In 1918, the Spanish flu epidemic left 675,000 dead in
the United States over the course of eight or nine months,
with more than 40 million perishing worldwide.
Those figures could be similar if the avian bird flu that
struck humans in China on a small scale in 2003 were to
become a worldwide pandemic, said an Eastern Michigan University
biology professor.
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VandenBosch |
"The Centers for Disease Control (CDC) estimates that
a medium-size pandemic would be a problem in the United
States," said Jim VandenBosch, who presented "Avian Flu:
A Microbiologist's View" to a group of approximately 40
faculty, staff and students at the Village Commons' Multipurpose
Room Nov. 30. The discussion was part of the Honors College's
Star Lecture Series.
If there is no vaccine or drugs available, VandenBosch
said the CDC estimates there would be 89,000-207,000 deaths
and 314,000-734,000 hospitalizations if a medium-sized
pandemic broke out in the U.S.
"Fifteen to 35 percent of the U.S. population would be
affected. The economic impact would be between $71.3 billion
and $166.5 billion. Our preparedness is our (health) insurance," he
said.
That's because, under a plan unveiled Nov. 2 by President
George W. Bush, it would take $1.2 billion just
to acquire 40 million doses of bird flu vaccine, a supply
for roughly 20 million persons. And then, it is estimated,
it wouldn't be until 2009 that that much vaccine would
be available for use.
Bush's plan also includes the federal government spending
another $1 billion to stockpile antiviral drugs like Tamiflu
and Relenza to protect first responders, with individual
states and local governments purchasing $583 million worth
of antiviral drugs.
However, VandenBosch cautions that
Tamiflu likely won't be effective against avian bird
flu. That's because, of persons treated with Tamiflu while
infected with bird flu, 15-18 percent of those people treated
had a virus that was resistant to the drug, according to
a Sept. 29, 2005 article in the New England Journal of
Medicine, VandenBosch said.
What is bird flu?
Avian influenza, or “bird flu,” is
a contagious disease of animals caused by viruses
that normally infect only birds and, less commonly,
pigs. Avian influenza viruses are highly species-specific
but have, on rare occasions, crossed the species
barrier to infect humans.
From mid-December 2003 through early February
2004, poultry outbreaks caused by the H5N1 virus
were reported in eight Asian nations (listed in
order of reporting): the Republic of Korea, Viet
Nam, Japan, Thailand, Cambodia, Lao People’s
Democratic Republic, Indonesia, and China. Most
of these countries had never before experienced
an outbreak of highly pathogenic avian influenza
in their histories.
Information from World Health Organization Web
site
|
"We may be totally screwed or we may dodge the bullet," VandenBosch
said.
Worldwide, between 2 million and 7.4 million would die
if there were a pandemic, according to the World Health
Organization. To date, there have been 132 known cases
of avian bird flu in humans since 1997. Of that total,
68 have died.
VandenBosch said he expects avian flu will eventually
be spread through bird species' typical migration patterns
and could arrive sooner by exotic birds imported into the
U.S.
The normal strain of flu typically kills the very young
and the very old. But the avian flu, referred to as H5N1
for its genetic makeup, hits people in the prime of their
lives and can kill in as little as nine to 10 days, he
said.
"Children and young adults are at the greatest risk. The
mean age is around 16 years old," VandenBosch said. "There's
something unusual happening with this disease that we don't
understand."
Typical influenza viruses mutate (known as antigenic drift)
at high rates because their genetic material is made up
of RNA. The medical community compensates for that antigenic
drift by changing the flu vaccine strain each year, using
three probable strains seen in the preceding years.
However, the avian flu contains genetic material that
has not been seen in the general population in many years,
thereby leaving little or no immunity for the general population.
This is known as antigenic shift, he said.
"Because we don't have that immunity, it will spread quickly
and creates bad disease," VandenBosch said.
Since 1997, the bird flu has become more virulent, broadened
its host range and is changing its disease patterns in
humans and waterfowl, its natural reservoir, he said.
However, he said if health officials knew what mutations
were necessary for the bird flu to spread from person to
person, they could model the probability of the virus spreading.
 |
FOWL PREDICTIONS: Duane Newton, director
of
clinical microbiology and virology laboratories
at the
University of Michigan's Department of Pathology,
makes a point while displaying a photo of birds
in
Asia that were killed because they carried the
avian
flu. A panel of public health experts discussed
the
potential threat of bird flu and what the U.S.
is doing
to prepare for a potential pandemic. Photo
by Craig Watson |
"It might be that we are only one mutation away or it
might be that there is something inherent in H5 that prohibits
it from being spread person to person," VandenBosch said. "Just
as important, the shape of H5 that allows contagion might
be sufficiently different from our current strains that
the vaccine won't work."
At the same time VandenBosch spoke, a panel of public
health experts discussed many of the same important issues
surrounding the potential threat of an avian flu influenza
epidemic and what the United States is doing to prepare
for such an event. A crowd of more than 100
attended the seminar in the McKenny Union Ballroom.
Surveillance and monitoring for avian flu in the U.S.
will be key to stopping an outbreak, said Eden Wells, a
medical epidemiologist with the State of Michigan's Michigan
Department of Community Health (MDCH).
"Surveillance will be the front line of defense," Wells
said. "MDCH gets reports from schools, doctors, hospitals
and local health departments."
Like VandenBosch, Wells said the assumption is that the
U.S. won't have enough bird flu vaccine available once
a pandemic is identified. Even if enough vaccine was available,
it would take approximately one year to vaccinate the entire
U.S. population, she said.
"Flu is now arriving at Gate 4 (at the airport)," EMU
graduate Laura Bauman, an epidemiologist with Washtenaw
Public Health, said for dramatic effect. "We have to be
ready. Our international community puts us at a risk."
While a bird flu pandemic is a future possibility, there
is much the population can do today to combat the bird
flu, including: get annual vaccinations, wash hands frequently,
cover your cough and stay home from work or school when
sick, Wells said.
