Bovine Spongiform Encephalopathy: - PowerPoint PPT Presentation


PPT – Bovine Spongiform Encephalopathy: PowerPoint presentation | free to view - id: 2682e-YWU3N


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation

Bovine Spongiform Encephalopathy:


Public has permission to use the Material herein, but only if author(s), course, ... Mad Cow: ... – PowerPoint PPT presentation

Number of Views:920
Avg rating:3.0/5.0
Slides: 51
Provided by: tri574


Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Bovine Spongiform Encephalopathy:

Bovine Spongiform Encephalopathy Mad Cow
  • Melody ODonnell
  • URBS 515 Race Poverty and the Environment
  • Professor Raquel Pinderhughes
  • Urban Studies Environmental Studies Programs
  • San Francisco State University
  • Spring 2004
  • Public has permission to use the Material herein,
    but only if author(s), course, university and
    professor are credited.

This presentation focuses on the history and
impacts of Bovine Spongiform Encephalopathy (BSE).
  • It is designed to inform the public about the
    danger of this disregarded disease in the United
  • It analyzes and describes the origins and
    transmission of this disease, paying particular
    attention to the social, environmental and public
    health impacts associated with BSE.
  • We start by analyzing the rendering process that
    is thought to be a major factor in transmission
    of this disease. We then look at a brief history
    of its effect on humans and other animals. This
    is followed by a comparison of the safeguards
    taken by the U.S. compared to other countries.
  • We conclude with proposals to protect those who
    consume beef products from the United States.

  • Why is it important for us as Americans to know
    about a disease that is thought to be a problem
    only in Europe, and more recently, in Canada?
  • Almost 77 million Americans eat beef every day. 1
  • If the research is true that humans are
    susceptible to the human form of Spongiform
    Encephalopathy, and this disease is in fact
    transmissible from consuming infected beef
    products, why isnt more being done to protect
    the American public?

  • BSE can be transmitted from mother to fetus, as
    well as from bull sperm to the female.
  • Also contracted when infectious agent (prion) is
    ingested in food.
  • Adult cows are fed rendered animal protein to aid
    in bulking up.
  • Calves are fed a baby formula made from bovine
    blood because it it much less expensive than
    milk, not to mention the comparative resale
    values of the two liquids.

Protein Concentrates rendered animal protein
  • This inexpensive, high protein food is sold as
    granules or dry food pellets to animal farmers
    for vigorous animal growth.
  • It is sold in greatest quantities to cattle
    farmers because administration of hormones such
    as RGBH to their cows for increased milk
    production requires them to increase the cows
    protein consumption.
  • This feed is also given to
  • Pigs
  • Turkeys, chicken and ducks
  • Horses
  • Catfish, salmon and shrimp
  • Domestic animals (cats and dogs)
  • Zoo animals

Rendered Protein Ingredients
  • Animals unfit for human consumption such as
  • Sick cows
  • Sick pigs
  • Sick turkeys, chicken and ducks
  • Horses
  • Sick catfish, salmon and shrimp
  • Cats and dogs
  • Zoo animals
  • Road kill

More ingredients
  • Frying oil from restaurants
  • Brains, spinal cords, feathers, hooves, skins,
    hair, fur, whiskers, bones, teeth, etc. remaining
    from slaughterhouses
  • Sewage sludge
  • Manure
  • Sawdust/wood scraps
  • Newspaper
  • Cement dust
  • Maggot infested grains

Rendering Process Health and Environmental
  • The animals and other ingredients are processed
    into smaller pieces in a Double Screw Press
    (top left) and then boiled down in huge vats
    (bottom left) at extremely high temperatures with
    dangerous chemicals. Infected tissue from a
    single animal has the potential to mingle with
    tissues from thousands of others, and then be
    distributed widely in feed.1

Worker Hazardous Exposures
  • Dangerous chemicals such as hydrogen sulfate,
    potassium permanganate, chlorine gas, sodium
    hypochlorite, lime, formaldehyde, lye, acetic
    acid and phosphoric acid.
  • Extreme Heat
  • When heat of process was lowered in response to
    worker safety issues, process does not
    sufficiently remove contaminants Salmonella, E.
    coli, infectious prions pesticides,
    pharmaceuticals and hormones. These contaminants
    not only pose a problem for the animals ingesting
    the food but also for the workers handling the
  • Aerosolized fat mist that sprays out of the vats
    coats the walls and floor of the plant, making
    all surrounding surfaces very slippery and
    creating an extreme fire danger.

  • The rendering industry defends their work as a
    form of recycling-
  • 1.3 million tons in the U.K. in 19881
  • 15 million tons in the U.S. in 19922
  • This is waste that would have otherwise gone into
    landfill. But is the risk belong taken worth the

Not only is this rendered protein used in the
food we feed our pets and food animals, it is in
the products we use everyday. The fat is skimmed
off of the top of the vat during the rendering
process and used to make marshmallows and cereal
bars, lipstick and hand lotion and garden
fertilizers, tires and yogurt and breath mints.
Therefore, not only have we turned herbivore cows
into not just carnivores but cannibals, we have
put ourselves and other animals at risk . The old
adage you are what you eat has never been more
true-not only are we the food that we eat, we are
also what our food consumes. Humans, being at the
top of the food chain, are consuming all of the
toxins, chemicals, hormones and diseases that
affected our food before we consumed them.
Symptoms of Bovine Spongiform Encephalopathy
  • restlessness
  • aggressiveness
  • loss of motor function
  • loss of appetite
  • convulsions
  • blindness
  • self mutilation

the initial discoveries of BSE
  • In April of 1985, the first identified case of
    BSE was initially believed to be grass
    staggers, a common illness caused by Magnesium
    deficiency. The cow was observed as seeming to
    hallucinate.1 Given an Unknown diagnosis, as a
    possible brain tumor or lead poisoning. The brain
    autopsy revealed spongiform patterns.
  • On March 20, 1996 the UK Department of Health
    announced that BSE was in fact transmissible to
  • The announcement was so devastating to the UK
    cattle economy that many ranchers were forced
    into bankruptcy beacuse of the immediate loss of
    entire herds of potentially contaminated cattle,
    as well as the immediate consumer boycott of beef
    and beef products. This downturn was so terrible
    in fact that there was an epidemic of suicides
    within the ranching community.2
  • School districts began banning beef in school
    lunches and vegetarianism rose in popularity for
    the general public in the UK.
  • In June, 1987 John Wilesmith, a veterinarian
    epidemiologist for the Ministry of Agriculture,
    Fishers and Food (MAFF) made the link between
    BSE and cattle feed made from scrapie infected

  • On July 7, 1988, a settlement was offered by
    British Agriculture of payment for 50 of the
    worth of the cow if reported to the government.
  • This in fact gave the ranchers an incentive not
    to report suspicious cases, as they would make
    the full profit from sneaking past inspection and
    selling the meat into the market versus reporting
    the problem and only receiving 50 compensation.
  • Not only did ranches lose money from BSE reports,
    they lost credibility as well as their customer
    base, and in effect became blacklisted.

The effect of BSE in the E.U.
  • Millions of suspect animals in the UK and
    across Europe have been destroyed since 1986, but
    the disease is still very much present.

Causative agent of BSE What is a Prion?
  • Identified by Dr. Stanley Prusiner, who in 1997
    won the Nobel Prize for his research on prions.
  • Does not contain RNA or DNA (therefore not
    technically alive like other infectious agents
    like viruses or bacteria)
  • Does not evoke any detectable immune response or
    inflammatory reaction in host animals.
  • In most animals, 3-7 years dormant incubation
    where the animal is asymptomatic.
  • Average age of cows in the U.S. is 4 years old,
    meaning that the animal may be infected but still
    asymptomatic at time of slaughter.

Prions in the body
Found in mainly in the brain, spinal cord and
nervous tissue, with increasing research
discovering prions in glands and blood as well.
  • Physical Attributes of the affected brain
  • Enlarged astrocytes- Star shaped cells attached
    to blood vessels in brain.
  • Holes where neurons used to be.
  • Amyloid Plaques-flower shaped protein waxy

BSE Brain
Scrapie Brain
  • Prion protein is indestructible
  • by heat up to 1000 F (350 C)
  • Hot enough to melt lead.
  • In 1986, 4.5 million cows were incinerated in the
    U.K. after the discovery of BSE. The ashes,
    stored in underground concrete containers, were
    retested again in 1998 and found to still be
    infected with active prions.

So how do these prions affect humans?
Kuru Creutzfeldt-Jakob Disease (CJD) New Variant
Creutzfeldt-Jakob Disease (vCJD)
  • Cannibal culture of Papua New Guinea.
  • Affected mostly women and children, with a small
    amount of men. anywhere from 5 to 10 percent of
    the population died each year from kuru.1
  • When loved one died, men ate muscle portions and
    women and children were left with the lesser
    organs and brain, where we now know prions tend
    to cluster.
  • The rare male cases occurred because of the
    possible 20 to 30 year dormancy period of prions
    where the infectious agents were ingested as

Kuru (continued)
  • Analyzed by New Yorker Carleton Gajdusek and
    Lithuanian Dr. Vincent Zigas (both in photo) in
  • Initially believed to be a virus causing
    encephalitis (swelling of the brain), with the
    same symptoms as Parkinson's, Alzheimer's, and
    MS. However these were degenerative, not
    infectious diseases, and not epidemic as kuru
  • After autopsy, Gajdusek made the connection of
    brain damage to recently discovered CJD.
  • No treatment was ever found, and when cannibalism
    was eventually phased out of the culture, so too
    came the disappearance of kuru.

Creutzfeldt-Jakob Disease (CJD)
  • Discovered in 1921by Dr. Hans Gerhard Creutzfeldt
    and Dr. Alfons Jakob, colleagues at the
    University of Hamburg Germany.
  • Now more common that rabies.
  • Physical attributes of the affected brain
  • Enlarged astrocytes- Star shaped cells attached
    to blood vessels in brain.
  • Holes where neurons used to be.
  • Amyloid Plaques-flower shaped protein waxy

Microscope slide of brain affected by CJD
CJD Symptoms
  • (first 7 same as BSE)
  • restlessness.
  • aggressiveness (biting and hitting).
  • loss of motor function.
  • loss of appetite.
  • convulsions.
  • blindness.
  • self mutilation.
  • inability to swallow.
  • 90 of deaths usually occur within one year of
    diagnosis, difficult to confirm diagnosis until
    post mortem.

CJD Transmission
  • Humans can acquire the prion by exposure to meat
    that has come in contact with the brain or spinal
    column of the animal.
  • Surgical equipment can be unknowingly infected by
    use on a patient with CJD, and because
    sterilization techniques do not kill the prion,
    the are transmitted to the other patients in
    subsequent procedures.

In common slaughtering practices, the animal is
often sliced at least once through the torso,
severing the spinal column and exposing all the
the surrounding flesh to the infectious agent.
  • Similarity to Alzheimers disease
  • very similar patterns of dementia.
  • because of late onset of CJD, both usually occur
    later in life.
  • CJD often misdiagnosed as the more common
    Alzheimers, as only way to differentiate is post
    mortem brain autopsy (which most families do not
    agree to.)
  • However, a 1989 article in the journal Neurology
    explains that autopsies of 54 dementia patients
    at the Veterans Medical Center in Pittsburgh, PA
    revealed that 3 of the had actually died of CJD.
    Given this figure we can infer than as many as 5
    of Alzheimers patients are actually suffering
    from CJD.
  • In Georgia, according to state law, autopsies
    cannot be performed on suspected CJD cases
    because the equipment cannot be sterilized.
  • As with all TSEs there is no cure or proven

New Variant CJD (vCJD)
  • Much earlier onset but same symptoms as classic
    CJD, often with prolonged life expectancy.
  • A recent test on surgical equipment used for
    tonsillectomies in the U.K. revealed that 50 of
    tools were infected with vCJD, even after
    sterilization and autoclaving. (The tonsils are
    one of the major glands where the body stores

Jonathan was diagnosed with vCJD at 17 and
treated with the drug Pentosan polysulphate (PPS)
, commonly used as an arthritis treatment for
dogs. This extended his life by several years,
but did not cure him.
Other Forms of Transmissible Spongiform
  • Known to have existed for at least 200 years
    without being transmitted to humans, while being
    endemic in sheep populations all over the world.
  • There are 23 variations of prion mutation
    possible, each with a different incubation period
    as well as patterns of amyloid plaque in the
  • Each variation is known by a unique symptom, such
    as drowsy, hyper, or fat building.

Domestic and Exotic Felines
  • The first case of domestic Feline Spongiform
    Encephalopathy was discovered in the U.K. in May
    of 1990. Max was a 5 year old Siamese cat. The
    FSE was discovered in a rare autopsy (which are
    thought to be too costly and unnecessary by most
    pet guardians).
  • Lab tested cats are not susceptible to scrapie
    but extremely susceptible to BSE. These results
    reinforced the findings that it was possible for
    a species (such as humans) to be susceptible to
    BSE without being susceptible to scrapie, despite
    their overwhelming similarities.

A Puma and 3 cheetahs died from FSE in 1989 at
the London Zoo from rendered food.
Other Zoo Animals
Arabian Oryx
From 1986 to 1989. The London Zoo lost several
varieties of hoofed ruminants (cud chewing
animals), including Nyala, Gemsbok, Kudu, Eland
and Arabian Oryx, (all similar to antelope or
deer), to spongiform encephalopathy. These
animals had all been fed rendered protein.
  • Wisconsin is the largest U.S. producer of mink.
  • Known as sentinel species, mink often show
    disease before other animals because they are fed
    stock animals unfit for human consumption from
    slaughterhouses and farms.
  • Contract many bovine diseases- anthrax, botulism,
  • Outbreaks of MSE common, devastating to ranchers.
    a single outbreak could wipe out all of the
    animals on an entire mink ranch.1 100 fatal to
    mink exposed to contaminated feed.
  • Isolated prion from autopsy indistinguishable
    from scrapie.

Ranched for their fur, these carnivorous animals
are extremely susceptible to Mink Spongiform
Encephalopathy from eating other infected animals.
Chronic Wasting Disease (Deer and Elk)
  • Chronic Wasting Disease is the spongiform
    encephalopathy most similar to scrapie.
  • The infected animals exhibit more progressive
    degeneration (similar to Alzheimer's) than other
  • Most likely not contracted by ingesting infected
    proteins, but through everyday contact with other
    infected animals in their herds.

Lab Tests
  • In laboratory tests, animals were injected with
    active prions from cows infected with BSE.
  • The infectious agent was not ingested in food as
    most animals and humans would be exposed to the
    prions. Even so, all of the test subjects
    contracted some form of prion disease.
  • monkeys
  • sheep (different variation of scrapie contracted)
  • goats
  • mice/ rats
  • pigs

But weve only had one confirmed case of mad cow
disease in the U.S. ! How can we blame BSE for
all of these other spongiform encephalopathies
occurring in the U.S., especially vCJD?
The Cow that Stole Christmas.
  • On December 23, 2003, the first confirmed case of
    BSE was reported on a family farm in Moses Lake,
    Washington .
  • Initially described by federal officials as a
    downer cow the family later came out that the
    cow was in fact ambulatory, and that the test was
    run not because the animal was sick but because
    the family farm has a special contract with the
    government to collect brain samples from up to
    1000 animals for mad cow testing, no matter what
    their physical condition. 1
  • Since the animal was healthy, the program that
    was begun after this discovery by the USDA does
    not fully address the problem, as it only allows
    random testing on Downer Cows.

The U.S. Beef Market At Home
  • US local beef market not significantly hurt by
    discovery of BSE.
  • There was a slight decline in U.S. sales in
    January and February of 2004. However, in many
    places sales of beef, both at retail and
    wholesale dealers, are reported to have increased
    from the previous years due to consumer trust in
    government protection.1

The U.S. Beef Market International Exports
  • Beef is The United States 1 export
  • 4.3-billion annually
  • Any damage to this international economy would
    have widespread impacts across the country.
  • Because more than 30 nations have now banned beef
    from the United States, Many packing plants are
    laying off workers and feedlots left with
    thousands of unsold animals. Those that do sell
    are at such a low price that some feeders
    feel... lucky if the broke even on each animal
    sold.1 Sales of approximately 9.6 percent of
    total U.S. production, or 3.1 billion pounds of
    beef will be lost if confidence is not regained.

Government officials have placed concerns for
the food industry over human health and welfare.
  • Does this result in a lack of regulation?
  • In the U.S. more than 1.8 million cattle collapse
    before slaughter yet are still seen as fit for
    consumption. About 100, 000 of these die
    mysteriously of what is known as Downer Cow
    Syndrome but are not tested and are still
    consumed by humans.2
  • only one out of every 18, 000 cows slaughtered
    for human consumption are tested for BSE in the
    United States. (.000055)
  • The USDA must authorize every test. When a cattle
    farmer proposed to voluntarily test every cow,
    their request was denied and the practice was
    forbidden across the country. 3

What information do these countries have that is
being kept from the American public? Do Americans
not deserve the same protection given citizens
all over the industrialized world?
  • Its unlikely the single Holstein discovered
    in Washington state is the only sick animal ever
    imported into the country from Canada, and
    possibly Europe... Since none of the other
    animals was (sic) detected, their infected
    tissues were almost certainly processed into
    cattle feed years ago, spreading and amplifying
    the disease so that cattle in the U.S.A. have
    also been indigenously infected.- USDA Report
    submitted to Ann Veneman, Secretary of

So why do we continue with these dangerous
  • In an effort to contain the problem, in addition
    to testing, many public interest groups have
    proposed banning feeding animal protein to
  • 1997 USDA advisory barring ruminant (cud
    chewing animal) protein from cattle feed seen as
    more as a suggestion than enforceable. (It is
    still legal to feed to all other animals,
  • The Vice President of the American Feed Industry
    Association, Richard Sellers estimates loss of
    100 million annually if a ban was imposed on
    feeding animal protein to cattle.1

Who is more important to the U.S. government,
their people or their businesses?
  • The American public trusts the Federal
    government to protect us, as a parent would
    protect their children. As our parent, would they
    take the risk of feeding us something that they
    know has a very good chance of making us sick?
  • No parent would ever willingly put their child in
  • So too should the USDA, FDA, CDC and DHHS care
    for us.

Recommendations to USDA and FDA to more
adequately protect consumers
  • (Compiled from suggestions by Physicians
    Committee For Responsible Medicine, Public
    Citizen and the World Health Organization)

  • Restrict marketing of downer cows for any
    purpose, whether for animal or human feed.
  • Create strict regulations for cattle feed that
    match those of the E.U. nations and Japan. We
    need to remember that cows are not meant to eat
    cows or other animals. Sue Jarrett, Colorado
    rancher. 1
  • Properly train and equip field personnel to test
    and report possible cases in a timely and
    effective manner.
  • Properly label potentially contaminated food,
    (including those product with animal byproducts
    such as gelatin or natural flavorings) with
    stickers similar to salmonella warnings on
    chicken and Surgeon General warnings on tobacco
  • Prohibit the use of animal byproducts in
    cosmetics and medications.
  • Increase communication within regulating agencies
    to expedite action if necessary. Research is
    performed by National Institutes of Health (NIH),
    Protection primarily the issue of the FDA, Human
    disease surveyed by the Center for Disease
    Control (CDC) and all of these agencies are
    overseen by the Department of Health and Human
    Services (DHHS). Better communication will mean
    faster response times.

If you dont look for it, youre not going to
find it - Howard Lyman, former Montana
cattle rancher.
  • Animal and Plant Health Inspection Service
  • Program Aid No. 1705 Bovine Spongiform
    Encephalopathy An Overview. October, 2001
  • Veterinary Services February 2002 Bovine
    Spongiform Encephalopathy Fact sheet
  • Bovine Spongiform Encephalopathy (BSE) Response
    Plan Summary
  • Barone, John. U.S. mad cow discovery lowers
    int'l. beef exports, prices. Nation's Restaurant
    News, February 2,2004, Vol. 38 Issue 5, p36.
  • BBC News
  • BSE Experts say Old Meat Is Safe February 4
  • vCJD and BSE - the link October 20, 2000
  • CJD Drug Hope September 25, 2003
  • The Caledonian Cat Clinic http//
  • Center For Disease Control (CDC)
  • Doughton, Sandi and Scott, Alwyn. Experts
    predict more U.S. cases of mad cow. Seattle
    Times Thursday, February 05, 2004
  • Department of Agriculture-Office of the Secretary

  • McNeil, Donald G. Jr. U.S. Won't Let Company
    Test All Its Cattle for Mad Cow. New York Times
    April 10, 2004
  • Morris, Chris. Research raises new human-BSE
    fears Canoe News (Canada) http//
  • Mother Earth News (Green Gazette) Mad Cow
    Disease Hits Home. April/May 2004
  • Murphy, Richard McGill.. Truth or Scare What
    Food Producers Need to Know About Americans
    Demands for details on what they buy to eat.
    American Demographics, March 2004.
  • Muzzi, Doreen, BSE Still influencing Cattle
    Market Southeast Farm Press March 3, 2004
  • Nobel Prize e-museum http//
  • Organic Consumers Association
  • Ortiz, Jon. California Lawmakers Push to End
    Secrecy over Meat Recalls. Sacramento Bee April
    1, 2004
  • People for The Ethical Treatment of Animals
    (PeTA) http//
  • Physicians Committee For Responsible Medicine
    (PCRM) press release Mad Cow Disease February
    11 2004

Image Bibliography
  • arabian oryx http//
  • baby http//
  • beef product flow chart
  • BioHazard http//
  • Carleton Gajdusek http//
  • cjd brain
  • cowpilehttp//
  • cow tounge http//
  • elk http//
  • Farside comics http//
  • feedbags http//
  • gemsbok http//
  • Johnathan http//
  • kuru http//
  • lab rat http//
  • lipstick
  • lotion http//
  • Mad Cow http//

On a lighter note