WASHINGTON, DC, June 13, 2005 (ENS):
A U.S. beef cow has tested positive for mad cow disease,
and a sample of the animal's brain has been sent to
an independent laboratory in the United Kingdom for
confirmatory testing, Agriculture Secretary Mike Johanns
said late Friday night. The suspect animal was a downer
cow, one unable to walk, so it never entered the food
chain, Johanns said.
Only one case of mad cow disease has been confirmed
in the United States, in a dairy cow in Washington State
in December 2003. Since then, preliminary tests indicated
the possibility of the disease in three cows, but further
testing had ruled out any infection.
USDA officials decided last week to perform additional
tests, and test results on one of those three cows turned
Johanns said the Agriculture Department Office of Inspector
General had recommended the additional testing, but
the secretary did not say why. The Inspector General's
Office is an independent arm of the department that
performs audits and investigations.
Formally called bovine spongiform encephalopathy, or
BSE, mad cow disease happens when proteins in the body
bend into misfolded shapes called prions. Prions deposit
plaque that kills brain cells, leaving spongy holes
in the brain. The disease is always fatal.
People can get a form of the disease, called variant
Creutzfeldt-Jakob disease, by eating contaminated meat.
The disease has killed about 150 people worldwide, mostly
in the United Kingdom, where there was an outbreak in
the 1980s and '90s.
Since the first case of mad cow disease was found in
December 2003 in Washington state, about 375,000 U.S.
animals have been tested for the disease, usually those
that appear sick.
Tissue from the three suspect animals has been tested
three times, using three different procedures.
Results were positive for one cow on one of the three
tests. The other tests were either inconclusive or negative
for all three cows.
Initial screening called rapid tests indicated the
potential for mad cow disease in the three cows.
These three animals tested inconclusive in initial
screening, called rapid tests. Rapid tests check for
mad cow disease by removing normal proteins, then adding
chemicals that bind to the abnormal BSE prions so that
researchers can see them.
Tissue from the three cows was was later subjected
to immunohistochemistry, or IHC, testing. The IHC is
an internationally recognized confirmatory test for
BSE that stains brain tissue samples to highlight the
All three inconclusive samples tested negative using
the IHC test, said Dr. John Clifford, chief veterinary
officer with the USDA's Animal and Plant Health Inspection
Last week, the USDA Inspector General's Office recommended
that the three tissue samples be subjected to a second
internationally recognized confirmatory test, the Western
Blot, or immunoblot. This test destroys normal protein
to leave only the abnormal prions.
Both tests both tests are accepted by the OIE, the
World Animal Health Organization.
Clifford said USDA officials received the results of
the Western Blot test last Friday night, and, "of
the three samples two were negative, but the third came
back reactive on that test."
"Because of the conflicting results on the IHC
and Western Blot test," said Clifford, "a
sample from this animal will be sent to the OIE recognized
reference laboratory for BSE in Weybridge, England.
USDA will also be conducting further testing which will
take several days to complete."
Clifford hastened to reassure the public that no meat
from the suspect animal entered the food supply. "It
was a nonambulatory downer animal and as such was banned
from the food supply," he said. "It was taken
to a facility that handles only animals unsuitable for
human consumption, and the carcass was incinerated."
Both Johanns and Clifford said the U.S. meat supply
is safe because no "specified risk materials"
are allowed into the human food supply. These are nervous
system tissues such as brain and spinal cord tissues,
the eyes, and the small intestine. These parts are considered
risky because in animals with BSE disease, the brain
and spinal cord contain the greatest concentration of
the BSE agent.
The agriculture officials did not release the location
where the suspect animal was raised. They would only
say that there was no information that it was an imported
animal. Clifford said the animal was an aged animal.
"It was getting up in age and was a beef breed."
The age of BSE suspect animals is important because
it takes at least 20 months for the disease to develop.
Secretary Johanns emphasized that he did not want this
discovery of a suspect animal to derail beef trade talks
now underway with other countries.
"I feel very strongly that this information should
not impact our discussions with Japan, Korea or Canada,"
"As the doctor pointed out, this is an aged animal,"
said Johanns. "Our discussions with Japan have
related to 20 month animals as you know. Our discussions
with Korea have related to 30 month animals, and the
rule relative to Canada, or the Minimal Risk Rule in
general, I should say relates to animals under 30 months
and meat product under 30 months."
The United States closed its border to Canadian beef
after May 2003 when a BSE infected cow was found in
Japan, which has had 20 cases of mad cow disease despite
a policy that requires testing of all cattle slaughtered
for human consumption, closed its borders to U.S. beef
after December 2003 when the Washington state mad cow
was discovered. That cow was later found to have originated
The disease has thrown the beef industry in both the
U.S. and Canada into turmoil.
An "industry in crisis" was the resounding
theme of testimony given at a USDA roundtable on BSE
held Thursday at the University of Minnesota in St.
Paul. The roundtable discussion of U.S. beef safety
and the economics of BSE on the industry brought together
more than 200 attendees including USDA experts, producers,
packers, other industry groups and academics.
Secretary Johanns opened the discussion by explaining
the critical importance of the cattle and beef embargo
to the U.S. beef industry and its potential impact.
Each day the border remains closed to Canada there is
an increased possibility that these changes will become
permanent, he said.
Johanns noted that one of the most recent victims of
the embargo, Packerland Packing, in Gering, Nebraska,
announced last week that they were closing their doors
for good and laying off more than 200 workers.
Johanns said it is difficult to ban trade with Canada
while trying to open markets abroad. "It is difficult
to ask Japan to treat us one way when we are treating
another major trading partner another way,” he
APHIS Administrator Ron DeHaven, who was the agency's
chief veterinary officer when the first U.S. case of
BSE was found, told the roundtable that Canadian preventive
measures are virtually identical to those in the United
“The risk of BSE transmission in the U.S. and
Canada is extremely low,” DeHaven said, noting
that "USDA is fully confident that American and
Canadian cattle are equally protected from BSE."
But others are not so sure.
News stories May 31 on Dow Jones Newswires and June
1 in the "Wall Street Journal" revealed an
internal USDA document called a "decision memorandum"
from October 2003, in which top USDA officials reversed
a May 2003 ban on imports of certain Canadian processed
and rendered beef products, including ground beef, that
could have potentially contained the BSE infective agent.
The memo stated that the expansion of imports requested
by the National Food Processors Association and others,
“increases the possibility that higher risk product
... may be imported into the United States,” and
warned that the decision would be a “significant
change in policy without opportunity for public comment.”
Bill Bullard, CEO of R-CALF United Stockgrowers of
America, said the memo shows that USDA has not adhered
to sound scientific principles, but rather has been
basing critical decisions on inappropriate considerations,
including pressure from the meat processing and packing
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