(Above image: Thomas W. Geisbert, Boston University School of Medicine - PLoS Pathogens, November 2008, Color-enhanced electron micrograph of Ebola virus particles.)
First published Oct. 15, 2014
- More U.S. Ebola cases expected
- Infectious disease experts challenge CDC view that Ebola is "not airborne"
- Public health official worries about "The Tylenol Scenario"
With today’s announcement of a third Ebola victim in the United States—two of the cases transmitted on American soil—the words of a government health adviser resonated. Asked last week whether there would be more cases in the U.S., the official declared: “It’s inevitable.”
Just last week, on Oct. 8, Centers for Disease Control (CDC) Director Dr. Thomas Frieden had faced the press in an attempt to portray a sense of confidence and control.
It was a tall order.
A 45-year old Liberian man named Thomas Eric Duncan had just died from Ebola at a Dallas hospital. That was followed by news Sunday that one a nurse who treated Duncan, 26-year old Nina Pham, tested positive for Ebola. Then, today came news of a second female health care worker who treated Duncan becoming ill. Unfortunately, she flew on a Frontier airlines plane to Ohio. Officials tried to reassure the public that the latest snafu--U.S. airplane travel by an infected patient--posed little risk to others.
After $9 billion in federal money distributed to U.S. public health departments since 2002 for emergency preparedness, after widespread publicity about West Africa’s outbreak since last March, after reassurances that the world’s best and most modern health care system would keep Ebola out of the U.S., Duncan managed to carry the deadly virus deep into the heart of Texas by defying the honor system designed to stop it: He simply denied his contact with an Ebola patient in Liberia.
What followed would be considered a comedy of errors if not so tragic. Once in the U.S., Duncan became ill. He went to a Dallas hospital where officials say he again denied contact with Ebola patients. Though his chart noted his recent travel to Ebola-stricken Liberia, he was improperly sent home with antibiotics where he had contact with dozens of people until his condition became grave. Once deathly ill, he returned to the hospital and infected at least two health care workers.
At the press conference shortly after Duncan’s death, Dr. Frieden—carefully enunciating his words as if to exude an air of confidence and control—assured Americans that new measures will prevent Ebola from becoming a public health emergency in the U.S.
“The bottom line here is that we're stepping up our efforts to protect Americans,” Dr. Frieden said. “We will do everything we can both to stop it at the source and to protect Americans here.”
The irony seemed lost on the CDC director that the stepped up efforts do nothing to address another patient like Duncan. They include checking for fevers in most—but not all—arriving passengers from three West African nations. (But Duncan had no fever when he arrived.) Those with fevers will be questioned about their potential Ebola exposure. (But Duncan allegedly lied twice when queried about his).
“This entry screening procedure… would not necessarily have caught the patient in Dallas," CDC’s Global Migration and Quarantine director Martin Cetron admitted to reporters in a press briefing Saturday.
That CDC would address Duncan’s health security breach by belatedly installing measures that would not have prevented it is symptomatic of the botched response that has done much to confuse ordinary Americans as well as some physicians and infectious disease specialists.
Scores of passengers from West Africa have been allowed to enter the U.S. unchecked after the stepped up measures were announced last week but before they took effect Saturday at the busy John F. Kennedy International airport in the center of nation’s most populous city: New York. Four other major U.S. airports won’t begin the new screenings until tomorrow. And officials say 5-10% of passengers from at-risk nations will arrive at airports that won’t have the special screenings in place at all.
If Ebola continues to spread in the U.S., experts say overseas screenings will matter little.
Meantime, the CDC said it has advised airlines that may carry infected passengers on how to clean their airplanes after an Ebola passenger is discovered. But it apparently found no wisdom in asking them to clean their planes between flights before the next Ebola passenger is identified.
And Obama administration officials say they’ve given no consideration to restricting the relatively small number of incoming travelers from affected nations because that would only make matters worse. Today, former U.S. Surgeon General Richard Carmona said a travel ban should be considered.
Mode of Transmission: Uncertain?
The CDC continues to insist Ebola isn’t airborne, leaving the impression that there’s no risk to being near infected patients, as long as they or their body fluids are not touched.
But there is sharp disagreement among experts on this critical issue. A commentary published last month by the Center for Infectious Disease Research and Policy at the University of Minnesota highlights the points of contention.
In the article, national experts on respiratory protection and infectious disease transmission say the CDC may be wrong. They say CDC’s protocol of masks, gloves and gowns isn’t enough to protect health care workers treating Ebola patients: they should be equipped with respirators.
“It's imperative to favor more conservative measures,” say the authors.
“We believe there is scientific and epidemiologic evidence that Ebola virus has the potential to be transmitted via infectious aerosol particles both near and at a distance from infected patients, which means that healthcare workers should be wearing respirators, not facemasks.”
According to the article, “The precautionary principle—that any action designed to reduce risk should not await scientific certainty—compels the use of respiratory protection for a pathogen like Ebola virus that has: No proven pre- or post-exposure treatment modalities, A high case-fatality rate, Unclear modes of transmission.”
In fact, the experts argue, the very term CDC is using, “airborne,” is outmoded.
They explain that modern research shows that aerosols emitted from the respiratory tract contain a wide distribution of particle sizes—including many that are small enough to be inhaled.
“We recommend using ‘aerosol transmissible’ rather than the outmoded terms ‘droplet’ or ‘airborne’ to describe pathogens that can transmit disease via infectious particles suspended in air,” write the authors.
So far, the CDC is sticking with its terminology and position, insisting Ebola is not airborne.
Flaws in the Honor System
The weakest link in the prevention chain, say some experts, may be CDC’s reliance on exposed patients’ self-monitoring, honesty and altruistic motives.
To date, federal officials have utterly failed to publicly address the fundamental and potentially fatal flaws in such a system. Duncan’s case is one such example. The instance of NBC News TV doctor Nancy Snyderman is another: she got caught breaking her own voluntary Ebola quarantine to get take-out food. And today's news that a nurse under voluntary quarantine flew from Dallas to Ohio while infected is further evidence of serious flaws.
There are countless other scenarios unaddressed by the CDC’s plans: sick patients who may use poor judgment and fail to quarantine themselves in a timely basis, sick patients who may recognize their illness but expose dozens of people between their first fever symptom and the time they make it to the hospital and terrorists or others who wish to do harm getting possession of infectious waste from a patient.
A well-respected medical doctor who has advised the government on public health crises told me, “I’m more worried about people who are sick, want to come to the U.S. [for treatment] and take Tylenol before their flight to get to the U.S. so they won’t show a fever.”
In other words, a simple fever-reducing medicine could easily defeat the CDC’s best attempts to catch infectious patients upon their arrival at U.S. airports.
Flu Season Concerns
CDC officials continue to brace the American public to expect more cases. One official told me he fears there will be “a real mess” when flu season arrives and “everybody with a fever is going to think they have Ebola.” At first, it will be relatively easy to separate out those who haven’t had exposure via travel to West Africa. But as more cases crop up in the U.S., as many expect, then it will not be simply a matter of asking about their overseas travel.
The first case at Dallas Texas Health Presbyterian Hospital has already overwhelmed resources. Multiply that times five—or a hundred—and a situation that seems relatively minor could quickly spiral out of control, say experts.
Some public health officials are speaking in less comforting terms behind the scenes than they are in public. One official said of the Ebola in West Africa, “Things are much, much worse than the press is reporting. It’s affecting more people and it’s not under control. This epidemic is not under control.”
Similar warnings are echoed by medical experts in the medical journal Lancet.
“Failures in leadership have allowed a preventable disease to spin out of control,” write Lawrence Gostin and Eric Friedman. Gostin, a Georgetown Law professor, is Director of the World Health Organization Collaborating Center on Public Health Law & Human Rights. Friedman is Project Leader for the Joint Action and Learning Initiative on National and Global Responsibilities for Health.
An open letter to European governments on behalf of 44 signatories declares the Ebola epidemic “has now spiraled utterly out of control.”
“Today, the virus is a threat not only to the countries where the outbreak has overwhelmed the capacity of national health systems, but also to the entire world,” say the letter also published in Lancet.
CDC Is Optimistic
Dr. Frieden says the CDC and Texas state officials “remain confident that wider spread in the community can be prevented with proper public health measures, including ongoing contact tracing, health monitoring among those known to have been in contact with the index patient, and immediate isolations if symptoms develop.”
But trust in the CDC is not strong in all corners. One physician who has worked in Emergency Rooms for more than twenty years commented on the CDC’s repeated proclamations that it’s not easy to catch Ebola. “Hard to transmit,” says the doctor. “Yet a health care worker following universal precautions caught it from a patient.”
After the announcement of the first infected nurse, Dr. Frieden spoke at yet another news conference saying that special CDC response teams will be dispatched “within hours” to the site of future, confirmed cases. He says he wishes CDC had launched such measures sooner, and that it might have prevented the first nurse from being infected.
The mea culpa surprised several officials who commented that preventing spread of Ebola in the U.S. requires foresight rather than hindsight.