A US doctor infected with the deadly Ebola virus in Liberia has arrived in the US for treatment at a specialised unit in Atlanta, Georgia.
Dr Kent Brantly arrived in a specially equipped private plane at a military base before being driven to Emory University Hospital.
Fellow infected US aid worker Nancy Writebol is expected to follow shortly.
Ebola has claimed 728 lives in Guinea, Liberia and Sierra Leone this year. The current mortality rate is about 55%.
The virus spreads through human contact with a sufferer's bodily fluids.
Initial flu-like symptoms can lead to external haemorrhaging from areas like eyes and gums, and internal bleeding which can lead to organ failure.
The US health authorities have warned against travelling to the African states affected and 50 extra American specialists are being sent to affected areas.
The plane carrying Dr Brantly was outfitted with a special portable tent designed for transporting patients with highly infectious diseases.
After it touched down at Dobbins Air Reserve Base, the patient was collected by an ambulance which drove him to Emory, 15 miles (24km) away.
At the hospital a person in protective clothing could be seen climbing down from the back of the ambulance and a second person in protective clothing appeared to take his gloved hands and guide him toward a building, the Associated Press report.
US officials say they are confident the patients can be treated without putting the public in any danger.
The specialised unit was opened 12 years ago to care for federal health workers exposed to some of the world's most dangerous germs.
While it has an isolation unit, health experts say it is not needed for treating a patient with Ebola, as the virus does not spread through the air.
The US Centers for Disease Control and Prevention is unaware of any Ebola patient ever being treated in the US before.
Dr Brantly's employer, the aid group Samaritan's Purse, said in a statement that it was evacuating 60 non-essential staff who were healthy back to the US.
An earlier statement said that Dr Brantly had been offered experimental serum but he had insisted that Ms Writebol should receive it instead.
The doctor also received a blood transfusion from a boy who recovered from Ebola in his care, the Wall Street Journal reports.
Amber Brantly, his wife, said in a statement she remained "hopeful and believing that Kent" would be "healed from this dreadful disease".
"There is a little bit of worry," Jenny Kendrix, 46, told Reuters news agency when asked about having the Ebola virus patient brought to the same hospital where her husband was being treated for cancer. "There is worry about it getting out."
But Ernie Surunis, 52, at the hospital for a pharmacy conference, said he was not bothered at all.
"This is a good hospital," he said. "I'm glad [the patients] are coming. We can't leave them [in Africa] to die. They went over to help other people."
The National Institutes of Health in the US has said it will begin testing a possible Ebola vaccine in September.
Ebola since 1976
Ebola virus disease (EVD)
- Symptoms include high fever, bleeding and central nervous system damage
- Fatality rate can reach 90%
- Incubation period is two to 21 days
- There is no vaccine or cure
- Supportive care such as rehydrating patients who have diarrhoea and vomiting can help recovery
- Fruit bats are considered to be virus' natural host