May 23, 2006, 1:29AM
As the dire predictions of a pandemic mount, skeptics warn of the dangers of overreaction
Some don't buy bird flu threat
By TODD ACKERMAN
Copyright 2006 Houston Chronicle
http://www.chron.com/disp/story.mpl/metropolitan/3881291.html
For months, the warnings have been relentless: Bird flu could jump species and kill tens of millions of people, a pandemic to rival the 1918 Spanish flu. Economies would collapse and governments risk catastrophe if they don't put together elaborate contingency plans.
Not everyone is convinced, however. A small group of skeptics says the warnings are just a lot of hype, scare talk that does more harm than good to the public health. Such doomsday predictions go well beyond good science and siphon money and attention from more important threats, they say.
"It's a great story, a disease that can wipe out mankind as we know it," says Dr. Gary Butcher, a University of Florida veterinarian specializing in avian diseases. "Fortunately, the facts are contrary to what's being reported. This disease is going to fizzle out, be forgotten in the near future and be replaced by another 'potential worldwide threat.' "
That view may have received a boost last week when the United Nations' chief pandemic flu coordinator confirmed that the flu virus known as H5N1 largely has been contained in the Asian countries where it first hit.
Public health officials were quick to warn it would be premature to declare victory. Dismissive of those who play down the threat, they argue it would be irresponsible not to plan for a worst-case scenario.
H5N1, they note, shares many genetic features with the Spanish flu, according to a research team that reconstructed the horrific 1918 virus — except it's even more lethal. The new virus has killed nearly 57 percent of its 217 confirmed human carriers. The 1918 pandemic paralyzed society, but the resulting 20 million to 50 million deaths represented just 2 percent of those infected.
In addition to common flu symptoms like fever and cough, those infected with the H5N1 virus can develop viral pneumonia or other life-threatening complications within days. The virus, to date, is believed only to have been transmitted to humans through direct contact with diseased birds.
Virus transmission The most recent reported deaths attributed to H5N1 were those of six Indonesians, five of them in an extended family. The deaths, reported last week, initially were investigated as a "cluster" that health experts feared could mean the virus was mutating into a form more easily passed between humans. World Health Organization investigators have all but ruled out human-to-human transmission, saying the virus likely was caught from infected animals.
It's the idea of easy transmission between humans that brings out the apocalyptic visions. One researcher went so far as to suggest half the world's population could die in such a pandemic. U.S. Secretary of Health & Human Services Michael Leavitt advised Americans to stockpile cans of tuna fish and powdered milk in case of an outbreak. And officials have called for more than 100 million doses of a still-to-be-developed vaccine for the virus to be made available to Americans.
Contrarians such as Butcher say it's all a bit much, considering that some experts doubt the current lethal form of the virus will ever jump to humans . They also note that the three pandemics of the last century claimed successively fewer lives. The last, in 1968, killed 34,000 people, fewer than the number who succumb each year to seasonal flu.
Bird flu, they argue, is just the latest in a line of overhyped scares that include anthrax, West Nile virus, smallpox and SARS, which taken together claim a mere fraction of the lives lost every year to, say, pneumonia.
The skeptics warn of the dangers of overreaction, citing 1976's swine flu debacle, when more than 40 million people received a vaccine against a new pig virus that, ultimately, never took hold. The virus killed one person, a military recruit whose speedy death ignited the crash program. But as many as 1,000 people who were inoculated developed a paralyzing nerve condition; 32 died. The public relations nightmare and lawsuits against the government helped drive many drug companies away from making flu vaccines at all.
One reason some remain unconvinced of the new virus's potential transmissibility is because it has infected so few people to date. Since
1998, hundreds of millions of chickens in Asia have been infected with the virus. Millions of people lived with the diseased birds, but, as of last Friday, 217 had become infected. Of those, 123 died.
The high fatality rate also is suspect, according to the naysayers. No one knows how many people in close contact with domesticated birds may have picked up the virus, but never got sick or only showed mild symptoms, and, thus, never reported the disease.
The current flu virus, H5N1, is what is infecting birds. That virus, however, infects humans by lodging deep in the lungs, and, thus, isn't likely to be spread by coughing or sneezing.
The fear among scientists is that the avian flu strain will mix with a human flu, producing a new, easily transmissible virus against which people have no immunities.
"It would be devastating if it gained the ability to spread easily from person to person," said Dr. Wendy Keitel, a molecular virologist at Baylor College of Medicine. "Its fatality rate in humans is unprecedented, as is the extent and severity of the outbreaks in poultry."
Differing views But Paul Ewald, a professor of evolutionary biology at the University of Louisville, said such pathogens would lose their virulence, a law of natural selection ignored by those who fear the worst-case scenarios.
"Everything we know about evolution says pathogens have to become more mild to keep their host mobile," Ewald said. "If they're so virulent the host can't pass them on, they don't survive."
The exception, he said, occurs in "disease factories" — environments where people immobilized by illness can easily transmit a virulent pathogen to new hosts — which is what happened on World War I's Western Front with the Spanish flu. Hospitals, trains and trenches packed with deathly ill and healthy soldiers facilitated the disease's lethal spread.
Public health officials respond that researchers still don't know exactly what made the Spanish flu so deadly, particularly to the young and healthy. They say they can't afford to do little and hope time proves Ewald's theory correct.
Are grants driving hype? Some critics see a different "agenda" behind the public concern about bird flu — funding. Butcher says President Bush's $7.1 billion flu pandemic plan means a bonanza of grant money for researchers and the justification of the budgets and existence of agencies such as the U.S. Department of Agriculture and the World Health Organization.
The bait is not taken by many officials most concerned about the bird flu threat. One such, Dr. C.J. Peters, director of biodefense at the University of Texas Medical Branch at Galveston, calls the more vocal skeptics "well-intentioned folks reacting to media hype."
Some mostly just wish the money wasn't being directed so single-mindedly to the new virus. With nearly 150 different strains of flu viruses with the potential to cause a pandemic, New York University School of Medicine internist Dr. Marc Siegel said he'd like to see more effort aimed at general pandemic preparation, such as developing better methods for making vaccines, and less given to panic-inducing rhetoric.
"I'm concerned that the public discussion about bird flu, the new bug du jour, is so weighted with end-of-the-world terms that it's causing a kind of hysteria," said Siegel, author of Bird Flu: Everything You Need to Know About the Next Pandemic. "The greatest problem isn't influenza — it's fear of influenza."
todd.ackerman@chron.com
Informant: Teresa Binstock
http://freepage.twoday.net/search?q=swine+flu
