A top federal health official said Monday that the diagnosis of a Dallas nurse with Ebola—the first case to be transmitted in the U.S.—"does change substantially how we approach" the virus.
"We have to rethink the way we address Ebola infection control because even a single infection is unacceptable," said Dr. Thomas Frieden, director of the Centers for Disease and Control, during a briefing from Washington, D.C.
The nurse, based at the Texas Health Presbyterian Hospital where Liberian national Thomas Eric Duncan eventually died from the virus last week, reported a low grade fever Friday night and was isolated.
A family friend who spoke with NBC News later identified the nurse as 26-year-old Nina Pham—Frieden did not name her during his briefing.
"I feel awful that a health-care worker became infected in the care of an Ebola patient," Frieden said "She was there trying to help the first patient survive and now she has become infected. All of us have to work together to do whatever is possible to reduce the risk that any other health care worker becomes infected."
Frieden said a CDC team and the hospital are investigating how Pham contracted the virus from Duncan, as well as working to interview and monitor the "large" number of health-care workers that may also have had contact with Duncan.
"We need to consider the possibility that there could be additional cases," Frieden said, several hours before President Barack Obama was scheduled to be briefed about the ongoing response to Ebola by his administration.
Frieden said the team is also evaluating how to make changes in the way staff members are treating such patients and how they can protect themselves to avoid future transmissions. Workers are being watched as they go in and out of the isolation unit—to see how they put on and remove their protective gear—where the infected nurse is being treated.
Frieden also said the team is "looking at the protective equipment that is used," and is examining the possibility of spraying workers down with a substance that could neutralize the deadly virus.
He said officials would "double-down" on training, outreach, education and assistance for health-care systems and workers nationwide to increase awareness of Ebola and know how to rapidly response to suspected cases. In particular, he noted, patients should be isolated immediately if they have a fever and if they been in West Africa in the past 21 days.
"Stopping Ebola is hard," he said. "We're working to make it safer and easier."
However, he noted, "we don't know" how the nurse became infected. Frieden said that Pham, who is "clinically stable," has been answering questions from others about her movements while dealing with Duncan's case.
Officials already were monitoring 48 people who had or may have had contact with Duncan before he was admitted to the hospital in late September, Frieden said.
"We have identified one and only one [person] who had contact with" the health-care worker when she was potentially, but unlikely infectious with Ebola, he said.
"That individual is now being monitored and as of now has no symptoms," Frieden said.
Officials also will be monitoring the health-care workers who dealt with Duncan. Pham, the nurse, was not among the 48 people whom officials were originally monitoring.
"We have to case a net more widely in terms of monitoring a larger portion of health-care workers," he said.
Pham's dog also is being monitored for signs of Ebola. An initial cleaning of ther apartment has been done, and a follow-up evaluation and cleaning is being done Monday.
The city of Dallas also made reverse 911 calls to residents of the area where Pham lives informing that that, "a health-care worker who lives in your area, has tested positive for the Ebola virus."
"This individual is in the hospital and is isolated. Precautions are already in place to clean all known potential areas of contact, to ensure public health. While this may be concerning, there is no ongoing danger to your health," the calls said. "The virus does not spread through casual contact."
Frieden reiterated that the Obama administration will not, as some have called for, ban travel from the West African countries that are the center of the current outbreak.
"Whatever we do, we're not going to limit travel from this countries," said Frieden, noting that such a ban would make it hard to get medical personnel and equipment into those countries, and could lead to the further spread of the virus.
Shortly before Frieden spoke, Canada's health minister announced the country's potential Ebola vaccine will start being tested on humans at the Walter Reed Army Institute of Research in Silver Spring, Maryland.
The drug, which has been licensed by NewLink Genetics, will start testing "on a small group of people to assess its safety, determine the appropriate dosage and identify any side effects," according to a press release. NewLink stock jumped sharply on the news, closing the day at $22.42 per share, up 23.66 percent from the previous day.
The results of the so-called Phase 1 trial are expected in December. Canada has supplied 20 vials of the experimental vaccine for the test.
Scientists who have already tested the experimental drug on animals "have seen positive results in the development of the Ebola vaccine to date," said Steven Guercio, acting director general of the National Microbiology Laboratory of Canada.
No drug has been approved as of yet for either a vaccine or treatment.
Last week, another leading federal health official said an Ebola vaccine would likely have been available sooner but for a decade-long series of federal budget cuts.
The National Institutes of Health "has been working on Ebola vaccines since 2001. It's not like we suddenly woke up and thought, 'Oh, my gosh, we should have something ready here,' " NIH director Dr. Francis Collins, told The Huffington Post in an article posted Sunday.
"Frankly, if we had not gone through our 10-year slide in research support, we probably would have had a vaccine in time for this that would have gone through clinical trials and would have been ready."
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With proper funding, "We would have been a year or two in ahead of where we are, which would have made all the difference," Collins told The Huffington Post.
The death toll in West Africa has topped 4,000. He added that even the current Ebola outbreak—the worst in history—hasn't led to more funding for NIH. Instead, it's taking money budgeted for other things and redirecting them to the Ebola effort.
NIH's budget has barely grown in actual dollar terms since 2004, when it stood at $28.03 billion. The agency's 2013 budget was $29.31 billion, which after accounting for the effects of inflation, is 23 percent lower in purchasing power, the article said.
Collins said NIH researchers are rushing and "cutting corners" to develop a vaccine, but it could take until spring to find out if its current experimental drug is effective.
That drug is being developed jointly with British-based drug giant GlaxoSmithKline. A top GSK executive recently told CNBC that it could take between 12 and 18 months to produce that vaccine in mass quantities if it proves effective. Another potential vaccine is in development, by Johnson & Johnson.
At least four potential Ebola treatments are available, produced by Mapp Biopharmaceutical, Tekmira Pharmaceuticcals, Sarepta Therapeutics and Chimerix. The drugs produced by Chimerix, Mapp and Tekmira all have been used on an emergency basis in a handful of current cases.
Collins said although the disease is rapidly spreading in West Africa, he does not expect it to spread in the U.S.
"How many more people will get infected with Ebola this year in the U.S.?" Collins said. "I would guess you could count among the fingers of two hands, depending on what contacts of the guy in Dallas actually turned out to get infected.
Meanwhile, New York's John F. Kennedy International Airport began screening for Ebola over the weekend. Four other U.S. airports this week will begin screening for Ebola, focusing on travelers arriving from the three counties worst hit in this outbreak: Guinea, Liberia and Sierra Leone.
British health-care officials on Monday said that similar screening will begin at London's Heathrow airport on Tuesday, and later this week at another local airport, Gatwick, as well as terminals of the Eurostar train line.
In Louisiana, the state attorney general vowed to take legal action to block plans to dispose of the incinerated belongings of Duncan, the Dallas Ebola victim, in a landfill in that state.
After his announcement, Waste Management, Inc., which operates the landfill in Lousiana, in a press release said it has informed the Texas facility handling those belongings that "it has no current plans to accept ash resulting from the process to incinerate some decontaminated belongings from an Ebola patient's apartment located in Dallas, Texas."
"While the CWM-LC facility is permitted by the state and federal government to accept waste of this type, and while accepting this waste poses no threat to the environment or human health, we do not want to make an already complicated situation, more complicated," Waste Management said.