to us all, reminding us of our joy and hope,” Amber Brantley said.

Brantly and Writebol contracted the disease while working for a Christian aid organisation, Samaritan’s Purse, which is now evacuating “all but the most essential personnel to their home countries”.

Doctors believe Ebola is passed from wild animals to humans through blood and other bodily fluids, and then from human to human through bodily fluids. The disease caused by the virus, EVD, has no cure or vaccine and kills up to 90% of those infected depending on the strain, according to the World Health Organization.

Ebola can cause severe internal bleeding and is sometimes referred to as haemorrhagic fever. Symptoms include weakness, diarrhoea, vomiting and muscle aches, as well as internal and external bleeding.

Treatment is usually confined to “supportive therapy”, in which doctors monitor blood pressure and administer intravenous fluids and oxygen. Some experimental treatments have proven effective in animals, but no treatments approved for use in humans exist.

Although some have expressed fear at returning Ebola patients to the US, doctors believe there is little risk of transmitting the virus in western healthcare settings.

“I want to underscore that Ebola poses little risk to the US general population,” said Dr Stephen Monroe, head of the Centres for Disease Control’s National Centre for Emerging Zoonotic and Infectious Diseases, in a press call last week. “While it’s clear there is an increased risk for working with patients with Ebola, we’re confident that the standard of care in the US would prevent much of the transmission if a case were to show up here.”

Dr Jay Varkey, an infectious disease specialist at Emory, told the Associated Press the hospital’s isolation unit was well-equipped to handle patients with diseases even more infectious than Ebola, having been used for treating at least one Sars patient in 2005. Unlike Ebola, Sars is an airborne virus and can spread easily when an infected person coughs or sneezes.

Experts say a specialised isolation unit is not needed for treating an Ebola patient and that standard rigorous infection control measures should work at any hospital.

Dr Kent Brantly working at an Ebola treatment clinic in Foya, Liberia, in June. Photograph: Samaritan’s Purse/EPA

Many say that efforts to contain the disease in Africa are hindered by poor healthcare infrastructure.

“As you might imagine, the kinds of mechanical support and other things available in these clinics in Africa is fairly rudimentary,” said Monroe. “Most of the potential exposure to patients is through … needle sticks and things like that in collecting specimens and in disposing of bodily fluids if the patients have vomiting or diarrhoea.”

On Thursday, the CDC heightened its warning against “nonessential travel” to Guinea, Liberia and Sierra Leone, where the outbreak is concentrated. The CDC is also assisting with screening passengers before they board planes.

“This is the biggest and most complex Ebola outbreak in history. Far too many lives have been lost already,” said the CDC director, Dr Tom Frieden, in a statement on Thursday, announcing a surge in CDC workers to the three African nations. An additional 50 disease control experts will arrive in the region in the next 30 days.

“It will take many months, and it won’t be easy, but Ebola can be stopped,” Frieden added. “We know what needs to be done.”