October 2001, 34-year-old Washington State native
Peter Putnam started losing his mind. One month he was
delivering a keynote business address, the next he
couldn't form a complete sentence. Once athletic, soon
he couldn't walk. Then he couldn't eat. After a brain
biopsy showed it was Creutzfeldt-Jakob disease, his
doctor could no longer offer any hope. "Just take him
home and love him," the doctor counseled his family.
Peter's tragic death, October 2002, may have been caused
by Mad Cow disease.
Seven years earlier and 5000 miles away, Stephen
Churchill was the first in England to die. His first
symptoms of depression and dizziness gave way to a
living nightmare of terrifying hallucinations; he was
dead in 12 months at age 19. Next was Peter Hall, 20,
who showed the first signs of depression around
Christmas, 1994. By the next Christmas, he couldn't
walk, talk, or do anything for himself. Then it was
Anna's turn, then Michelle's. Michelle Bowen, age 29,
died in a coma three weeks after giving birth to her son
via emergency cesarean section. Then it was Alison's
turn. These were the first five named victims of
Britain's Mad Cow epidemic. They died from what the
British Secretary of Health called the worst form of
death imaginable, Creutzfeldt-Jakob disease, a
relentlessly progressive and invariably fatal human
dementia. The announcement of their deaths, released on
March 20, 1996 (ironically, Meatout Day), reversed the
British government's decade-old stance that British beef
was safe to eat.
It is now considered an "incontestable fact" that
these human deaths in Britain were caused by Bovine
Spongiform Encephalopathy (BSE), or Mad Cow disease.
Bovine means "cow or cattle," spongiform means
"sponge-like," and encephalopathy means "brain disease."
Mad Cow disease is caused by unconventional pathogens
called prions--literally infectious proteins--which,
because of their unique structure, are practically
invulnerable, surviving even incineration at
temperatures hot enough to melt lead. The leading theory
as to how cows got Mad Cow disease in the first place is
by eating diseased sheep infected with a sheep
spongiform encephalopathy called scrapie.
In humans, prions can cause Creutzfeldt-Jakob disease
(CJD), a human spongiform encephalopathy whose clinical
picture can involve weekly deterioration into blindness
and epilepsy as one's brain becomes riddled with tiny
holes.
We've known about Creutzfeldt-Jakob disease for
decades, since well before the first mad cow was
discovered in 1985. Some cases of CJD seemed to run in
families; other cases seemed to just arise spontaneously
in about one in a million people every year, and were
hence dubbed "sporadic." The new form of CJD caused by
eating beef from cows infected with Mad Cow disease,
though, seemed to differ from the classic sporadic CJD.
The CJD caused by infected meat has tended to strike
younger people, has produced more psychotic symptoms,
and has often dragged on for a year or more. The most
defining characteristic, though, was found when their
brains were sampled. The brain pathology was vividly
reminiscent of Kuru, a disease once found in a New
Guinea tribe of cannibals who ate the brains of their
dead. Scientists called this new form of the disease
"variant" CJD.
Other than Charlene, a 24 year old woman now so
tragically dying in Florida, who was probably infected
in Britain, there have been no reported cases of variant
CJD in the U.S. Hundreds of confirmed cases of the
sporadic form of Creutzfeldt-Jakob disease, however,
arise in the United States every year, but the beef
industry is quick to point out these are cases of
sporadic CJD, not the new variant known to be caused by
Mad Cow disease. Of course, no one knows what causes
sporadic CJD. New research, discussed below, suggests
that not hundreds but thousands of Americans die of
sporadic CJD every year, and that some of these CJD
deaths may be caused by eating infected meat after all.
Although the fact that Mad Cow disease causes variant
CJD had already been strongly established, researchers
at the University College of London nevertheless created
transgenic mice complete with "humanized" brains
genetically engineered with human genes to try to prove
the link once and for all. When the researchers injected
one strain of the "humanized" mice with infected cow
brains, they came down with the same brain damage seen
in human variant CJD, as expected. But when they tried
this in a different strain of transgenic "humanized"
mice, those mice got sick too, but most got sick from
what looked exactly like sporadic CJD! The Mad Cow
prions caused a disease that had a molecular signature
indistinguishable from sporadic CJD. To the extent that
animal experiments can simulate human results, their
shocking conclusion was that eating infected meat might
be responsible for some cases of sporadic CJD in
addition to the expected variant CJD. The researchers
concluded that "it is therefore possible that some
patients with [what looks like]... sporadic CJD may have
a disease arising from BSE exposure."Laura Manuelidis,
section chief of surgery in the neuropathology
department at Yale University comments, "Now people are
beginning to realize that because something looks like
sporadic CJD they can't necessarily conclude that it's
not linked to [Mad Cow disease]..."
This is not the first time meat was linked to
sporadic CJD. In 2001, a team of French researchers
found, to their complete surprise, a strain of scrapie--"mad
sheep" disease--that caused the same brain damage in
mice as sporadic CJD. "This means we cannot rule out
that at least some sporadic CJD may be caused by some
strains of scrapie," says team member Jean-Philippe
Deslys of the French Atomic Energy Commission's medical
research laboratory.
Population studies had failed to show a link between
CJD and lamb chops, but this French research provided an
explanation why. There seem to be six types of sporadic
CJD and there are more than 20 strains of scrapie. If
only some sheep strains affect only some people, studies
of entire populations may not clearly show the
relationship. Monkeys fed infected sheep brains
certainly come down with the disease. Hundreds of "mad
sheep" were found in the U.S. in 2003. Scrapie remains
such a problem in the United States that the USDA has
issued a scrapie "declaration of emergency. "Maybe some
cases of sporadic CJD in the U.S. are caused by sheep
meat as well.
Pork is also a potential source of infection. Cattle
remains are still boiled down and legally fed to pigs
(as well as chickens) in this country. The FDA allows
this exemption because no "naturally occurring" porcine
(pig) spongiform encephalopathy has ever been found. But
American farmers typically kill pigs at just five months
of age, long before the disease is expected to show
symptoms. And, because pigs are packed so tightly
together, it would be difficult to spot neurological
conditions like spongiform encephalopathies, whose most
obvious symptoms are movement and gait disturbances. We
do know, however, that pigs are susceptible to the
disease--laboratory experiments show that pigs can
indeed be infected by Mad Cow brains--and hundreds of
thousands of downer pigs, too sick or crippled by injury
to even walk, arrive at U.S. slaughterhouses every year.
A number of epidemiological studies have suggested a
link between pork consumption and sporadic CJD.
Analyzing peoples' diet histories, the development of
CJD was associated with eating roast pork, ham, hot
dogs, pork chops, smoked pork, and scrapple (a kind of
pork pudding made from various hog carcass scraps). The
researchers concluded, "The present study indicated that
consumption of pork as well as its processed products
(e.g., ham, scrapple) may be considered as risk factors
in the development of Creutzfeldt-Jakob disease."
Compared to people that didn't eat ham, for example,
those who included ham in their diet seemed ten times
more likely to develop CJD. In fact, the USDA may have
actually recorded an outbreak of "mad pig" disease in
New York 25 years ago, but still refuses to reopen the
investigation despite petitions from the Consumer's
Union (the publishers of Consumer Reports magazine).
Sporadic CJD has also been associated with weekly
beef consumption, as well as the consumption of roast
lamb, veal, venison, brains in general, and, in North
America, seafood. The development of CJD has also,
surprisingly, been significantly linked to exposure to
animal products in fertilizer, sport fishing and deer
hunting in the U.S., and frequent exposure to leather
products.
We do not know at this time whether chicken meat
poses a risk. There was a preliminary report of
ostriches allegedly fed risky feed in German zoos who
seemed to come down with a spongiform encephalopathy.
Even if chickens and turkeys themselves are not
susceptible, though, they may become so-called "silent
carriers" of Mad Cow prions and pass them on to human
consumers. Dateline NBC quoted D. Carleton Gajdusek, the
first to be awarded a Nobel Prize in Medicine for his
work on prion diseases, as saying, "it's got to be in
the pigs as well as the cattle. It's got to be passing
through the chickens." Dr. Paul Brown, medical director
for the US Public Health Service, believes that pigs and
poultry could indeed be harboring Mad Cow disease and
passing it on to humans, adding that pigs are especially
sensitive to the disease. "It's speculation," he says,
"but I am perfectly serious."
The recent exclusion of most cow brains, eyes, spinal
cords, and intestines from the human food supply may
make beef safer, but where are those tissues going?
These potentially infectious tissues continue to go into
animal feed for chickens, other poultry, pigs, and pets
(as well as being rendered into products like tallow for
use in cosmetics, the safety of which is currently under
review). Until the federal government stops the feeding
of slaughterhouse waste, manure, and blood to all farm
animals, the safety of meat in America cannot be
guaranteed.
The hundreds of American families stricken by
sporadic CJD every year have been told that it just
occurs by random chance. Professor Collinge, the head of
the University College of London lab, noted "When you
counsel those who have the classical sporadic disease,
you tell them that it arises spontaneously out of the
blue. I guess we can no longer say that."
"We are not saying that all or even most cases of
sporadic CJD are as a result of BSE exposure," Professor
Collinge continued, "but some more recent cases may
be--the incidence of sporadic CJD has shown an upward
trend in the UK over the last decade... serious
consideration should be given to a proportion of this
rise being BSE-related. Switzerland, which has had a
substantial BSE epidemic, has noted a sharp recent
increase in sporadic CJD." In the Nineties, Switzerland
had the highest rate of Mad Cow disease in continental
Europe, and their rate of sporadic CJD doubled.
We don't know exactly what's happening to the rate of
CJD in this country, in part because CJD is not an
officially notifiable illness. Currently only a few
states have such a requirement. Because the Centers for
Disease Control (CDC) does not actively monitor the
disease on a national level, a rise similar to the one
in Europe could be missed. In spite of this, a number of
U.S. CJD clusters have already been found. In the
largest known U.S. outbreak of sporadic cases to date,
five times the expected rate was found to be associated
with cheese consumption in Pennsylvania's Lehigh Valley.
A striking increase in CJD over expected levels was also
reported in Florida and New York (Nassau County) with
anecdotal reports of clusters of deaths in Oregon and
New Jersey.
Perhaps particularly worrisome is the seeming
increase in CJD deaths among young people in this
country. In the 18 years between 1979 and 1996, only a
single case of sporadic CJD was found in someone under
30. Whereas between 1997 and 2001, five people under 30
died of sporadic CJD. So five young Americans dying in
five years, as opposed to one young case in the previous
18 years. The true prevalence of CJD among any age group
in this country remains a mystery, though, in part
because it is so commonly misdiagnosed.
The most frequent misdiagnosis of CJD among the
elderly is Alzheimer's disease. Neither CJD nor
Alzheimer's can be conclusively diagnosed without a
brain biopsy, and the symptoms and pathology of both
diseases overlap. There can be spongy changes in
Alzheimer's, for example, and senile Alzheimer's plaques
in CJD. Stanley Prusiner, the scientist who won the
Nobel Prize for his discovery of prions, speculates that
Alzheimer's may even turn out to be a prion disease as
well. In younger victims, CJD is more often misdiagnosed
as multiple sclerosis or as a severe viral infection.
Over the last 20 years the rates of Alzheimer's
disease in the United States have skyrocketed. According
to the CDC, Alzheimer's Disease is now the eighth
leading cause of death in the United States, afflicting
an estimated 4 million Americans. Twenty percent or more
of people clinically diagnosed with Alzheimer's disease,
though, are found at autopsy not to have had Alzheimer's
at all. A number of autopsy studies have shown that a
few percent of Alzheimer's deaths may in fact be CJD.
Given the new research showing that infected beef may be
responsible for some sporadic CJD, thousands of
Americans may already be dying because of Mad Cow
disease every year.
Nobel Laureate Gajdusek, for example, estimates that
1% of people showing up in Alzheimer clinics actually
have CJD. At Yale, out of a series of 46 patients
clinically diagnosed with Alzheimer's, six were proven
to have CJD at autopsy. In another study of brain
biopsies, out of a dozen patients diagnosed with
Alzheimer's according to established criteria, three of
them were actually dying from CJD. An informal survey of
neuropathologists registered a suspicion that CJD
accounts for 2-12% of all dementias in general. Two
autopsy studies showed a CJD rate among dementia deaths
of about 3%. A third study, at the University of
Pennsylvania, showed that 5% of patients diagnosed with
dementia had CJD. Although only a few hundred cases of
sporadic CJD are officially reported in the U.S.
annually, hundreds of thousands of Americans die with
dementia every year. Thousands of these deaths may
actually be from CJD caused by eating infected meat.
The incubation period for human spongiform
encephalopathies such as CJD can be decades. This means
it can be years between eating infected meat and getting
diagnosed with the death sentence of CJD. Although only
about 150 people have so far been diagnosed with variant
CJD worldwide, it will be many years before the final
death toll is known. In the United States, an unknown
number of animals are infected with Mad Cow disease,
causing an unknown number of human deaths from CJD. The
U.S. should immediately begin testing all cows destined
for human consumption, as is done in Japan, should stop
feeding slaughterhouse waste to all farm animals (see
http://organicconsumers.org/madcow/GregerBSE.cfm),
and should immediately enact an active national
surveillance program for CJD.
Five years ago this week, the Center for Food Safety,
the Humane Farming Association, the Center for Media &
Democracy, and ten families of CJD victims petitioned
the FDA and the CDC to immediately enact a national CJD
monitoring system, including the mandatory reporting of
CJD in all 50 states. The petition was denied. The CDC
argued that their passive surveillance system tracking
death certificate diagnoses was adequate. Their analysis
of death certificates in three states and two cities,
for example, showed an overall stable and typical one in
a million CJD incidence rate from 1979 to 1993. But CJD
is so often misdiagnosed, and autopsies are so
infrequently done, that this system may not provide an
accurate assessment.
In 1997, the CDC set up the National Prion Disease
Pathology Surveillance Center at Case Western Reserve
University to analyze brain tissue from CJD victims in
the U.S. in hopes of tracking any new developments. In
Europe, surveillance centers have been seeing most, if
not all, cases of CJD. The U.S. center sees less than
half. "I'm very unhappy with the numbers," laments
Pierluigi Gambetti , the director of the Center. "The
British and Germans politely smile when they see we
examine 30% or 40% of the cases," he says. "They know
unless you examine 80% or more, you are not in touch."
"The chance of losing an important case is high."
One problem is that many doctors don't even know the
Center exists. And neither the CDC nor the Center are
evidently authorized to reach out to them directly to
bolster surveillance efforts, because it's currently up
to each state individually to determine how--or even
whether--they will track the disease. In Europe, in
contrast, the national centers work directly with each
affected family and their physicians. In the U.S., most
CJD cases--even the confirmed ones--seem to just fall
through the cracks. In fact, based on the autopsy
studies at Yale and elsewhere, it seems most CJD cases
in the U.S. aren't even picked up in the first place.
Autopsy rates have dropped in the U.S. from 50% in
the Sixties to less than 10% at present. Although one
reason autopsies are rarely performed on atypical
dementia cases is that medical professionals are afraid
of catching the disease, the primary reason for the
decline in autopsy rates in general appears to be
financial. There is currently no direct reimbursement to
doctors or hospitals for doing autopsies, which often
forces the family to absorb the cost of transporting the
body to an autopsy center and having the brain samples
taken, a tab that can run upwards of $1500.
Another problem is that the National Prion Disease
Pathology Surveillance Center itself remains underfunded.
Paul Brown, medical director for the National Institutes
of Health, has described the Center's budget as
"pitiful," complaining that "there isn't any budget for
CJD surveillance." To adequately survey America's 290
million residents, "you need a lot of money." UK CJD
expert Robert Will explains, "There was a CJD meeting of
families in America in which... [the CDC] got attacked
fairly vigorously because there wasn't proper
surveillance. You could only do proper surveillance if
you have adequate resources." "I compare this to the
early days of AIDS," says protein chemist Shu Chen, who
directs the Center's lab, "when no one wanted to deal
with the crisis."
Andrew Kimbrell, the director of the Center for Food
Safety, a D.C.-based public interest group, writes,
"Given what we know now, it is unconscionable that the
CDC is not strictly monitoring these diseases." Given
the presence of Mad Cow disease in the U.S., we need to
immediately enact uniform active CJD surveillance on a
national level, provide adequate funding not only for
autopsies but also for the shipment of bodies, and
require mandatory reporting of the disease in all 50
states. In Britain, even feline spongiform
encephalopathy, the cat version of Mad Cow disease, is
an officially notifiable illness. "No one has looked for
CJD systematically in the U.S.," notes NIH medical
director Paul Brown. "Ever."
The animal agriculture industries continue to risk
public safety, and the government seems to protect the
industries' narrow business interests more than it
protects its own citizens. Internal USDA documents
retrieved through the Freedom of Information Act show
that our government did indeed consider a number of
precautionary measures as far back as 1991 to protect
the American public from Mad Cow disease. According to
one such document, however, the USDA explained that the
"disadvantage" of these measures was that "the cost to
the livestock and rendering industries would be
substantial."
Plant sources of protein for farm animals can cost up
to 30% more than cattle remains. The Cattlemen's
Association admitted a decade ago that animal
agribusiness could indeed find economically feasible
alternatives to feeding slaughterhouse waste to other
animals, but that the they did not want to set a
precedent of being ruled by "activists."
Is it a coincidence that USDA Secretary Veneman chose
Dale Moore, former chief lobbyist for the National
Cattlemen's Beef Association, as her chief of staff? Or
Alison Harrison, former director of public relations for
the Cattlemen's Association, as her official
spokeswoman? Or that one of the new Mad Cow committee
appointees is William Hueston, who was paid by the beef
industry to testify against Oprah Winfrey in hopes of
convicting her of beef "disparagement"? After a similar
conflict of interest unfolded in Britain, their entire
Ministry of Agriculture was dissolved and an independent
Food Safety Agency was created, whose sole
responsibility is to protect the public's health. Until
we learn from Britain's lesson, and until the USDA stops
treating this as a PR problem to be managed instead of a
serious global threat, millions of Americans will remain
at risk.
Michael Greger, M.D., has been the Chief BSE
Investigator for Farm Sanctuary since 1993 and the Mad
Cow Coordinator for the Organic Consumers Association
since 2001.