Mad cow disease
in humans is called New Variant Creutzfeldt-Jakob Disease, or nvCJD.
It is transferred to people via consumption of contaminated meat,
and is a horrifying, fatal disease that attacks the brain, turning
cells and tissue into a fibrous sponge-like material. The disease
is usually first indicated by signs like depression and sensory
disfunctions, followed by difficulty in walking and loss of memory.
Eventually people with the disease will lose control of all their
faculties and die. In the past, some spongiform brain diseases (which
include nvCJD) have been misdiagnosed as another spongiform disease,
Alzheimer's. Some doctors will not autopsy possible CJD victims
because of its highly infectious nature; surgical tools cannot be
sterilized if they come in contact with the disease.
Dr. Marcus Doherr is a veterinarian epidemiologist at the University
of Bern, Switzerland, who received his Ph.D. from University of
California at Davis. He helped design the Swiss mad cow testing
Doherr says that if the U.S. has as high an incidence of mad cow
as France, for example, the current USDA testing program would not
detect it. "They're not testing enough animals," he says. "The USDA
argues it's a good sample, but it isn't representative of the population
it is trying to extrapolate."
Catch a falling cow?
European countries have for some time been testing a far greater
percentage of their cattle. And unlike the U.S., European countries
are now testing animals which are headed into their food chain.
The U.S. is currently testing a tiny number of "downer cows," cows
which are selected for testing visually by USDA inspectors because
of obvious illness.
Dr. Linda Detwiler, a veterinarian who chairs the BSE Working Group
at the U.S. Department of Agricuture, defends current U.S. testing,
asserting it is adequate to detect mad cow if it is in the U.S.
"We are targeting fallen stock, and we know it's best to target
those cows because in Switzerland, the country with the greatest
scientific experience with spotting the disease, they found all
their BSE cases in fallen stock, and none in testing animals going
into the Swiss food chain."
Actually, that's not entirely correct. Dr. Markus Moser, a molecular
biologist and guest researcher at Oxford University in England,
heads the Swiss company Prionics, which developed a rapid-response
test for BSE, called the Prionics Check Test. Moser says their test
has found cases of mad cow in tests of "healthy" cattle which otherwise
would have entered the food chain.
Moser does agree with Detwiler that BSE has been found in significantly
higher percentages in fallen stock, making it reasonable to focus
initial testing there. However, you can't compare the current U.S.
testing to testing done in Europe, he says. The reason is because
the U.S. has a very different definition of "fallen stock" than
"In Europe," says Moser, "'fallen stock' refers to any cow not regularly
slaughtered, which gets sick or dies, breaks its leg and is destroyed,
or doesn't go into the food chain for any number of reasons. No
such cows can be disposed of in Europe without being tested for
But in the U.S., the term "fallen stock" appears to refer only to
cattle that actually arrive at the slaughterhouse and are so obviously
sick that they are pulled out of the line by a USDA inspector. "Who
would bring a sick animal to an abattoir that they knew was going
to be pulled out?" says Moser.
In fact, U.S. ranchers can dispose of sick cattle in a number of
ways, such as selling them to rendering plants to be turned into
animal food. Unlike Europe, the U.S. does not have the same laws
insuring these fallen cattle are not disposed of without testing
first for BSE.
Dr. Mike O'Connor is another expert who believes U.S. policy could
be improved. O'Connor is a founder and the Technical Director of
Enfer Scientific, in Dublin, Ireland. His company developed the
Enfer rapid-response test for mad cow disease, now used in the UK.
"It's illegal to bury casualty cattle in Ireland," says O'Connor.
"You can't just dispose of them however you want. They must be tested.
That obviously doesn't happen in the U.S."
Dr. Roland Heynkes, a German molecular biologist who has studied
spongiform diseases since 1990, including mad cow, says that German
tracing systems also make it very difficult to bury fallen cattle
without a BSE test. He adds that Germany now tests a much greater
percentage of their cattle now than even Switzerland. "1 out of
every 3 healthy cattle, as well as all fallen cattle over 24 months,
are tested in Germany by law," he says. "In addition, there are
large numbers of voluntary tests of younger cattle, and in contrast
to Switzerland, it's impossible to avoid a BSE test in Germany when
cattle are over 24 months old."
Dr. Dagmar Heim, the head of Switzerland's BSE testing and surveillance
unit, points to the most dramatic illustration showing the difference
between European and U.S. definitions of "downer cows." It's the
number of cows the U.S. counts as "fallen" versus the number Europe
In Switzerland, she says, some 14,000 cows were identified and tested
last year as "high risk/fallen" out of a total of about 800,000
slaughtered. By comparison, the US identified and tested only about
2,000 "fallen cattle" -- out of a total 36 million slaughtered here.
That's a difference between 1.75% of all cows in Switzerland being
identified and tested as fallen cows, and .0056% (five-thousands
of one percent) of all U.S. cows being identified as "downers" and
If the USDA used the same "fallen cattle" definition as Europe and
ended up testing 1.75% of its cattle for mad cow disease - as the
Swiss do - the U.S. would be testing about 630,000 cows per year,
rather than the 2,303 cows tested last year.
Moser says the USDA's claim that it is testing what the Swiss have
identified as a "high risk group" - fallen cattle - is not accurate.
"You're testing a very small sub-population of what Europe looks
at, a tiny fraction of what we consider to be 'fallen cattle.' It's
not the same at all."
Rapid mad cow tests used in Europe -- but not in here
In 1998, the European Union formed a commission to evaluate mad
cow tests. It determined that three tests were reliable and were
suitable for use. The tests recommended by the EU researchers are
Dr. Moser's Prionics Check Test, Dr. O'Connor's Enfer, and a test
produced by a French company. (The French test which was evaluated
by the EU later served as a basis for developing another test which
would work as quickly as Prionics and Enfer, called Platelia BSE,
which is marketed by a U.S. company called Bio-Rad.)
Each of the
three tests currently available in Europe cost about $16 per cow,
designed to provide quick response times, enabling meat packers
to test animals and get results back before slaughtered carcasses
in the plant's "chill room" reach 4 degrees Centigrade, the temperature
at which they can be loaded onto trucks to go to market.
When asked whether the USDA was evaluating or considering using
these newer tests in the U.S., Detwiler said they would look at
them at some point in the future. The reason the USDA isn't looking
more closely at these tests now is because "there's too much demand
for them in Europe," and Prionics, for example, is currently "unable
to send any testing kits to the USDA,"she says. "We can't start
any evaluation if they can't deliver the European tests to us."
Moser of Prionics and O'Connor of Enfer find it surprising Detwiler
would say this. "Our test has been commercially available since
1999," says Moser, "how many do they want?" He says their test is
marketed by Roche Diagnostics in the U.S., which has for sometime
been trying to get the USDA to take interest in it. "It's been available
to the USDA for a long time, if they wanted it."
O'Connor of Ireland is also eager to get the Enfer test to the U.S.
government. "There is no problem getting Enfer tests to the U.S.,"
he says, adding he would be delighted to have Enfer find a home
in the U.S.. "We are trying to get it in there with our marketing
partner, Abbot Diagnostics."
Moser says that a "60 Minutes" producer recently contacted him for
a story, and also told him Detwiler at the USDA had made the same
assertion, that Prionics would be unable for several months to give
the USDA a test to evaluate. "How could the USA not be able to get
our test?" asked Moser.
Asked what the USDA thought of a study published in Nature which
evaluated two of the tests currently commercially available (Prionics
and Enfer), and which affirmed those tests effectiveness, Detwiler
replied she wasn't familiar with the study and needed to read it.
She added that she expected it to take quite some time for the USDA
to evaluate the rapid tests, that it would likely be a long time
before they might be approved.
"Approval is really a gray area," says Moser. "Yes, things often
go through long processes to be formally approved, but the current
method used by the USDA hasn't been approved by anyone."
Approval is also a gray area because the test isn't being given
to live animals, which would normally require many safety tests,
but is being administered to dead brain tissue. The only needed
testing appears to be to determine whether or not the tests work
- which the EU and a number of individual European governments have
already tested and proven perform quite well.
Rapid testing was key to discovering BSE in Germany
BSE was first discovered in Switzerland in 1990, with the Swiss
government instituting numerous consumer protection measures since
then to close off the country from known BSE-sources. In 1998, conventional
testing appeared to indicate that BSE rates had declined dramatically.
Prionics introduced their rapid testing method and began marketing
"Some here in Switzerland were resistant, saying we had BSE under
control, why did we need to do this testing?" said Doherr. But others,
including consumer groups pushed for the new testing to be done
and so Swiss authorities with some reluctance decided to try it.
"It became very apparent there were a lot of BSE cases that were
missed before we used the Prionics test," said Doherr. "We quickly
realized that this rapid testing was a very valuable tool to see
how the epidemic is progressing. There was a dramatic increase of
BSE-infected animals detected." Doherr says nearly four times as
many cases of BSE were found in Switzerland in 1999 when rapid testing
was used, than were found in 1998 using only conventional testing
(the same methods used today in the U.S.).
"This was huge news around the world," said Moser, whose company
produces the test. "Everyone was in shock over this discovery."
Moser says Prionics subsequently convinced Swiss authorities to
do a test on 3000 normal cows, in addition to testing fallen cows.
The results revealed mad cow was also in cows which had no obvious
symptoms, and were headed into the food chain.
"Rapid testing was finding a lot of BSE in Switzerland," says Moser.
Switzerland's beef industry was coming under fire, he says, but
the Swiss argued that their beef was probably no worse than other
EU countries, and the only difference was they had better testing.
They turned out to be right.
Germany had long proclaimed it was BSE-free. They also used the
same testing the U.S. government currently uses. "The Germans didn't
see any BSE," says Moser, "So they said 'We're clean.'"
Heynkes notes that although the German government's position was
that Germany was BSE-free, "several German BSE experts had warned
for years that Germany was unlikely to be BSE-free."
Moser said after Prionics had found a much greater rate of mad cow
than previously detected in Switzerland, his company tried to interest
European governments in their test.
"They were in
a state of denial, saying they didn't have BSE here, that they had
'firewalls' around their countries, they had taken measures to keep
their beef safe, were already testing, and so on." Moser said most
governments weren't immediately interested in fast tests that would
make it possible and affordable to test many cows very quickly.
So Prionics began marketing their rapid test directly to labs in
Germany, and directly to meat producers. "And some of these companies
felt they had a responsibility toward their customers," says Moser.
A few privately were concerned that one day they might have legal
liability if mad cow turned up and infected people.
"If they did some testing now, that would be a reasonable step,"
Moser says. Private labs then performed the Prionics test on a small
number of cattle -- and found BSE in German cows for the first time.
"It snowballed from there, Germany did more rapid testing and found
it had a big problem. It was a huge scandal," says Moser. All consumer
groups in Europe had been pushing for more testing, and now DG24,
the Health and Consumer Protection Directorate-General of the EU,
issued rules for mandatory minimum testing in member countries,
for all fallen cattle and cattle over 30 months of age.
Heynkes said that before the private testing in Germany revealed
BSE, the German government had not wanted to test widely for mad
cow. "But when the people refused to buy untested beef," he says,
"the government had no choice but to test." (Heynkes says if U.S.
consumers really wanted to know whether there was any BSE in their
country, "they would only have to boycott untested beef for a few
weeks" before wide testing would be forced to begin.)
"The importance of this new rapid test is that a lot of other countries
were claiming they had no BSE," says Doherr. "They were not implementing
any consumer measures to protect their public. It was important
that these countries were forced to use this test. It told them,
'You are wrong, you do have BSE, and you need to do something to
protect your consumers.'"
Commercial forces have since taken hold, Moser says, and countries
wanting to sell their beef to other EU countries have had to start
widescale testing to assure their foodchain, or other countries
won't buy from them.
Worthless USDA "firewall" strategy?
Recent studies point to intensive factory farming techniques used
widely in Europe and the U.S. as causing mad cow to develop in herds.
Specifically, the practice of feeding cow protein back to cows is
widely considered to promote and spread mad cow disease. Although
the U.S. enacted laws to stop this practice in 1997, FDA monitoring
in March of 2001 revealed that several hundred U.S. feed factories
are still violating these rules intended to prevent the spread of
Additionally, the U.S. permits the feeding of other animal remains
to cows, which new research suggests may permit continued spread
of mad cow disease. This practice has been outlawed in Europe and
While keeping out meat and feed from countries known to have BSE
is important, some experts say it's very possible if not likely
that the disease can appear spontaneously in a country with farming
techniques used in the U.S. and Europe, even in the absence of any
outside "contamination." In this instance, the current USDA "firewall
strategy" - preventing mad cow from appearing by blocking imports
from BSE countries - would prove of little use.
European experience also shows relying on the judgment of people
in slaughterhouses can be problematic, Moser says, as it requires
a degree of interpretation. "If a vet is not well educated in spotting
signs of BSE, they can easily miss them," he says.
Doherr agrees. "If a cow's production of milk drops significantly,
in Switzerland we test it as a sign of mad cow." In the U.S., however,
that cow is sent to slaughter and into the food chain.
as a subtle chronic disease, and gets more intensive. But it's easy
to miss at early stages if you're not trained," Doherr says. He
says things as simple as a behavioral change -- a cow afraid of
movement, noises or light, or a cow being sensitive to touch - signal
BSE suspicion and trigger testing in Europe, but not in the U.S.
"If a cow kicks when you try to milk it, a U.S. farmer - who is
told 'we don't have BSE here' - will not even think about it," says
Doherr. "He'll just think it's time to replace that cow. People
who think they have no BSE in their country are unlikely to recognize
a case, let alone report it."
Moser also points to potential problems with the conventional Immunohistochemistry,
the testing method used by Germany (which many now realize missed
cases of BSE) and currently used by the U.S. While Moser believes
the test isn't a bad method per se, he says it has potential problems.
"These tests depend on the quality of the tissue," he says. "If
the brain tissue used in the test is not of good quality and is
partly degraded, the test becomes problematic. In the U.S. they're
only analyzing downers, and if the animal is lying down and dead
for a day, the conventional method used in the U.S. doesn't have
a chance to pick up BSE."
He adds that the conventional test itself requires interpretation
of the lab technician in order to be certain of the result. "It
takes a trained person to interpret that test accurately. You can
overlook things," he says.
With his rapid testing technique, Moser says, results are unambiguous.
"It's an objective method. You either have a positive or a negative."
O'Connor says rapid tests are not only faster, but more accurate
than the government test used in Ireland. He says Enfer tests between
three and five thousand cattle per night at their facility in Ireland,
and have results back to the packing plant in the middle of the
night so as not to slow down meat packing operations. BSE-positive
cows are removed before entering the food chain.
"If we get a positive test, as we got a few last night, then we
repeat the test," says O'Connor. "If we get two positive results
on a cow, then we tell the meat processor to hold the carcass, and
we send the sample to the government for their confirmation testing
O'Connor says that in several instances the Enfer tests have come
up positive, but the histology test used by the Irish government
later came back negative, indicating no BSE. O'Connor says Enfer
has insisted the government look again, and another review subsequently
finds that in fact the cow is positive, and the Enfer positive was
"Our test is more sensitive than the government test," he says.
"When there's a disparity, we've had the government double check,
and they come back to us saying, 'Oh yes, you're right, this one
was prion contaminated.'"
The testing used by the Irish government - which can give false
negatives - is also used by the USDA.
Health or political problem?
Moser says the American government is in a defensive position now.
"They're only testing 2,000 cattle a year, and they feel that's
good enough to prove that they don't have BSE in their country,"
says Moser. "So right now BSE isn't being treated like a potential
health problem in the U.S., but a political problem. It's the same
situation European countries were in."
Moser believes the USDA is in a "denial stage." "They don't want
to really look at this. They were taken by surprise at what's happened
in Europe, and they want time to breathe. Rather than be on the
safe side, they don't want to introduce rapid testing right now,"
Moser thinks the U.S. is afraid wider testing might reveal mad cow
is in the U.S., putting the government in a position where they
would have to admit their surveillance has not been sufficient.
"I've seen it before. You mention mad cow disease, and everyone
freezes. The politicians go into hiding. No one wants to comment
on this. It's absolutely amazing."
Moser also can't understand why USDA representatives would tell
reporters his company, Prionics, is unable to get tests to the U.S.
for several months. "It tells me they have no PR concept. They have
no concept on how to deal with the situation. They want to beat
for time. It's a statement that shows they're not prepared," he
Heynkes, the German molecular biologist, goes further. "I think
in Germany she would have to resign after this lie." Heynkes refers
to the January 2001 resignation of the German Agricultural and Health
Ministers over what was widely viewed as their grossly inadequate
reaction to the health threat posed from mad cow disease.
Heynkes agrees with Moser on the reason the US is not rushing to
embrace rapid testing. "These tests have been used in practice several
hundred thousand times now and already identified seemingly healthy
- but BSE infected - cattle," he notes. The problem isn't about
whether or not the rapid tests are accurate, he believes, but that
"the U.S. government simply does not want to test and find BSE."
Moser of Prionics believes the U.S. government is exercising poor
judgment in making extreme statements like "There is no BSE here."
"The problem is, if you get one sick animal, everything changes.
The people will feel they've been lied to by the government. 'We're
not BSE-free after all!'"
Moser says the U.S. should simply say that it's "unlikely" that
we have it. "That way, even if the worst happens, the public is
emotionally prepared. But the way the U.S. is handling it now, as
soon as you have your first case - and I hope you don't, but it's
likely you will - no one will buy beef in the U.S. the next day.
It will destroy the U.S. beef industry because of the way it's being
Moser says this is what happened in Europe. "Then the politicians
will say, 'People are hysterical, people are overreacting.' But
they aren't over-reacting. They're reacting to having been told
something false. They're reacting to having been given a guarantee
in an area where it is impossible to give guarantees. So the U.S.
is taking a dangerous and extreme position."
European questions apply to USA
"Germany isn't a banana republic," says Moser. "It's a major Western
democracy with advanced science and technology." It used the same
science that the U.S. is currently using, he notes, and found no
BSE. "The fact that they then used rapid testing and found big problems,
this suggests that it can very well happen in another modern democracy."
Moser says he believes there is also a "psychological barrier" in
BSE testing. "The veterinarians doing BSE surveillance in slaughterhouses
were reluctant to go out on a limb too often and say, 'This looks
like BSE,'" says Moser.
And in "adamantly BSE-free countries," there's a lot of pressure
on the inspectors who are looking for BSE-suspect animals, he says.
"Imagine what an inspector is triggering if he thinks BSE is spotted.
If it's an error, okay, fine. But if it turns out to be BSE, the
whole slaughterhouse will have to be shut down, the press will probably
get wind of it, and it would be a scandal. Maybe he would lose his
Heynkes points to a German inspector, Dr. Margit Herbst, who claimed
to have seen more than 20 BSE suspected cattle which were not adequately
tested for mad cow. She went public with her concerns, and lost
her job. "But nothing changed," says Heynkes.
Moser says that once a few cases of BSE were spotted with more objective
rapid testing, suddenly European inspectors were finding symptoms
where they hadn't before. "After breaking that psychological barrier,
suddenly everyone was finding BSE symptoms. Surveillance actually
improved dramatically once the ice was broken."
Heynkes agrees. "The first German BSE case was extremely helpful
because otherwise we would still have no useful cattle feed law
now," he says. He notes that the government has had to make BSE
science much more transparent and subject to examination and comment
from non-government powers. "More and more the German government
has to deal with an organized BSE science, making it harder for
consumers to be misled."
Moser doubts there is an organized conspiracy between the meat industry
and government to suppress mad cow findings. Rather, he thinks there's
a human factor involved that "no one likes to see what's not nice
to see" coupled with sorely inadequate testing.
Who's protecting our health?
In most European countries, decisions about BSE programs and testing
are currently being made by politicians. There is much criticism
for the way BSE issues were handled early on, and many Europeans
now believe the interests of agriculture and the meat industry were
much more important in the decision-making process than was the
potential health of the people. In England particularly, recent
reports have been highly critical that BSE was handled predominantly
by agricultural and veterinary officials, when in fact it was a
major potential public health issue, and should have involved the
UK Ministry of Health.
In Germany it was the same way, with only veterinarians dealing
with BSE questions at the beginning. Says Heynkes, "Things only
improve when independent scientific bodies review the risks, and
when government scientists are prepared to ask experts from outside
for input on their drafts." The UK learned this the hard way, from
its BSE crisis, and is what forced them to build up their Food Standards
Agency, says Heynkes.
As in the UK at the early onset of the mad cow crisis, neither the
U.S. Department of Health nor the Center for Disease Control is
setting policy on BSE. This, despite that BSE policy could potentially
have a major impact on public health. Instead, all policy and decision-making
rests with the USDA, whose stated mission is not preventing disease,
but to "Enhance the quality of life for the American people by supporting
production of agriculture."
Says Representative Dennis Kucinich (D-Ohio), who wants the U.S.
Congress to look into the issue of BSE testing, "Public health and
safety requires demanding and immediately employing the latest and
most accurate testing methods available."
For the moment, improving mad cow testing techniques is not the
USDA's focus. According to Detwiler, who plans and supervises the
USDA's BSE program, the thrust is on improving visual surveillance.
This means educating people, says Detwiler. "Just like George Bush
is flying around the country trying to rally people to his tax cut
plan," she says, "I'm flying around the country to rally people
to do better surveillance. Tomorrow I fly to Nebraska for an event."
But according to European experts, without instituting a working
cattle identification and tracing system, the USDA's plans to tout
increased surveillance will probably not not be enough. Only
by making and enforcing laws which track cattle will the U.S. be
able to prevent farmers from simply burying BSE-suspected cattle
without being tested, says Heynkes.
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