DALLAS - Two days after he was sent home from a Dallas hospital, the man who is the first person to be diagnosed with Ebola in the United States was seen vomiting on the ground outside an apartment complex as he was bundled into an ambulance.
The Dallas Ebola case, involving a man who flew back to the United States last month from Liberia, has prompted national concern over the potential for a wider spread of the deadly virus from West Africa, where at least 3,338 people have died in the worst outbreak on record.
US health officials have said the country's healthcare system is well prepared to contain any spread of Ebola through careful tracking of people who had contact with the patient and appropriate care for those admitted to hospital.
"His whole family was screaming. He got outside and he was throwing up all over the place," resident Mesud Osmanovic, 21, said on Wednesday, describing the chaotic scene before the man was admitted to Texas Health Presbyterian Hospital on Sunday where he is in serious condition.
The hospital cited the stricken man's privacy as the reason for not identifying him. However, Gee Melish, who said he was a family friend, identified the man as Thomas Eric Duncan.
The New York Times said that Duncan, in his mid-40s, helped transport a pregnant woman suffering from Ebola to a hospital in Liberia, where she was turned away for lack of space. Duncan helped bring the woman back to her family's home and carried her into the house, where she later died, the newspaper reported.
Four days later Duncan left for the United States, the Times said, citing the woman's parents and neighbours.
Texas health officials said that up to 18 people, including five children, had contact with the Ebola patient since he returned to the United States in late September. The children had gone to school early this week but have since been sent home and are being monitored for symptoms.
Ebola spreads through contact with bodily fluids such as blood or saliva, which health experts say limits its potential to infect others, unlike airborne diseases.
Still, the long window of time before patients exhibit signs of infection, such as fever, vomiting and diarrhoea, means an infected person can travel without detection.
Airline and hotel company shares dropped sharply on US markets on Wednesday over concerns that Ebola's spread outside Africa might curtail travel.
Drugmakers with experimental Ebola treatments in the pipeline saw their shares rise.