Health screenings to help prevent the spread of Ebola began Saturday for some travelers to New York's John F. Kennedy International Airport but an official with the Centers for Disease Control and Prevention warned that nothing can "get the risk to zero."
Four other airports will add the screenings next Thursday, according to the CDC.
This won't be a mass event, with long lines of travelers waiting for screening. Only about 150 travelers a day will receive the screenings, CDC officials said.
"No matter how many of these procedures are put into place, we can't get the risk to zero," Dr. Martin Cetron, director of the CDC's Division of Global Migration and Quarantine, told reporters Saturday. "That will not be the case but this additional layer should add a measure of security to the American public. This entry screening procedure, for example, would not necessarily have caught the patient in Dallas."
Cetron was referring to the only case of Ebola so far diagnosed on U.S. soil -- that of Thomas Eric Duncan, who didn't have symptoms at the time he arrived in the United States.
Under the program, passengers originating from Guinea, Liberia, and Sierra Leone will be subject to the additional screening, according to the CDC.
Medical workers will take the passengers' temperature and Customs and Border Protection staffers will ask questions about their health and possible exposure to Ebola.
Those suspected of possible Ebola exposure will be referred to a CDC public health officer for additional screening.
After the initial run Saturday at JFK, the testing will expand Thursday to Washington-Dulles, Newark, Chicago's O'Hare International Airport and Hartsfield-Jackson International Airport in Atlanta.
The five airports, JFK included, receive 94% of air travelers that come from the afflicted countries, according to the CDC.
"The expanded screening measures provide this layer of protection to the already established protocols to minimize the risk of another case of Ebola here in the United States," said R. Gil Kerlikowske, commissioner of U.S. Customs and Border Protection.
Kerlikowske said travelers with fever or other symptoms or who were exposed to Ebola in one of the affected countries will be referred to the CDC assessment to determine whether they can travel or should be taken to a hospital. In addition, border patrol agents will monitor travelers for signs of illness.
Cetron said 100% of travelers leaving the affected countries are already being screened with risk questionnaires about possible exposure and symptoms and, in some cases, have their temperatures checked multiple times.
"More than 36,000 passengers have been screened with this tool the last two months and not a single Ebola case has been detected," he said. "As expected there have been some fevers and some with symptoms who were not permitted to board ... but most of these when evaluated were the more common expected causes like malaria."
Will it help?
Some critics of the U.S. approach say the screenings won't do much from a public health perspective.
"I think they offer some margin of, I don't know, peace of mind for the public," said Laurie Garrett, a senior fellow for global health at the Council on Foreign Relations and author of "The Coming Plague."
But she stressed that the screenings would not have detected Duncan's case.
"So I see this more as something to calm the nerves of the American people, the British people, the French people and so on, rather than actual screening," she said.
Mary Schiavo, a former inspector general for the U.S. Department of Transportation, said the effort isn't "entirely window dressing, because we have to do something"
"But," she said, "there's much more that has to be done to keep people safe."
She says she worries about planes that carry ill passengers who may not be detected until after they get off the flight. By then, the plane may have already been prepared for another flight.
"They have to put in place some way to detain the plane, and that hasn't been done yet," she said.
Public health officials have warned the screenings will likely catch some people who have fevers, but not Ebola, and could miss some with Ebola as symptoms can take up to 21 days to appear.
"No exit or entry screening will supplant the need for state and local health departments, for clinicians and for individuals to be aware and to think Ebola... if they have the signs and symptoms or fever and they've been in the affected area in the previous 21 days," Cetron said.
Ebola worries spread
In New York, fire officials said a patient in Brooklyn with Ebola-like symptoms had recently returned from the North African country of Sudan, the New York Daily News reported.
The patient was was undergoing tests, but the New York Health Department told CNN Friday that there were no patients in the city suspected of having Ebola.
Sudan is far-removed from the West African center of the outbreak -- as far away from it as Atlanta is from Los Angeles. Still, fear of the often deadly disease has bred much caution.
"I have seen several people who had acute illnesses worried that they may have Ebola," said Dr. Mark Reiter, an emergency room physician in Tennessee and president of the American Academy of Emergency Medicine.
Reiter says many patients in his state are unlikely candidates, not having been to West Africa, nor having had any contact with a symptomatic Ebola patient.
"But it has gotten a tremendous amount of media coverage and some people are especially concerned about it, even if it is highly unlikely," Reiter said.
Outbreak in Africa
At least 8,399 people are believed to have contracted the disease as of October 7, according to the World Health Organization. Of those, 4,033 have died, the agency said.
Among health care workers fighting the outbreak, 416 are believed to have caught the disease and 233 have died, according to WHO.
The numbers were reported from Guinea, Liberia, Nigeria, Senegal, Sierra Leone, Spain and the United States.
Aid workers Nancy Writebol and Dr. Kent Brantly contracted the disease in Liberia while working with Samaritan's Purse to care for Ebola patients. They were flown to Emory Hospital in Atlanta, where they were treated and released in August after doctors concluded they were healthy and posed no public health risk.
A third patient, Dr. Rick Sacra, was flown to Omaha, Nebraska, after contracting the disease while working for another aid group in Liberia. He survived and was discharged in September.
Doctors at the same hospital are now caring for Ashoka Mukpo, an NBC News videographer diagnosed with Ebola on October 2.
Authorities had to impose a mandatory quarantine on NBC News staffers who worked with Mukpo after they violated a voluntary quarantine, New Jersey health officials said.
He was among a team working with Dr. Nancy Snyderman, the news agency's chief medical correspondent.
"The NBC crew remains symptom-free, so there is no reason for concern of exposure to the community," said Donna Leusner, a spokeswoman for the New Jersey Department of Health.
Duncan, the sole person to be diagnosed with the virus on American soil, died this week. His nephew has raised questions about his care, saying that because he was black, poor and without insurance he didn't get the same care as other victims in the United States.
The Dallas hospital who treated him has defended its care, saying its staffers are "committed to providing the best possible care to every patient we see."
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