Washington: Health officials in Texas on Thursday were monitoring 100 people for signs of Ebola and ordered four close family members to stay home as authorities investigate the first confirmed US case of the disease.
The patient, who was identified in US media as Thomas Eric Duncan, traveled from Liberia to Texas, where was diagnosed earlier this week.
He did not have a fever when he departed Liberia on September 19, said Centers for Disease Control and Prevention chief Tom Frieden.
However, he began to feel sick on September 24, and once a patient begins to show symptoms like fever, vomiting and diarrhea, they can infect others who come in close contact with their bodily fluids.
He was initially sent home when he first sought medical care, leaving a four-day span when he was sick and contagious while in contact with others, sparking concern over how many others may have been exposed.
About 100 people who had potential contact with Duncan are being assessed, said Frieden.
"We have interviewed most of those people, but far from all," Frieden told reporters on a conference call, the first of a series of daily briefing the agency will hold now that Ebola has arrived on US soil.
"We have identified a handful of people who may have had exposure," he said, adding that they were "people from the household and healthcare settings as well."
Fourteen people have so far tested negative, he added.
United Airlines, which operated two of the flights Duncan took to reach Texas, has also issued a statement with flight details, suggesting any concerned passengers contact the CDC, though the company stressed that officials say there was "zero risk of transmission" at the time.Meanwhile, four family members will be legally required to stay home without visitors until October 19.
Their apartment is being guarded by a law enforcement officer.
As of midday Thursday, officials had been unable to find any cleaning or maintenance service to take away a garbage bag that held the sheets that were on Duncan`s bed when he was sick. The mattresses on which he lay had been pushed against a wall, Texas authorities said.
"The house conditions need to be improved," said David Lakey, Commissioner of the Texas Department of State Health Services.
"We have been working to identify an entity that will go out there and do the cleaning," he said, adding "there has been a little bit of hesitancy" on the part of cleaning companies that have been sought to take the items away.
Those in the apartment will also be required to provide blood samples, agree to any health testing, and report any symptoms of Ebola, including fever, muscle aches, vomiting and diarrhea.
"They do not have fever at this time. They are healthy. There is no risk that they have spread disease to any other individual," Lakey said.
A person can become sick with Ebola between two and 21 days after exposure.
Duncan`s nephew, Josephus Weeks, told NBC News on Wednesday that he called the CDC on September 28 over concerns his uncle was not getting proper care.
Frieden told reporters Thursday, "we are not aware of the family having contacted CDC but we are looking into that."
An official at the hospital where Duncan is being treated said the patient had told a nurse at his first exam on September 26 that he had recently traveled to Africa, which, coupled with his symptoms, should have immediately prompted the hospital to consider Ebola.
"Regretfully, that information was not fully communicated throughout the full team," said Mark Lester, executive vice president of Texas Health Resources, and the patient was sent home because the medical team "felt clinically it was a low-grade common viral disease."
West Africa is struggling to contain the world`s largest outbreak of the deadly hemorrhagic virus in history, which has taken more than 3,300 lives already this year.