(CNN) -- Thomas Eric Duncan, a man with Ebola who traveled to the United States from Liberia, died Wednesday morning at Texas Health Presbyterian Hospital in Dallas, the hospital said.

He had been in critical condition after being diagnosed with the virus in mid-September. People who have had contact with the Liberian national are being monitored for symptoms.

It has just been a little over a week since Duncan began receiving treatment for the virus, and those days have spelled an "enormous test of our health system," said Dr. David Lakey, the commissioner of the Texas Department of State Health Services.

"For one family it has been far more personal," he said in a statement. "Today they lost a dear member of their family. They have our sincere condolences, and we are keeping them in our thoughts."
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He vowed that health care workers will continue to try to stop the spread of the virus "and protect people from this threat."

The Ebola virus can live in dead bodies, the U.S. Centers for Disease Control and Prevention says, and it can be transmitted after death if the body is cut, body fluids are splashed, or if the body is handled. Only personnel trained in handling infected human remains, wearing protective gear, should touch or move Ebola-infected remains, the agency says. An autopsy should be avoided, it says, but if one is necessary, the CDC should be consulted.

Airport screenings

News of the death of the first Ebola patient diagnosed in the U.S. comes as a federal official told CNN that airports in the United States will begin taking the temperatures of arriving passengers who have flight itineraries originating from West African countries where Ebola is concentrated.

The screenings will begin this weekend or next week, according to the source who has direct knowledge of the screenings.

Among the countries considered to be in the so-called Ebola zone are Guinea, Sierra Leone, Liberia and Nigeria.

The new measures at U.S. airports come a day after Dr. Thomas Frieden, the director of the CDC, told reporters that devising travel guidelines was in the works but nothing had yet been finalized enough to announce.

Can you catch Ebola on a plane?

The Ebola virus can spread through contact with bodily fluids -- blood, sweat, feces, vomit, semen and saliva -- and only by someone who is showing symptoms, according to the CDC.

People with Ebola may not be symptomatic for up to 21 days.

Symptoms generally occur abruptly eight to 10 days after infection, though that period can range from two to 21 days, health officials say.

Air travelers must keep in mind that Ebola is not transmitted through the air, said Dr. Marty Cetron, director of the CDC's Division of Global Migration and Quarantine.

"There needs to be direct contact frequently with body fluids or blood," he stressed.

Cases in Europe

Meanwhile, Frederic Vincent, a spokesman for the European Commission, told CNN on Wednesday that there have been eight confirmed cases of Ebola in European countries. There is one case in the United Kingdom that has been treated and the person has recovered; one case in France like that; two cases in Germany in which patients are receiving treatment; and three cases in Spain: two deceased Spanish missionaries and a nurse's assistant who is being treated.

There is also a case in which a Norwegian staffer with Doctors Without Borders is being treated, he said.

Also in Spain, health officials said four more potential Ebola cases -- in addition to the nurse's assistant -- are under observation.

The nurse's assistant said that she had no idea how she had contracted the virus, but a doctor treating her said that she may have been exposed while she removed her protective suit.

Dr. German Ramirez said the assistant, who is in isolation at Madrid's Carlos III Hospital, had told him it was possible that a part of the suit -- possibly the gloves -- touched her face.

Cases in West Africa

The globe's largest outbreak of Ebola has killed more than 3,400 people in Guinea, Liberia and Sierra Leone. Since March, more than 7,400 people have contracted Ebola in those nations, according to the World Health Organization.

The CDC is tracking the latest cases in the region.

NBC News freelance cameraman Ashoka Mukpo was diagnosed with Ebola in Liberia on Thursday. He left Liberia on a specially equipped plane Sunday and was headed to Nebraska, the network reported.

Frieden said Tuesday that battling the virus will be a "long, hard fight."

"The virus is spreading so fast," he said, "that it's hard to keep up."

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