[lit-ideas] Re: Protect the patents!
- From: Robert Paul <robert.paul@xxxxxxxx>
- To: lit-ideas@xxxxxxxxxxxxx
- Date: Fri, 04 Nov 2005 16:24:59 -0800
This article has been the subjedct of much Internet discussion. I'll
post sites where it's been discussed, in a bit.
http://www.latimes.com/news/printedition/opinion/la-op-bird23oct23,0,3979726,print.story
Sure, it kills birds, but it won't kill you
By Wendy Orent
Wendy Orent is the author of "Plague: The Mysterious Past and Terrifying
Future of the World's Most Dangerous Disease."
October 23, 2005
IT MUST SEEM like the sky is falling — that it's about to rain chaos and
death as the dreaded H5N1 avian flu appears to close in.
Last spring, bird flu broke out in Cambodia, Thailand and Vietnam. It
spread to western China, Siberia, Kazakhstan and Mongolia in the summer.
How did it travel half a continent?
Though maps of the outbreaks show the flu following roads, railway lines
and national borders, many flu experts insist that migratory birds
spread the virus across Asia. Julie Gerberding, director of the Centers
for Disease Control and Prevention, warned that some of the birds might
fly to Alaska, then down into the United States, bringing the bird flu
with them. That hasn't happened, but the virus appears to be in Europe.
Last week, ducks and chickens were found dead in Romania, Turkey and Greece.
News reports make the threat even more ominous. In resurrecting the 1918
pandemic virus, the deadliest flu strain of all time, researchers
recently learned that this strain was far deadlier than any other human
virus — it killed mice, while normal human flu won't even ruffle a
mouse's fur. They also found out that all of its genes came, directly or
indirectly, from birds. Unlike the pandemics of 1957 and 1968, the 1918
version didn't arise from a combination of bird and mammal genes.
Instead, the bird genes evolved into a human virus that killed as many
as 50 million people.
This means, say breathless news reports, that what happened in 1918
could happen again, this time with H5N1.
But Peter Palese doesn't think so. He is lab director at Mount Sinai
Hospital in New York, where the technique that re-created the 1918 genes
— known as reverse genetic engineering — was developed. He and associate
Adolfo Garcia-Sastre contend that what the resurrected virus really
shows is how supremely adapted it is — how well its parts fit together,
how perfectly it works. The sublime malignance of the 1918 virus doesn't
lie in one part but rather in how the genes function together. Evolution
shaped this virus to be a sleek, effective killing machine.
We don't know what bird the genes came from originally. It wasn't a
domestic duck, chicken or goose, because their flu strains are quite
different. According to Jeffery Taubenberger, the senior researcher at
the Armed Forces Institute of Pathology, the 1918 flu originated in an
unknown bird reservoir, one equally distant from American and Eurasian
birds. "To me, it's from an unknown host, evolutionarily isolated from
other birds," Taubenberger said last year.
But all wild-bird viruses are mild. They have to be: Sick birds don't
fly far, and dead birds don't fly at all. Although H5N1, which evolved
among domestic poultry in the crowded conditions of Asian farms and
markets, has demonstrated the ability to kill wild birds in the
hundreds, it cannot continue to be so deadly and still spread among them.
In nature, flu viruses in birds are intestinal diseases. Through feces,
flu particles are deposited in water, where another duck or goose picks
them up, gets infected and sheds the virus in turn. Wild-bird flu
depends on mobile hosts to spread. If flu strains kill their hosts in
the wild, the lethal versions will vanish. This is why evolution pushes
wild-bird strains toward mildness.
To think that the 1918 flu started out as a harmless intestinal bird
virus that jumped directly from its wild host into human beings and
immediately turned into an explosive respiratory killer is to believe
that hippos fly. Evolution doesn't work that way. The flu's genes came
from birds, but it's what they did when they got into humans that matters.
Somehow, somewhere, the mysterious gene collection that made up the 1918
killer influenza acquired its adaptive and lethal abilities in people.
Most influenza viruses are respiratory and require mobile human hosts,
who become viral distribution machines. You might be miserable with the
flu, but you're still able to walk around, shake hands, sneeze on your
keyboard and talk to colleagues with a halo of virus around you.
But the 1918 pandemic strain was different. According to evolutionary
biologist Paul W. Ewald of the University of Louisville, its lethality
evolved in the trenches, the trucks, the trains and the hospitals of
World War I. Infected soldiers were packed shoulder to shoulder with the
healthy, and even the deadliest virus can jump from one host to another.
The Western Front was a disease factory, and it manufactured the 1918
flu. The packed chicken farms of Asia are a close parallel. H5N1 evolved
the same way as the 1918 flu did in the trenches.
We don't know what will happen to H5N1 as it moves through Europe. It is
certain, though, that the longer it lives in wild birds, the more likely
it will become mild, at least for its wild-bird hosts. This is what
happened to the 1918 flu after soldiers abandoned the Western Front. In
just over a year, the virus lost its virulence and wandered the planet
as an ordinary flu.
The lesson here is that the flu virus, like all of life, is subject to
evolution. Lethal diseases don't fall out of the sky. They evolve in the
context of a host and that host's conditions of life. There is no sign,
so far, that H5N1 is turning into a human disease — effectively
spreading from person to person. Even if it does, it needs a Western
Front to become more than ordinary.
If you want other stories on this topic, search the Archives at
latimes.com/archives.
Copyright 2005 Los Angeles Times
--------------------------------
Robert Paul
Reed College
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