Hours after the first patient to be diagnosed with Ebola in the U.S. died of the disease, health officials moved to ease public worries and protect Americans by instituting increased screenings for airline passengers arriving from West Africa.
Beginning at JFK airport on Saturday, and moving to four other airports next week, authorities will be questioning these travlers about potential Ebola contact and taking their temperatures, Dr. Tom Frieden, director of the Centers for Disease Control and Prevention, said in a Wednesday media conference.
"We are taking these additional measures in a dynamic environment to ensure a layered approach and that we take the security measures that we assess to be needed right now," Alejandro Mayorkas, deputy secretary of the Department of Homeland Security, said at the conference.
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About 150 travel daily to the United States from the three countries hit hardest by Ebola-Guinea, Liberia and Sierra Leone-Frieden said.
Roughly 94 percent of these airline passengers enter the country through either JFK, Washington-Dulles, Newark, Chicago-O'Hare, and Atlanta, so these five airports will be the focus of the increased screenings, the officials said.
Frieden also disclosed that authorities were evaluating a suspected Ebola patient, but that the CDC will not have any definitive information for a few hours.
"There is someone who does not have either definite contact with Ebola or definite symptoms of Ebola who is being assessed," Frieden said. "We expect that as people are more concerned, as there's a higher index of suspicion, people will be assessed, there will be rumors and concerns and potential cases, and that's as it should be. We should just keep it in perspective."
As of the Wednesday conference, none of the 48 people who definitely or potentially had contact with the now-deceased patient have developed any definite symptoms, Frieden said.
Thomas Eric Duncan, the first known person to develop Ebola in the United States, died Wednesday at Texas Health Presbyterian Hospital in Dallas. He was 42.
"It is with profound sadness and heartfelt disappointment that we must inform you of the death of Thomas Eric Duncan this morning at 7:51 am. Mr. Duncan succumbed to an insidious disease, Ebola. He fought courageously in this battle," a statement from Texas Health Resources said.
"Our professionals, the doctors and nurses in the unit, as well as the entire Texas Health Presbyterian Hospital Dallas community, are also grieving his passing. We have offered the family our support and condolences at this difficult time," the statement continued.
Although Duncan received the best care, Frieden indicated the patient's delayed treatment may have hurt his chances of survival.
"Ebola, even with the best of treatment, is a terrible disease, and is fatal in a high proportion of cases, and we encourage rapid and early diagnosis because the earlier someone is diagnosed, the more likely they'll be to survive," Frieden said.
The CDC confirmed Sept. 30 that Duncan tested positive for Ebola , quickly announcing to the public that it would be tracking down potential contacts alongside local officials.
Since then, authorities have identified 10 people who definitely came into direct contact with Duncan, and 38 possible contacts, Frieden said Tuesday.
The Dallas hospital has been criticized for turning Duncan away when he first came to their emergency room on Sept. 25 with symptoms and told them he was travelling from Liberia. That incident represented "a teachable moment," Frieden said Oct. 2.
According to authorities, Duncan arrived in Dallas on Sept. 20 from Liberia, and did not develop any symptoms for several days. Because of this, Frieden and others have said, he would not have been infectious during the flight.
Now officials will face the question of how to handle Duncan's remains. Doctors know that the body of someone who's just died of Ebola is dangerous: The virus can live in bodily fluids and tissue so long as they stay wet and room temperature. Many deaths have been linked to the handling of bodies in Liberia, Sierra Leone and Guinea.
The CDC recommends that anyone at the hospital who is handling the body of someone who died of Ebola must wear personal protective equipment., including a scrub suit, cap, gown over the suit, eye protection, face mask and two pairs of gloves. The body must be wrapped in a plastic shroud. It should not be washed. It must be put into a leak-proof plastic bag that zips closed, and then into another one right away. This whole package should be disinfected and then the room disinfected.
The body should then either be cremated or put into a hermetically sealed casket immediately so that family members can safely have a funeral, according to the CDC.
The current outbreak of Ebola, the worst ever recorded, has killed 3,879 people out of 8,033 cases as of Oct. 5, according to a Wednesday report from the World Health Organization. The situation in the most heavily affected countries-Guinea, Liberia, and Sierra Leone-"continues to deteriorate," the WHO report said.
The U.S., along with Brazil and Argentina, also announced that it has tightened procedures for allowing ships from West Africa into port.
-NBC's Maggie Fox contributed to this report.