The man who became the first person to be diagnosed with Ebola in the U.S. on Tuesday was seen vomiting outside his Dallas apartment building as paramedics ushered him into an ambulance Sunday. "His whole family was screaming. He got outside and he was throwing up all over the place," neighbor Mesud Osmanovic, 21, told Reuters on Wednesday.

The patient, Thomas Eric Duncan, was visiting his sister in Dallas from his native Liberia in West Africa, where the Ebola virus has killed more than 3,000 in an outbreak this year. He went to an emergency clinic on Friday after feeling ill for two days, but was sent home with antibiotics. On Sunday, he was rushed to the hospital. 

Ebola spreads through bodily fluids like blood and vomit but not through the air. Up to 18 people who came into contact with Duncan, including five children, are being monitored for symptoms, Texas health officials said.