A Bird-Flu Pandemic Could Start Tomorrow
Bird flu is a disease caused by a specific type of avian (bird)
influenza virus, the so-called H5N1 virus. This virus was first
discovered in birds in China in 1997 and since then has infected
125 people in Vietnam, Cambodia, Thailand, and Indonesia,
killing 64 of them. It is spread by infected migratory birds
(including wild ducks and geese) to domestic poultry (primarily
chickens, ducks, and turkeys), and then to humans.
Since 1997, and especially since the beginning of 2004,
approximately 150 million birds have either died from the
disease or been killed to prevent further spread. Nevertheless,
this very infectious and deadly virus has spread relentlessly to
China, Thailand, Cambodia, Vietnam, South Korea, Japan, Taiwan,
Laos, Russia, Indonesia, Mongolia, Kazakhstan, Malaysia, Turkey,
Romania, England, Croatia, Macedonia, and other countries. This
ongoing geographic extension of the virus is of great concern
around the world. It is feared that it will continue to spread
to all continents, including the Western Hemisphere--and it no
doubt will.
Normally, different types of viruses infect just one, or a
limited number, of species specific to the particular virus
type. The bird-flu virus, however, has infected a large number
of birds and animals, including ducks, chickens, turkeys, tree
sparrows, peregrine falcons, great black-headed gulls,
brown-headed gulls, gray herons, Canada geese, bar-headed geese,
little egrets, pigs, clouded leopards, white tigers, mice,
domestic cats, crows, magpies, peacocks, blue pheasants, rare
eagles, turtledoves, swans, terns, and others. This is another
sign of the virulence or destructiveness of the virus.
Researchers, historians, and infectious-disease experts have
determined that influenza pandemics (global epidemics) occur
approximately once every 30 years. The most deadly pandemic ever
recorded occurred in 1918-19, killing more than 100 million
people across the globe in less than two years. Two other much
less severe pandemics occurred, one in 1957, when approximately
two million people died, and one in 1968, when about one million
people died. Because we have already had three pandemics in less
than 100 years, we are "overdue" for another one.
And so this disease-causing virus continues to infect more and
more species in more and more countries. In laboratory
experiments, it has been shown to be one of the most lethal
influenza viruses ever known. In addition, just recently and
after 10 years of work, researchers determined that the H5N1
bird-flu virus is genetically more similar to the deadly 1918-19
influenza pandemic virus than to the viruses which caused the
much less severe pandemics of 1957-58 and 1968-69.
To summarize the important points so far: The bird-flu virus is
a very deadly strain of avian influenza called H5N1 that has
killed millions of birds; 2) the virus is spreading relentlessly
around the world; 3) the virus has infected many species, which
is uncharacteristic of most viruses; 4) the virus has been shown
to be similar to the most deadly virus ever known, which caused
the 1918-19 pandemic; 5) the virus has been shown to be much
more deadly in laboratory experiments than regular influenza
viruses; and 6) the virus is known to have infected at least 125
humans and killed 64 of them so far, yielding a fatality rate of
approximately 50 percent.
The virus continues to kill humans, but at a slow rate--it has
not yet acquired the capacity to be easily transmissible between
humans; humans become infected primarily from sick birds.
Because humans alive today have no natural immunity to the H5N1
virus, once it becomes easily transmissible between humans a
pandemic or global epidemic will occur. The central question is,
when will it exchange enough genetic material with the usual
seasonal human influenza-viruses to become more like a
human-influenza virus--and thus become easily transmissible
between people?
Many people believe that the virus will continue to spread
around the world until it is present in most or all
countries--before it will "go human" (become easily
transmissible between people). And that may be the case. The
pandemic of 1918-19 is thought to have started in Kansas (of all
places). So it is certainly possible that the coming pandemic
could start somewhere else than in Asia--although most experts
believe it will, in fact, start there. It could start in a
country which has not yet been host to the virus.
However, it is most certainly not necessary for the virus to
march all the way around the world before a pandemic can begin.
The fact that the virus already has spread to more than 15
countries, and to many different bird and animal species,
provides the opportunity for it to commingle with a
human-influenza virus and create the dreaded human contagion.
There is no known reason why this could not happen tomorrow.
While it is true that the probability of the switch increases
with time, the probability of its happening tomorrow is far from
zero.
The flip side to the possibility that the crossover could happen
at any time is the fact that the virus has been around at least
since 1997 and, as a matter of record, has not yet switched to a
deadly human-to-human form. At least a few scientists believe
that the virus can't and won't make the switch to a deadly form,
possibly ever.
And so we are left with these two very different
possibilities--at any time, and as soon as tomorrow, the virus
could mutate into a deadly form, readily transmissible between
people--or it might never transform itself into such a form.
There appears to be much more evidence for the former and,
presumably, that is why the vast majority of scientists and
governments are scrambling to prepare for the worst.
This situation is analogous to living on the Gulf Coast during
the beginning of hurricane season. Residents there have been
through it before, but most of the time the storms are not too
severe and the people can get by without too much hassle.
However, there have been rare severe storms that have been
devastating. Some day another hurricane is coming, and it
appears that it might well be a Category IV or even V by the
time it strikes land. However, that's not certain--no one can
say for sure, and no one knows exactly when it will strike land.
So what should the residents do? What should the residents have
done before hurricane Katrina?
The coming bird-flu pandemic might be mild and it might not come
for years. On the other hand, it might be severe and it might
start tomorrow. The U.S. Government Accountability Office (GAO)
has said, "While the severity of the next pandemic cannot be
predicted, modeling studies suggest that its effect in the
United States could be severe." We should also be mindful that
the pandemic could come at any time, even before the virus
methodically marches around the globe. No matter how advanced
science has become, we still can not predict when the switch
will occur; it is currently unknowable--and that does not mean
it will come later, in a predictable fashion. As Miguel de
Cervantes admonished, "Forewarned, forearmed."
Bradford Frank, M.D., M.P.H., M.B.A. The Frank Group P.O. Box
138 Lakewood, NY 14750 http://www.AvoidBirdFlu.com