Palaces For The People
Saturday, January 03, 2004
Bovine Spongiform Encephalopathy and
Variant Creutzfeldt-Jakob Disease:
Background, Evolution, and
Paul Brown,* Robert G. Will,† Raymond Bradley,‡
David M. Asher,§ and Linda Detwiler¶
*National Institute of Neurological Disorders and Stroke, National Institutes
of Health, Bethesda, Maryland, USA; †National Creutzfeldt-Jakob Disease
Surveillance Unit, Western General Hospital, Edinburgh, Scotland; ‡Central
Veterinary Laboratory, New Haw, Addlestone, UK; §Center for Biologics
Evaluation and Research, Food and Drug Administration, Rockville,
Maryland, USA; ¶Animal and Plant Health Inspection Service, U.S.
Department of Agriculture, Robbinsville, New Jersey, USA
The epidemic of bovine spongiform encephalopathy (BSE) in the United Kingdom,
which began in 1986 and has affected nearly 200,000 cattle, is waning to a conclusion,
but leaves in its wake an outbreak of human Creutzfeldt-Jakob disease, most probably
resulting from the consumption of beef products contaminated by central nervous
system tissue. Although averaging only 10-15 cases a year since its first appearance in
1994, its future magnitude and geographic distribution (in countries that have imported
infected British cattle or cattle products, or have endogenous BSE) cannot yet be
predicted. The possibility that large numbers of apparently healthy persons might be
incubating the disease raises concerns about iatrogenic transmissions through
instrumentation (surgery and medical diagnostic procedures) and blood and organ
donations. Government agencies in many countries continue to implement new
measures to minimize this risk.
Testimony on Transmissible Spongiform Encephalopathies, April 4, 2001.
Testimony on Transmissible Spongiform Encephalopathies, April 4, 2001.
Richard T. Johnson, M. D.
National Institute of Neurological Disorders and Stroke
National Institutes of Health
the Senate Committee on Commerce, Science, and Transportation
Subcommittee on Consumer Affairs, Foreign Commerce and Tourism
April 4, 2001
Mr. Chairman and members of the subcommittee, good morning, and thank you for inviting me to speak to you about the transmissible spongiform encephalopathies, referred to as TSEs. My name is Dr. Richard T. Johnson. I am a Board-certified neurologist with appointments in the Departments of Neurology, Molecular Biology and Genetics, and Neuroscience at The Johns Hopkins University School of Medicine. I also hold a joint appointment in the Department of Molecular Microbiology and Immunology at The Johns Hopkins University School of Hygiene and Public Health. My professional expertise is primarily in the fields of neurovirology, neuroimmunology, and neuropathology, and in 1986-87, I served as the primary neurology consultant for a Public Health Service interagency, epidemiological study of human growth hormone and Creutzfeldt-Jakob Disease. I am currently serving as an expert consultant to the National Institute of Neurological Disorders and Stroke and to the National Institutes of Health on the TSEs.
The TSEs are fatal neurodegenerative diseases of humans and animals. They share a characteristic brain pathology which has the appearance of "spongy" holes in the brain; a long incubation period - sometimes decades long; and the probable causative agent - proteinaceous infectious particles - known as "prions." Prions are transmissible particles that are devoid of nucleic acid and seem to be composed exclusively of a modified protein. According to the prion hypothesis, an abnormal conformation, or folding, of the normal protein carries the disease, and recruits normal prion proteins to the harmful conformation. The notion of an infectious agent that lacks the nucleic acids - the molecules which carry hereditary traits from one generation to the next and trigger the production of specific proteins - is revolutionary, but the preponderance of scientific evidence supports this hypothesis.
Animal TSEs include bovine spongiform encephalopathy, known as BSE or "mad cow disease," scrapie in sheep, and varying forms which occur in cats, mink, elk, deer, and exotic zoo animals. Creutzfeldt-Jakob disease, known as CJD, is the most common human TSE; other lesser known and rarer human forms include Fatal Familial Insomnia and Kuru. A distinct new variant form of CJD - vCJD - has been recognized only since 1996, the onset of illness in the first case having occurred in early 1994. I will briefly discuss the symptoms, incidence, and likely routes of transmission of classic CJD first, and then discuss variant CJD and its link with BSE.
In the early stages of the disease, CJD patients may have failing memory, behavior changes, impaired coordination and visual disturbances. As the illness progresses, mental deterioration becomes pronounced, and involuntary movements, blindness, weakness of extremities, and, ultimately, coma may occur. CJD usually becomes apparent in later life, and the disease typically leads to death within one year following the onset of symptoms - in the United States, the mean age of death is 67 years.
CJD, while the most common human TSE, is still very rare; it afflicts only about one in a million people each year. About 90 percent of these cases are sporadic - meaning they appear to occur spontaneously, about another ten percent are an inherited genetic disorder, and less than one percent are transmitted. The failure to find increased incidence of CJD in persons who have come into even close and regular contact with CJD patients suggests the disease is not contagious through normal routes. However, inadvertent human-to-human transmission has been reported from corneal transplantation; direct contact with contaminated medical and surgical instruments; inoculation of growth hormone prepared from contaminated cadaver pituitary glands; and grafts of dura mater - the tough fibrous membrane covering the brain and the spinal cord and lining the inner surface of the skull - obtained from cadaveric donors who had unsuspected CJD.
Variant CJD is also fatal, but is clinically and pathologically distinct from classic CJD. Clinically, vCJD patients have an earlier age of onset - mean age at death is 29 years compared to 67 years in CJD. They usually present with behavioral changes, loss of the ability to coordinate muscular movements, and peripheral sensory disturbances such as loss of sensation, rather than changes in mental activity and thinking ability, and do not show the usual brain wave activity changes of CJD. Variant CJD patients have a longer duration of illness from onset of symptoms to death - median survival is 14 months in vCJD compared to four months in CJD. Pathologically, an unusual form of plaque is present in the brains of people with vCJD: a florid or "daisy" plaque in which an amyloid core - a hard, waxy deposit that results from the degeneration of tissue - is surrounded by "petals" of spongiform change.
As of April 2, 2001, the UK has reported 97 probable or confirmed cases of deaths from vCJD since 1995, and a few more have been reported in continental Europe. No cases of vCJD have been reported in the United States. Because of the timing of the appearance of vCJD in the UK in relation to the BSE epidemic, a link between the two diseases was deemed likely. So, I will briefly discuss BSE and the evidence in support of this link, as well as the concerns it raises.
We do not know exactly how BSE, or "mad cow disease" as it frequently referred to in media reports, originated, but we do know with some certainty how it spread and reached epidemic proportions in the UK. As explored in an article in the January-February 2001 volume of the journal, Emerging Infectious Diseases, by Dr. Paul Brown and others, one theory for the origin of BSE is that it originated from scrapie, an endemic TSE of sheep and goats that has been recognized in Europe since the mid-18th century, and has since spread to most sheep-breeding countries. Until 1988 in the UK, the rendered carcasses of livestock, including sheep, were fed to ruminants, such as cattle, and other animals as a protein-rich nutritional supplement. Although not proven, it appears likely that changes in the UK's rendering process around 1980 allowed the causative agent in infected carcasses to survive, contaminate the protein supplement, and infect cattle. Cattle carcasses and carcass wastes were then recycled through the rendering plants, increasing the levels of the now cattle-adapted pathogen in the protein supplement and eventually causing a full-scale BSE epidemic. An alternative explanation, proposed in the recent UK "Report of the BSE Inquiry" which investigated the emergence and identification of BSE and vCJD, is that a spontaneous disease-causing mutation occurred in cattle in the 1970s. Either of these hypotheses satisfies the need for a causative agent to survive the altered rendering process, and to escalate through recycling of an ever-larger number of infected carcasses.
BSE is not restricted to the UK; cases have been reported in France, Portugal, Germany, Spain, and the Republic of Ireland, among others, probably as a result of imported live animals or livestock food supplements. However, no documented case of BSE has occurred in the United States or other countries that have historically imported little or no live cattle, beef products, or livestock nutritional supplements from the UK, even though rendering procedures in other countries underwent changes similar to those in the UK during the late 1970s.
While there were concerns about human infection resulting from the BSE epidemic, these were generally allayed by the presumption that BSE originated from scrapie, and scrapie was not a human pathogen. UK surveillance and epidemiological studies further muted these concerns. During the 10 years after the first case of BSE was identified, cases of CJD in the UK did not increase in groups at high risk, and continued to occur in the general population at the same rate and with the same spectrum of clinical and neuropathologic features as before the appearance of BSE. However, then the onset of the variant form started to appear in 1994, and the suspected link between BSE and vCJD has now been convincingly established. Laboratory studies have shown the distinctive biological and molecular features of the pathologic agent transmitted from BSE-infected cattle and human cases of vCJD to be identical. The source of transmission appears to have been beef, with infection most probably resulting from consumption of beef products contaminated by nervous system tissue.
Although the amount of infectious tissue ingested is probably a critical factor in the transmission of BSE to humans in the form of vCJD, a human genetic susceptibility in the prion protein gene -PRNP - appears to play an important role in infection. It is possible that a very specific genetic constitution, or genotype, is necessary for BSE to be able to replicate in a human as vCJD. It is also possible that certain variations of this susceptible genotype are comparatively resistant to the disease, and only become ill after longer incubation periods. As noted in Dr. Brown's recent article cited above, the difference between the incidence of BSE and vCJD may be due to limited exposure to very small infectious doses that, except in genetically susceptible persons, cannot surmount the combined effects of a species barrier - from cattle to human - and a comparatively inefficient route of infection - the digestive tract as opposed to direct central nervous system contact. On the other hand, the ultimate extent of the vCJD outbreak is unknown largely because the incubation period for vCJD is unknown.
Mr. Chairman, I know that you have an appropriately keen interest in measures being taken to prevent the occurrence and propagation of BSE in the United States. An essential aspect of any such preventive efforts is detection and diagnosis, the precision of which can only extend as far as our understanding of the nature of the disease. The NIH has a long history of research on the TSEs. This is reflected in the awarding of the 1976 Nobel Prize for intramural work begun in the 1950's that established the transmissibility of these diseases, and of the 1997 Nobel Prize for extramural work on the prion theory. Recent and ongoing studies address many aspects of TSEs and prion biology including the normal functions of the prion protein, animal models of TSEs, the molecular mechanisms of prion diseases, the role of genetics, and exploratory studies of therapeutic strategies. Finally, a major contract effort is working to develop presymptomatic tests.
This concludes my testimony. I would be pleased to respond to any questions you might have.
Appendix: (134Kb PDF)
Paul Brown, Robert G. Will, Raymond Bradley, David M. Asher, and Linda Detwiler, "Bovine spongiform encephalopathy and variant Creutzfeldt-Jakob disease: background, evolution, and current concerns." Emerging Infectious Diseases, 2001 Jan-Feb;7(1):6-16.
Reviewed July 1, 2001
NINDS Transmissible Spongiform Encephalopathies Information Page
NINDS Transmissible Spongiform Encephalopathies Information Page
Synonym(s): Prion Diseases
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Table of Contents (click to jump to sections)
What are Transmissible Spongiform Encephalopathies?
Is there any treatment?
What is the prognosis?
What research is being done?
Related NINDS Publications and Information
What are Transmissible Spongiform Encephalopathies?
Transmissible spongiform encephalopathies (TSEs), also known as prion diseases, are a group of rare degenerative brain disorders characterized by tiny holes that give the brain a "spongy" appearance. These holes can be seen when brain tissue is viewed under a microscope.
Creutzfeldt-Jakob disease (CJD) is the most well-known of the human TSEs. It is a rare type of dementia that affects about one in every one million people each year. Other human TSEs include kuru, fatal familial insomnia (FFI), and Gerstmann-Straussler-Scheinker disease (GSS). Kuru was identified in people of an isolated tribe in Papua New Guinea and has now almost disappeared. FFI and GSS are extremely rare hereditary diseases, found in just a few families around the world. A new type of CJD, called variant CJD (vCJD), was first described in 1996 and has been found in Great Britain and several other European countries. The initial symptoms of vCJD are different from those of classic CJD and the disorder typically occurs in younger patients. Research suggests that vCJD may have resulted from human consumption of beef from cattle with a TSE disease called bovine spongiform encephalopathy (BSE), also known as "mad cow disease." Other TSEs found in animals include scrapie, which affects sheep and goats; chronic wasting disease, which affects elk and deer; and transmissible mink encephalopathy. In a few rare cases, TSEs have occurred in other mammals such as zoo animals. These cases are probably caused by contaminated feed. CJD and other TSEs also can be transmitted experimentally to mice and other animals in the laboratory. ...
Don't Have a Cow
Don't Have a Cow
There's no science to justify the panic over the safety of eating beef
[STEVE MILLOY IS A PAID LOBBIEST FOR NUMEROUS DIRTY INDUSTRIES. He has been in the service of the tobacco, oil, and pharm-chem companies whom have been fined billions of dollars for injuring American Citizens -- and now he is BEEF spokeman. CATO was cofounded by the killer Charles G, Koch of Koch Industries. This is their PR spin to cram poison meat down your throat.]
By Steven Milloy, Steven Milloy is an adjunct scholar at the Cato Institute and the author of "Junk Science Judo: Self-Defense Against Health Scares and Scams" (Cato Institute, 2001).
The "mad cow" disease diagnosed in a U.S. cow has set off a new round of predictable, but groundless, panic.
Foreign governments promptly banned imports of U.S. beef. Investors dumped the stocks of beef- related companies. And, of course, what health scare would be complete without hyperventilating calls for even more government oversight of an already highly regulated industry?
There's no question that bovine spongiform encephalopathy, or BSE — commonly called mad cow disease — is a neurological disease in cattle. But the notion that people can contract a human form of mad cow by eating beef from infected cattle is more bun than burger.
The first epidemic of mad cow broke out among cattle in Britain in 1986. Eight years later, human cases of a supposedly novel brain ailment, called new variant Creutzfeldt-Jakob disease, or variant CJD, began appearing in Britain.
Though laboratory testing seemed to indicate that BSE and variant CJD were similar, no one could determine with certainty whether and how the BSE epidemic was related to the "human mad cow" cases.
There were no geographic areas in Britain with a significantly higher incidence of variant CJD cases, and there were no cases of variant CJD among apparently high-risk groups such as farmers, slaughterhouse workers and butchers.
When researchers considered the possibility that variant Creutzfeldt-Jakob disease was caused by consumption of beef from BSE-infected cattle, no correlations could be established between variant CJD and any specific meat or dairy product. No one could even establish whether any of the variant CJD victims ever consumed beef from diseased cattle.
Some researchers nevertheless became fixated on the idea that consumption of infected beef was the culprit behind variant Creutzfeldt-Jakob, especially after it was discovered that 1980s slaughterhouse and meat preparation practices inadvertently might have allowed tissue from diseased cattle to be mixed into packaged meat products such as hot dogs, sausages, beef patties, luncheon meat and the like.
That mere hypothetical possibility spawned mad cow mania.
But the infected-beef hypothesis doesn't explain why variant CJD tends to occur in young people; most cases have occurred among 15- to 25-year-olds. And it doesn't offer the slightest clue as to why only about 130 variant CJD cases have occurred in a British population of 60 million people who are exposed to millions of pounds of potentially contaminated beef products.
Some have suggested that a kind of "epidemiological Russian roulette" is at work, where consumption of infected beef results in rare and randomly distributed cases of variant Creutzfeldt-Jakob disease. However, the Russian roulette explanation is not a scientific one and should not be the basis of public alarm or public policy. Despite that, the infected beef theory has mutated into an orthodoxy in the medical and public health community that few have been brave enough to challenge.
One public health expert in Britain, George A. Venters, did manage to publish an article in the British Medical Journal in October 2001 titled "New variant Creutzfeldt-Jakob disease: The epidemic that never was." Venters maintains that the infected beef theory is simply wrong. He challenges the biological plausibility of BSE causing variant CJD because there is no direct evidence that the supposed vehicle of BSE infection — a special protein called a prion — is infectious. Nor is there direct evidence that BSE prions survive cooking, digestion and the human immune system.
After discussing the numerous deficiencies in the BSE-Creutzfeldt-Jakob hypothesis, Venters observed: "The evidence that has been amassed is directed toward confirming the [BSE-CJD] hypothesis rather than testing it. Salient contrary information has either been played down or ignored."
No doubt much of this rush to judgment was spurred by the 1997 Nobel Prize awarded to the developer of the theory that prions are infectious, Dr. Stanley Prusiner of UC San Francisco. Although his work associates prions with mad cow and Creutzfeldt-Jakob among other diseases, the actual mechanism of infection remains unknown. So prestigious prizes aside, there is as of now no demonstrable causal link between mad cows and human health problems.
BSE-infected cattle should be isolated and destroyed to ensure there is no further spread of mad cow disease among the animals. There is no dispute about this common-sense animal health measure. But variant Creutzfeldt-Jakob is a rare, isolated and apparently random disease of unknown origin. Those conditions don't justify the current panic about the safety of the beef supply.
Mad Cow Variant That Hits Humans Is a Puzzle (washingtonpost.com)
By Rob Stein
Washington Post Staff Writer
Saturday, January 3, 2004; Page A01
She had just graduated from college when the frightening symptoms started to surface. The vivacious, easygoing 22-year-old suddenly became inexplicably irritable and short-tempered. Then her memory started failing. Her right hand began to tremble. Her leg started to shake, and her balance gave way.
"She just cried and cried and cried," said the Miami woman's father, who asked that his daughter be identified only by her first name, Charlene. "She knew she was sick, but she didn't know what it was."
Within six months, Charlene was incoherent and helpless, unable to speak or control her bodily functions. Today, two years after the first symptoms appeared, she lies bedridden, her brain ravaged. She is fed through a tube in her stomach and has no hope of surviving.
"She went down very quickly. She lost awareness. She doesn't know where she is and who anyone is," said her father, Patrick. "Every day is hard."
Charlene is the only person in the United States confirmed to have the human form of mad cow disease, in which a misshapen infectious protein inexorably erodes the brain. She is believed to have contracted the insidious disease by eating infected beef during her first 13 years of life, when her family was living in Britain.
Charlene's story is the kind of tragedy that the United States is desperately trying to avoid after the discovery of the first U.S. cow carrying the infection.
"I'm terrified that this is going to happen again. It's like being in the U.K. again, watching this all over again," Patrick said. "I'm worried that people may be eating beef that is contaminated and that down the road people are going to start to die from this disease."
Government officials and many independent experts stress that even with the long-feared detection of an infected cow in this country, existing safeguards mean the risk that anyone eating U.S. beef will face Charlene's fate remains extremely remote. Agriculture officials announced drastic new measures this week in the hopes of erasing any possibility of danger.
But as experts debate the effectiveness of the new protections, try to figure out how the Holstein became infected and search for other contaminated cows that may be in the food supply, the discovery of the infected animal has focused attention on the many uncertainties about the illness and on how well the government monitors for homegrown cases.
"I think the occurrence of mad cow disease is something of a wake-up call that no matter how we insulate ourselves, we need to be increasingly vigilant and fill in whatever gaps there might be," said Raymond Roos of the University of Chicago, who studies the disease.
Worldwide, 153 cases of the human form of mad cow disease have been reported. The overwhelming majority -- 143 -- occurred in England, where the disease was first detected in 1996. Six cases have been documented in France, and one each has been reported in Italy, Ireland, Canada and the United States. All have been linked to the mad cow epidemic in England in the 1980s.
In cows, the disease is officially known as bovine spongiform encephalopathy (BSE) -- "spongiform" because the disease makes the brain look like a hole-riddled sponge. In humans, the disease is called variant Creutzfeldt-Jakob disease (vCJD). It is named after Creutzfeldt-Jakob disease (CJD), a similar but distinct brain malady first identified in Germany in 1920.
CJD is one of a few diseases caused by prions. Prions are strange, normally harmless proteins found in the brain that contort into a shape that makes them lethal to nerve cells. In CJD, which occurs in about 1 out of every 1 million people, the malformation occurs spontaneously for reasons that remain a mystery. Victims quickly and progressively lose their ability to think and control their bodies. It is untreatable and invariably fatal.
The disease almost always hits people in their fifties, sixties and seventies. In the late 1990s, however, British doctors noticed that unusual cases appeared to be striking people in their twenties and thirties. Scientists traced the baffling cases to meat from cows stricken by mad cow disease -- which is also caused by prions.
Until then, the only known cases of transmitted CJD involved transplant patients who were given nervous system tissue or short children who received injections of growth hormone derived unknowingly from infected people. It is also passed down through generations in rare families.
In 1996, Britain faced the possibility of a devastating epidemic of the first prion disease known to be spread by eating infected animals. U.S. officials began monitoring the incidence of CJD in this country and started investigating unusual cases.
"Because of travel to the United Kingdom, some Americans may have been exposed to BSE," said Ermias Belay, a medical epidemiologist at the federal Centers for Disease Control and Prevention in Atlanta. "It's an awful disease."
The key was to differentiate between CJD, the spontaneous form of the disease, and vCJD, the human form of mad cow disease. Although the two diseases are similar, they differ in ways aside from the age of typical victims.
The first symptoms of CJD are usually memory lapses and difficulty standing, walking and talking. Victims deteriorate rapidly, becoming bedridden in weeks or months and falling into a coma before they die, usually within a year.
In contrast, vCJD patients tend first to develop psychiatric symptoms such as Charlene's -- depression, anxiety, withdrawal. They also often have severe pain or tingling and burning sensations in the legs before they begin to lose the ability to stand, walk and talk. As in Charlene's case, the agony often stretches over two to four years before death.
Magnetic resonance imaging (MRI) can frequently detect unique changes in the brain that distinguish vCJD from CJD. Sometimes the prions can be found in the tonsils of vCJD victims, as was the case with Charlene. An electroencephalogram (EEG) can sometimes spot a distinctive brain wave pattern in CJD patients that does not occur in vCJD patients.
But the only way to make a definitive diagnosis is to do a detailed examination of the brain after death. The brains of vCJD patients have telltale deposits of plaque. There are also subtle differences in the prion proteins that can be detected by chemical analysis.
In the past six years, doctors have shipped samples from the brains of 732 patients who have died from suspicious diseases to the National Prion Disease Pathology Surveillance Center, which the CDC established at Case Western Reserve University in Cleveland. Scientists conduct a battery of tests for signs of vCJD and another disease caused by prions that affects elk and deer, called chronic wasting disease. It has not been found in humans.
Some skeptics say odd cases or clusters of cases of CJD have occurred in the United States that may be homegrown vCJD, but the CDC and other experts maintain that none has been confirmed.
"We think we are in the best position to discover if there is an atypical case," said Pierluigi Gambetti, who directs the Cleveland center. "We have not seen one case of variant CJD that was a real American indigenous case."
But Gambetti acknowledged that he gets samples from only perhaps half of the cases of CJD that would be expected to occur each year in the United States.
"It's not complete surveillance. It's like you go to the airport, and half the people go unchecked. You would not be happy to fly in an airplane where half the people have not been checked at all," Gambetti said. "If we want to protect Americans, we need to examine many more cases."
Nevertheless, experts doubt that large numbers of cases are escaping detection in this country. The main reason is the relatively small number of cases that have occurred in Britain even though more than 1 million infected cows may have entered the food supply there.
HUMAN EVENTS ONLINE :: Page 3 -- Mad Cow Meets Bad Bureaucrats
Page 3 -- Mad Cow Meets Bad Bureaucrats
Posted Jan 2, 2004
The federal government does many things that are unconstitutional and unnecessary—from interfering with local public schools to providing seniors with tax-subsidized drugs. But it does have constitutional authority to defend our borders generally and to regulate foreign and interstate commerce. That would seem to give it some responsibility for protecting the U.S. from diseased foreign foods.
The good news last week was that the mad cow discovered in Washington State appears to have been born in Canada before the U.S. in 1997 imposed a ban on feeding cattle with meal made from cattle parts—the means by which mad cow disease spreads. The bad news is the Food and Drug Administration enforced this ban about as well as—well, about as well as the Department of Homeland Security enforces the immigration laws.
On Jan. 25, 2002, the General Accounting Office published a prophetic and scathing report on the FDA's mad-cow performance record. Here are some telling excerpts from the report, entitled, "Mad Cow Disease—Improvements in the Animal Feed Ban and Other Regulatory Areas Would Strengthen U.S. Prevention Efforts."
While BSE [Mad Cow Disease] has not been found in the United States, federal actions do not sufficiently ensure that all BSE-infected animals or products are kept out or that if BSE were found, it would be detected promptly and not spread to other cattle through animal feed or enter the human food supply. . . .
According to FDA 's October 2001 quarterly update that summarized results of feed ban inspections, 364 [animal-feed-manufacturing] firms were out of compliance. In addition, FDA believes that not all firms that should be subject to the ban have been identified and inspected, at least 1,200 or more based on industry estimates. However, we could not verify these data because we found significant flaws in FDA's database, which we discuss later in this report. FDA did not take prompt enforcement action to compel firms to comply with the feed ban. When we began this study, in April 2001, the only enforcement action FDA had taken was to issue two warning letters in 1999.
The first letter was issued in May 1999—21 months after inspections began.
However, since inspections began in 1997, FDA has reported hundreds of firms out of compliance—most often for failure to meet requirements to label feed that contained prohibited proteins or for including prohibited proteins in cattle feed.
In our analysis of individual inspection forms, we found several instances in which firms were out of compliance in repeated inspections, yet FDA had not issued a warning letter. We also found instances in which firms were out of compliance but had not been re-inspected for a year or more—and in some cases for more than 2 years.
Between February and November 2001, FDA issued warning letters to another 48 firms. In addition, 17 firms voluntarily recalled feed, including 9 that had been issued a warning letter. As of Nov. 30, 2001, FDA or states had re-inspected 33 of the total of 50 firms that had been issued warning letters (2 in 1999 and 48 in 2001). Six of the firms were still out of compliance on re-inspection.
FDA has no enforcement strategy for feed ban compliance that includes a hierarchy of enforcement actions, criteria for actions to be taken, time frames for firms to correct violations, and time frames for follow-up inspections to confirm that violations have been corrected.
According to FDA, rather than taking enforcement actions, it has emphasized educating firms subject to the feed ban about the ban's requirements and working with those firms to establish cooperative relationships.
FDA reported that some states might have taken enforcement actions, including requiring firms to recall noncompliant feed. However, FDA does not track enforcement actions taken by states; therefore, it does not know the extent of such actions.
Even if FDA were to actively enforce the feed ban, its inspection database is so severely flawed that—until corrected—it should not be used to assess compliance...
From our review of FDA's database of 12,046 feed ban inspection records (as of Oct. 26, 2001), we found records lacked unique identifiers, were incomplete, contained inconsistent or inaccurate information, and were not entered into the database in a timely manner. Examples of the severe flaws we found include:
# Entries for 5,446 inspections—or about 45% of all inspections—lack information to uniquely identify individual firms. As a result, the data cannot be used to reliably determine the number of firms inspected, compliance trends over time, or the inspection history of an individual firm. . . .
# Entries for 301 inspections of firms that handle prohibited proteins contain no response to whether feed was properly labeled; entries for 438 inspections of firms that handled both prohibited and non-prohibited proteins had no response to whether prohibited proteins were included in feed intended for cattle.
# Entries where responses to questions about feed labeling or whether prohibited proteins were included in feed intended for cattle indicated that the firms were in compliance; however, inspectors' notes contained in other sections of the database contradicted the responses and indicated the firms were not in compliance.
# Inspections were not entered into the database. In assessing the warning letters, we discovered references to inspections that do not appear in the database. In fact, the inspection record for the firm that received the first warning letter—in May 1999—does not appear in the database. . . .
# The database is incomplete. It does not include all firms subject to the feed ban. FDA officials relied on the personal knowledge of state and FDA field staff and on membership lists from industry groups to identify and locate firms. However, our review of membership records for the National Renderers Association—for the years 1998 to 2001—disclosed 21 rendering firms that were not in FDA's database. According to association records, those firms process meat and bone meal and other products that could contain proteins subject to the feed ban.
FDA did not count data entries with blanks—no responses—in the selected data fields it uses when it reports on compliance. Therefore, when FDA provided compliance information to the Congress—and when it publishes that information electronically—the data are misleading and the number of firms identified as out of compliance are undercounted...
An FDA official told us that the database was not originally intended to track compliance of individual firms, but rather to guide the agency's efforts to educate firms subject to the ban by illustrating particular states or practices that needed more intensive focus. However, FDA has no information system other than the inspection database to track compliance with the feed ban.
FDA has not placed a priority on oversight of the feed ban. From the implementation of the feed ban in August 1997 until early 2001, one person in FDA 's Center for Veterinary Medicine was responsible for feed ban management...
BSE and vCJD [Creutzfeldt-Jakob Disease] are devastating, incurable, inevitably fatal diseases. If they enter the country, they can bring dire economic consequences to the cattle and beef industries. Therefore, forceful federal prevention efforts are warranted to keep BSE away from U.S. shores. Nevertheless, Customs has reported significant error rates in importer-provided information for BSE-risk shipments, import controls over bulk mail are weak, and inspection capacity has not kept pace with the growth in imports. Because of these import weaknesses—and because BSE may have entered in imports from countries that have since developed the disease—BSE may be silently incubating somewhere in the United States. If that is the case, then FDA 's failure to enforce the feed ban may already have placed U.S. herds and, in turn, the human food supply at risk.
Mad cow disease - The Washington Times: Editorials/OP-ED
Mad cow disease
By Michael Greger
According to the Center for Disease Control, 76 million Americans every year get food poisoning. If you do the math, that's about 1 in 4 of us every year. You know that "24-hour flu" you had this year? Well, you should know that there's no such thing as a 24-hour flu. You probably got food poisoning. From last year's Listeria and E. coli to a burgeoning antibiotic-resistant salmonella, in today's food safety lottery there's a 1 in 840 chance that we Americans will be hospitalized and a 1 in 55,000 chance that we will die from food-borne illness every year.
But E. coli? Easily destroyed by proper cooking. This new super-salmonella threat? Luckily, we still have big-gun antibiotics to kill it. Even bugs like Listeria are pretty wimpy pathogens. After millennia of humans eating the bodies and bodily fluids of other animals, you'd think Mother Nature could cook up a nastier microbe.
Well, let's use our imagination. What if there was something in our food supply that wasn't affected by cooking or antibiotics? Something new and undetectable, perhaps?Someultimate pathogen, practically indestructible, evading the immune system and maybe causing some, oh, invariably fatal neurodegenerative disease? Welcome to the world of bovine spongiform encephalopathy (BSE), or mad cow disease.
The pathogen thought responsible for this disease is not a virus, not a fungus, not a bacteria, but thought to be a prion — an infectious protein. Because of their unique structure, prions are practically invulnerable. They can remain infectious for years in the soil. They are not adequately destroyed by cooking, canning, freezing, usable doses of radiation, digestive enzymes or stomach acid. Even heat sterilization, household bleach and formaldehyde sterilization have little or no effect. One study raised the disturbing question of whether even incineration could guarantee the inactivation of prions.
That study was performed by Paul Brown, medical director for the U.S. Public Health Service, who found prions could remain infectious even after exposure to temperatures over 1000 degrees Fahrenheit. That's hot enough to melt lead. Prions have been called the smallest, most lethal biological entities in the world.
It is perhaps not surprising that one cow in the United States has mad cow disease, given that certain cannibalistic practices of feeding slaughterhouse waste to livestock have been allowed to continue. What is surprising, given the inadequacy of our surveillance program, is that we found a case at all. Europe and Japan follow World Health Organization guidelines and test every downer cow for mad cow disease. By contrast, the United States has tested less than 2 percent of downers over the last decade. In 2003, we increased that testing, but only to about 10 percent.
Regardless of whether downer cows were tested or not, most of these animals — cows too sick or injured to even walk — have ended up on our dinner plates.
The Department of Agriculture (USDA) decision to finally remove downer cattle from the human food supply is a welcome departure from the past week's Pollyanna public relations, but it can only be effective in conjunction with a dramatic increase in surveillance testing. It seems the only reason we picked up the recent case was that the cow suffered a birthing injury.
Had she not, she presumably would not have been tested at all. Indeed in Europe, where they test one out of every four cows, and Japan, where they test 100 percent of all cattle bound for human consumption, they have found a number of cases of mad cow disease in animals who appeared perfectly healthy.
The discovery of a case of mad cow disease in the United States highlights how ineffective current safeguards are in North America. The United States banned the feeding of the muscles and bones of most animals to cows and sheep back in 1997, but unlike Europe left gaping loopholes in the law. For example, blood is currently exempted from the U.S. feed regulations. You can still collect cow's blood at the slaughterhouse and feed blood concentrates to calves. In modern agribusiness, calves may be removed from their mothers immediately after birth, so the calves are fed milk replacer, which is often supplemented with cow blood protein. Weaned calves and young pigs may also have cattle blood sprayed directly on their feed to save money on feed costs. The reason that the American Red Cross bars blood donations from people who spent substantial time in Western Europe is because we now know blood to be infectious.
The U.S. feed regulations also still allow the feeding of rendered cattle remains to pigs, for example, and then the pig remains can be fed back to cattle. Or rendered cattle remains can be fed to chickens, and then the chicken litter, or manure, can be legally fed back to the cows. So, the fact that the most infectious tissues of the recently reported U.S. mad cow case — the brain, spinal cord, and intestines — "were removed from this animal and sent to rendering" is not necessarily reassuring, given that contaminated tissues are routinely still fed to pigs, chickens and other animals who may cycle the disease back to cows, or perhaps even carry the deadly prions directly to human consumers. Where do we think all the brains, spinal cords and downer cows are going to go now?
Even with the loopholes closed, though, the feed ban will only be as effective as its enforcement. Hundreds of feed mills and rendering plants have violated the feed ban regulation. In 2002, the United States General Accounting Office (GAO) released a report on the inadequacy of our defenses against mad cow disease, and concluded that the FDA's failure to enforce the feed ban may already have "placed U.S. herds and, in turn, the human food supply at risk."
In Canada, authorities were at least able to reassure the public that the infected downer cow they discovered was excluded from the human food chain and only rendered into animal feed. U.S. officials can't offer the same reassurance, as the mad cow we discovered was likely ground into hamburger and at least some of her eaten. How then, can the USDA and the beef industry insist that the American beef supply is still safe? They argue that the infectious prions that cause the disease are only found in the brain and nervous tissue, not in the muscles, not in the meat. This can be viewed as misleading on two counts.
First, Americans do eat bovine central nervous system tissue. The GAO report noted, for example, that beef stock, beef extract and beef flavoring are frequently made by boiling the skeletal remains of the animals, including the spinal column. According to the consumer advocacy organization Center for Science in the Public Interest, spinal cord contamination may also be found in U.S. hot dogs, hamburgers, pizza toppings, and taco fillings. In fact, a 2002 USDA survey showed that approximately 35 percent of high-risk meat products tested positive for central nervous system tissues. Thankfully, the new USDA recommendations — if enforced — should keep these most infectious tissues off our plates.
Even if Americans just stick to steak, though, they may not be shielded from risk. There are a number of ways the muscle tissue can get contaminated by potentially highly infectious brain or spinal cord tissue. For example, the head trauma caused by attempts to stun the animals prior to slaughter (even with the non-air injection stunners) commonly blows tiny fragments of brain throughout the bodies of these animals. Even without nervous tissue contamination, though, there is now evidence that the muscle tissue itself could be infectious. Dr. Stanley Prusiner, the scientist who won the Nobel Prize in Medicine for his discovery of prions, proved in 2002 that prions can build up in muscle tissue, a finding confirmed by follow-up studies in Germany. And in November, the New England Journal of Medicine published a study in which Swiss scientists found prions in the muscles of human spongiform encephalopathy victims on autopsy.
Despite these shortcomings, Agriculture Secretary Ann Veneman and Washington's governor both assured the public that they were still having beef for Christmas, reminiscent of the 1990 fiasco in which the British agriculture minister appeared on TV urging his 4-year-old daughter to eat a hamburger. Four years later, young people in Britain were dying from an invariably fatal neurodegenerative disease called variant Creutzfeldt-Jakob Disease — the human equivalent of mad cow disease — which they contracted through the consumption of infected beef. With an incubation period up to decades long, no one knows how high the final human death toll will be.
One of the problems, as many English pundits saw it, is that the British Ministry of Agriculture represented the interests of both consumers and the beef industry. A similar conflict of interest exists here in the United States. USDA's mandate is to promote agricultural products, but also to protect consumer health.
Mrs.Venemanherselfappointed Dale Moore, former chief lobbyist for the National Cattlemen's Beef Association, as her chief of staff. In the end, I'm afraid this crisis may show to what length governments will go to prevent financial harm to powerful lobbies in general, and in doing so risk immeasurable harm to those they claim to represent.
Michael Greger, M.D., is the chief BSE investigator for Farm Sanctuary and Mad Cow Coordinator for the Organic Consumers Association.
Op-Ed Contributor: The Cow Jumped Over the U.S.D.A.
The Cow Jumped Over the U.S.D.A.
By ERIC SCHLOSSER
Published: January 2, 2004
lisa Harrison has worked tirelessly the last two weeks to spread the message that bovine spongiform encephalopathy, or mad cow disease, is not a risk to American consumers. As spokeswoman for Agriculture Secretary Ann M. Veneman, Ms. Harrison has helped guide news coverage of the mad cow crisis, issuing statements, managing press conferences and reassuring the world that American beef is safe.
For her, it's a familiar message. Before joining the department, Ms. Harrison was director of public relations for the National Cattlemen's Beef Association, the beef industry's largest trade group, where she battled government food safety efforts, criticized Oprah Winfrey for raising health questions about American hamburgers, and sent out press releases with titles like "Mad Cow Disease Not a Problem in the U.S."
Ms. Harrison may well be a decent and sincere person who feels she has the public's best interest at heart. Nonetheless, her effortless transition from the cattlemen's lobby to the Agriculture Department is a fine symbol of all that is wrong with America's food safety system. Right now you'd have a hard time finding a federal agency more completely dominated by the industry it was created to regulate. Dale Moore, Ms. Veneman's chief of staff, was previously the chief lobbyist for the cattlemen's association. Other veterans of that group have high-ranking jobs at the department, as do former meat-packing executives and a former president of the National Pork Producers Council.
The Agriculture Department has a dual, often contradictory mandate: to promote the sale of meat on behalf of American producers and to guarantee that American meat is safe on behalf of consumers. For too long the emphasis has been on commerce, at the expense of safety. The safeguards against mad cow that Ms. Veneman announced on Tuesday — including the elimination of "downer cattle" (cows that cannot walk) from the food chain, the removal of high-risk material like spinal cords from meat processing, the promise to introduce a system to trace cattle back to the ranch — have long been demanded by consumer groups. Their belated introduction seems to have been largely motivated by the desire to have foreign countries lift restrictions on American beef imports.
Worse, on Wednesday Ms. Veneman ruled out the the most important step to protect Americans from mad cow disease: a large-scale program to test the nation's cattle for bovine spongiform encephalopathy.
The beef industry has fought for nearly two decades against government testing for any dangerous pathogens, and it isn't hard to guess why: when there is no true grasp of how far and wide a food-borne pathogen has spread, there's no obligation to bear the cost of dealing with it.
The United States Department of Agriculture is by no means the first such body to be captured by industry groups. In Europe and Japan the spread of disease was facilitated by the repeated failure of government ministries to act on behalf of consumers.
In Britain, where mad cow disease was discovered, the ministry of agriculture misled the public about the risks of the disease from the very beginning. In December 1986, the first government memo on the new pathogen warned that it might have "severe repercussions to the export trade and possibly also for humans" and thus all news of it was to be kept "confidential." Ten years later, when Britons began to fall sick with a new variant of Creutzfeldt-Jakob syndrome, thought to be the human form of mad cow, Agriculture Minister Douglas Hogg assured them that "British beef is wholly safe." It was something of a shock, three months later, when the health minister, Stephen Dorrell, told Parliament that mad cow disease might indeed be able to cross the species barrier and sicken human beings.
In the wake of that scandal, France, Spain, Italy, Germany and Japan banned imports of British beef — yet they denied for years there was any risk of mad cow disease among their own cattle. Those denials proved false, once widespread testing for the disease was introduced. An investigation by the French Senate in 2001 found that the Agriculture Ministry minimized the threat of mad cow and "constantly sought to prevent or delay the introduction of precautionary measures" that "might have had an adverse effect on the competitiveness of the agri-foodstuffs industry." In Tokyo, a similar mad cow investigation in 2002 accused the Japanese Agriculture Ministry of "serious maladministration" and concluded that it had "always considered the immediate interests of producers in its policy judgments."
Instead of learning from the mistakes of other countries, America now seems to be repeating them. In the past week much has been made of the "firewall" now protecting American cattle from infection with mad cow disease — the ban on feeding rendered cattle meat or beef byproducts to cattle that was imposed by the Food and Drug Administration in 1997. That ban has been cited again and again by Agriculture Department and industry spokesmen as some sort of guarantee that mad cow has not taken hold in the United States. Unfortunately, this firewall may have gaps big enough to let a herd of steer wander through it.
First, the current ban still allows the feeding of cattle blood to young calves — a practice that Stanley Prusiner, who won the Nobel Prize in medicine for his work on the proteins that cause mad cow disease, calls "a really stupid idea." More important, the ban on feed has hardly been enforced. A 2001 study by the Government Accounting Office found that one-fifth of American feed and rendering companies that handle prohibited material had no systems in place to prevent the contamination of cattle feed. According to the report, more than a quarter of feed manufacturers in Colorado, one of the top beef-producing states, were not even aware of the F.D.A. measures to prevent mad cow disease, four years after their introduction.
A follow-up study by the accounting office in 2002 said that the F.D.A.'s "inspection database is so severely flawed" that "it should not be used to assess compliance" with the feed ban. Indeed, 14 years after Britain announced its ban on feeding cattle proteins to cattle, the Food and Drug Administration still did not have a complete listing of the American companies rendering cattle and manufacturing cattle feed.
The Washington State Holstein at the center of the current mad cow crisis may have been born in Canada, but even that possibility offers little assurance about the state of mad cow disease in the United States. Last year 1.7 million live cattle were imported from Canada — and almost a million more came from Mexico, a country whose agricultural ministry has been even slower than its American counterpart to impose strict safeguards against mad cow disease.
Last year the Agriculture Department tested only 20,000 cattle for bovine spongiform encephalopathy, out of the roughly 35 million slaughtered. Belgium, with a cattle population a small fraction of ours, tested about 20 times that number for the disease. Japan tests every cow and steer that people are going to eat.
Instead of testing American cattle, the government has heavily relied on work by the Harvard Center for Risk Analysis to determine how much of a threat mad cow disease poses to the United States. For the past week the Agriculture Department has emphasized the reassuring findings of these Harvard studies, but a closer examination of them is not comforting. Although thorough and well intended, they are based on computer models of how mad cow disease might spread. Their accuracy is dependent on their underlying assumptions. "Our model is not amenable to formal validation," says the Harvard group in its main report, "because there are no controlled experiments in which the introduction and consequences of B.S.E. introduction to a country has been monitored and measured."
Unfortunately, "formal validation" is exactly what we need. And the only way to get it is to begin widespread testing of American cattle for mad cow disease — with particular focus on dairy cattle, the animals at highest risk for the disease and whose meat provides most of the nation's fast food hamburgers.
In addition, we need to give the federal government mandatory recall powers, so that any contaminated or suspect meat can be swiftly removed from the market. As of now all meat recalls are voluntary and remarkably ineffective at getting bad meat off supermarket shelves. And most of all, we need to create an independent food safety agency whose sole responsibility is to protect the public health. Let the Agriculture Department continue to promote American meat worldwide — but empower a new agency to ensure that meat is safe to eat.
Yes, the threat to human health posed by mad cow remains uncertain. But testing American cattle for dangerous pathogens will increase the cost of beef by just pennies per pound. Failing to do so could impose a far higher price, both in dollars and in human suffering.
Eric Schlosser is author of "Fast Food Nation" and "Reefer Madness."