he
recent appearance of a single case
of mad cow disease in Canada brought back frightening memories of
the outbreak of this disease (a.k.a. bovine spongiform encephalopathy,
or BSE) that rocked Great Britain and Europe and then spread to Israel
and Japan in the l990s. Millions of cattle were killed and burned to control
the outbreak.
Mad
cow has no cure and is always fatal. It eats holes in the brains of its
victims, and what makes it even more serious is that it can jump the species
barrier to infect humans as a new strain of Creutzfeldt-Jakob Disease
(CJD) — an equally incurable, fatal disease with symptoms like Alzheimers.
CJD normally appears in older adults. What alerted researchers to mad
cow appearing in humans was a rash of CJD appearing in young people, some
in their teens — hence the name New-Variant CJD.
According
to the U.S. Center for Disease Control, from 1995 through June 2002,
124 human cases of NV-CJD were reported in the United Kingdom, 6 in France,
and 1 case each in Ireland, Italy, and the United States. Patients from
Ireland and the U.S. had both lived in the UK for more than 5 years during
the BSE epidemic. The disease can lie dormant for years and there are no
fully reliable tests for it short of biopsies, so no one knows how many
more people will be afflicted.
No cases of mad cow
disease or NV-CJD have
been reported in the U.S. But BSE and CJD have caused waves of panic through
the world, translating to billions of dollars of damage to the beef industry
— not to mention considerable human anxiety and paranoia.
When Oprah Winfrey
did a show about the potential for mad cow in the U.S. in l996, you may
recall, she swore off eating burgers, and was promptly sued by Texas feedlot
organizations who claimed they lost money following her declaration. (Oprah
won the lawsuit and discovered Dr. Phil in the process. He was her juror-selection
consultant.)
The cause of mad cow
disease is still debated in scientific circles but most experts now agree
that an extremely tiny diseased protein particle called a “prion” (pronounced
“pree-on”) is the cause. Prions, which were discovered by Stanley Pruisiner
— winner of a Nobel Prize for his efforts — are infinitesimally
small and do not behave like other infectious vectors like bacteria or viruses.
Understanding prions
— and why they transform from harmless to malevolent entities that
carve up the brains of animals including man — is a quest that could
only be undertaken with the aid of the latest hi-tech science. And making
such complex science interesting and understandable is a challenge. A lot
of college professors fail horribly at the task. The subject matter is extremely
important to modern life, but the manner of presentation is often obtuse,
boring, and mind-boggling confusing — coming off like an in-joke among
a select group.
Philip Yam, Scientific
American writer and editor, has a knack for boiling down complex science
and making it palatable to the general public. Yam demonstrates his skills
in an important new book, The Pathological Protein. At times reading
almost like a Michael Crichton techno-thriller, Yam traces the history of
TSE diseases, leading the reader through the wilderness of cutting-edge
science. His treatment is thorough, entertaining, and honest.
Yam begins with the
study of TSEs from scrapie in sheep, which is found worldwide except in
Australia. He presents considerable evidence to suggest that “renderings”
(scraps from butchering) from scrapie-infected sheep, which were added to
cattle feed, may be the origin of mad cow disease. Then he guides the reader
among cannibals in New Guinea who suffer from the laughing sickness “kuru,”
to research leading to Nobel prizes awarded to Carleton Gajdusek and Stanley
Pruisner, to the Alzheimer’s-like human TSE Crutchfield-Jacob’s disease,
to the mad cow disease outbreak in Europe and the eruption of chronic wasting
disease in deer and elk in the U.S. At each step we learn about the science
and the people and the many questions that remain unanswered.
Yam pulls no punches
in his discussion of Chronic Wasting Disease, a
TSE infecting deer and elk in the United States. He traces it from its
origins at a Colorado wildlife research center and explores various theories
about how it spread to 11 states and several Canadian provinces. Many believe
that CWD originated from contact with sheep infected with scrapie, a TSE.
Others believe the prions could have mutated after exposure to organophosphate
pesticides. Still others feel that a virus is the real villain.
Yam points out that
while there have been no reported cases of CWD infecting people, it is possible.
And he quite accurately suggests that it is very likely that CWD could spread
to all deer and elk herds in the U.S. Too many people are dismissing CWD
as a problem for deer hunters alone. If it is ever found that CWD can jump
the species barrier to livestock or humans, a war on deer and elk will occur.
This book raises the
nagging question of “What is safe to eat?” The World Health Organization
recommends that people not consume animal products from any animal infected
with a TSE disease. But determining in the early stages which animals have
a TSE and which do not is not an easy task.
To answer this question
Yam surveyed many scientists. Would they eat beef in the UK? The answer
is “yes,” with some reservations. Many precautions have been taken. Europe
tests one in four cattle for BSE, and the UK tests all cattle slaughtered
over 30 months, the age when it becomes possible to detect symptoms of BSE.
Most scientists surveyed said that muscle meat, boned from animals, was
just fine. Ground meat — such as sausage and cuts with bones that have
been sawed in half like T-bone steaks (thus exposing the cerebral-spinal
fluid and tissues) — was generally a “no.”
This is definitely
a book for decision-makers to read and underline. The U.S. has never had
a case of BSE and hopefully it never will. But as Yam points out, the U.S.
slaughters over 35 million cattle a year and tests less than 20,000 for
BSE. Japan, in contrast, tests all 1.3 million beef cattle it slaughters
every year. The U.S. imported $1.1 billion of cattle from Canada last year,
and now there is am embargo on importing Canadian cattle into the U.S. due
to one case of BSE.
The U.S. beef industry
is the most economically important segment of the U.S.
farm economy. Beef ranching supports more than one million jobs and
generates $36.5 billion a year just from sales of calves and cattle. The
U.S. produces more beef than any other country. U.S. consumers spent $52
billion on beef in 2002 — the highest amount ever, no doubt in part
due to confidence in meat quality. (Beef sales did dip in the 1990s, quite
probably due to the mad cow situation in the UK.) Protecting the quality
of our beef deserves the highest consideration for public health and the
economy.
The Pathological
Protein is not just a good read; it is a sourcebook of extremely valuable
information about TSEs and a guide to some very suspect areas of farming
and meat producing. It will move many to favor free-range chicken and beef.
—
James Swan is a contributing editor of ESPNOutdoors.com.
He also writes for the Outdoor Channel’s Engel’s
Outdoor Experience, which just won
a Golden Moose for the category “Best Waterfowl Shows 2002.”
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