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MAD COW DISEASE

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Also known as Bovine Spongiform Encephalopathy (BSE) ... Agents that interfere with amyloid proteins interaction may be effective ... – PowerPoint PPT presentation

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Title: MAD COW DISEASE


1
MAD COW DISEASE
  • By
  • Nikki Graff
  • Ashley Smith
  • Heather Jennings

2
What is Mad Cow Disease?
  • Also known as Bovine Spongiform Encephalopathy
    (BSE).
  • It is a slowly progressive, degenerative
    neurological disease of adult cattle.
  • It is a fatal disease and affects the central
    nervous system.

3
Causes of Mad Cow Disease
  • Cause is unknown.
  • Scientists generally accept that the likely cause
    is infectious forms of a type of protein and
    prion that are initially found in animals.
  • Initial prions occur in small intestines and
    tonsils, and are found in central nervous system
    tissues.

4
Can this disease affect humans?
  • Humans cannot get Mad Cow Disease.
  • Humans can get a disease from exposure to the
    infected prion that is present in cows. This
    disease is a similar form of Mad Cow Disease
    called Variant Creutzfeldt-Jakob disease.
  • Nearly all cases of vCJD have been in the UK or
    have been in people with exposure to cattle meat
    products in the UK.
  • 153 cases of vCJD have been reported in the world
    since 1995.
  • 143 of these cases have been in the UK.

5
Causes of CJD
  • Eating infected beef
  • Genetic mutations
  • Random infection development
  • Infected surgery instruments
  • Tissue implants
  • Blood transfusion or blood products

6
Symptoms
  • Initial Symptoms
  • Insomnia
  • Depression
  • Confusion
  • Personality Behavioral Changes
  • Problems with memory, coordination, and sight.
  • After further development
  • Dementia
  • Involuntary/ Irregular Jerking Movements

7
Symptoms
  • Final Stages
  • Patient loses all mental and physical
    coordination
  • Lapses into a coma
  • Death

8
Origin
  • Hans Gerhard Creutzfeldt discovered the first
    case of a progressive mental and neurological
    disturbances in 1920
  • Alfons Maria Jakob discovered another three cases
    of defects in the motor system one year later.
  • Then in 1922 the eponym Creutzfeldt-Jakob
    disease was first used to describe a number of
    degenerative central nervous system diseases.
  • 30 years later a disease known as kuru was
    discovered in the Eastern Highlands of Papua New
    Guinea
  • caused from ingesting brain tissue of dead
    relatives for religious reasons.
  • There were major neuroplathological similarities
    between Kuru, CJD, and scrapie (a disease found
    to affect sheep).
  • 1960s the term transmissible spongiform
    encephalopathy was applied after the discovery of
    the transmissible ability of both Kuru and CJD
    diseases to chimpanzees.
  • Many years later, in 1980 there was an outbreak
    of the disease named bovine spongiform
    encephalopathy (BSE or mad cow disease).

9
Original Theories
  • First theory in describing the origin of mad cow
    diseases was developed by Daniel Carleton
    Gajdusek.
  • the disease was caused by slow viruses.
  • Today the theory in use is called protein-only
    hypothesis.
  • based on prions
  • Prions
  • Prions are used to designate a small pertinacious
    infectious particle that was resistant to
    inactivation by most of the procedures that
    modify nucleic acids, and to distinguish the
    agent from virus and viroids.
  • Prions are the only known infectious pathogens
    that are devoid of nucleic acid, all other
    infectious agents possess genomes composed of
    either RNA or DNA that direct the synthesis of
    their progeny.
  • Prion diseases may be manifest as infectious,
    genetic, and sporadic disorders.

10
Routes of Infection
  • acquired infection, which can be caused by diet
    and following medial procedures such as surgery
    or growth hormone injections.
  • apparent hereditary, which is caused by an
    autosomal and dominate trait.
  • Studies have shown a strong, but not absolute,
    correlation between specific PRNP mutations and
    different clinical forms of familial prion
    diseases.

11
Treatment
  • Anti-prion drugs
  • Agents that interfere with amyloid proteins
    interaction may be effective
  • goals of the treatments are to decrease the
    numbers of prions in the cells.
  • Recently a successful trial of injecting
    antibodies that latch onto prions into mice that
    were 30 days into the disease- before symptoms
    occur, but at a time when prions are multiplying
    ferociously.
  • animals stayed healthy for at least two years,
    rather than dying by the time they reached seven
    months.
  • These antibodies are capable of locking onto the
    prion proteins that cause brain-wasting mad cow
    disease, allowing early diagnosis and maybe even
    a vaccine
  • The deformed prion proteins, which cause the
    disease, carry a distinct genetic signature that
    antibodies can be trained to recognized

12
Control and Prevention
  • -Since 1989
  • The FDA other federal agencies have had ongoing
    regulatory measures in place to prevent BSE
    contamination of U.S. food and other products.
  • The USDA has prohibited the importation of live
    animals animal products from BSE-positive
    countries as well as other countries with the
    potential risk of BSE.

13
Cow Parts Banned
  • Parts of cattle at high risk for harboring the
    infectious agent for mad cow disease, include
  • Skull and brain
  • Small intestine
  • Eyes
  • Vertebral column
  • Spinal cord
  • Tonsils
  • Federal agencies protect public health by
    prohibiting these cow parts in the human food
    supply.

14
Control Policies in the US for BSE
  • Product Holding - FSIS inspectors no longer mark
    cattle tested for BSE as "inspected and passed"
    until confirmation is received by FSIS and the
    plant that the cattle have, in fact, tested
    negative for BSE.
  • Specified Risk Material Previous slide.
  • Advanced Meat Recovery - FSIS expanded a prior
    prohibition on spinal cord from being allowed in
    product produced from a technology called
    advanced meat recovery. This new regulation
    prohibits dorsal root ganglia, clusters of nerve
    cells connected to the spinal cord along the
    vertebral column, in addition to spinal cord
    tissue from being in AMR product.
  • Air-Injection Stunning - FSIS banned the practice
    of air-injection stunning to ensure that portions
    of the brain are not dislocated into the tissues
    of the carcass as a consequence of humanely
    stunning cattle during the slaughter process.

15
Economic strain Medications
  • In July of 1997, the European Union banned orally
    ingestible medicines that contain animal
    by-products.
  • Approximately 80 of these medications contained
    tallow or gelatinous material are made from
    cattle.
  • Overall effect of this ban could potentially lead
    to severe shortages of orally ingestible
    medications worldwide.
  • FDA is trying to convince the European Union to
    postpone on the ban at least until drug
    manufacturers are able to find safe animal
    substitutes.
  • Finding new materials and gaining approval from
    the FDA is a long process.
  • For the US pharmaceutical industry alone, four
    billion dollars is at stake in annual exports.

16
Economic Impact
  • The BSE announcement immediately triggered bans
    on US beef exports across the globe and sent US
    cattle and beef prices tumbling.
  • Retail and wholesale beef prices dropped between
    5 and 10 after the announcement.
  • Revenue losses to the cattle industry reached up
    to 2 billion in the first quarter of 2004.
  • Cattle prices fell between 15 and 20.
  • The Kansas City Federal Reserve District lost
    850 million. (This district accounts for 43 of
    the US cattle industry)

17
Impact on consumers
  • Research has shown that food safety concerns
    create only short- run impacts on consumption.
    After this initial reaction to BSE, people tended
    to forget and return to their eating habits.
  • Wholesale beef companies, fast food restaurants,
    and similar beef industry participants have
    reported no measurable fall in the US beef
    consumption.
  • National Cattlemens Beef Association reported
    that 89 of consumers expressed confidence in the
    safety of US beef after the BSE incident,
    compared to 58 in September 2003.

18
Change in Beef Consumption
  • Nearly 19.5 percent of those who knew about the
    case say they have since reduced their beef
    consumption.
  • 9 say they eat somewhat less beef
  • 5 say they eat much less
  • 5 say they have stopped eating beef altogether.
  • 4 of the total population claims to have stopped
    eating beef.
  • The majority, over 75, say that have not changed
    their beef consumption.

19
Things to Remember
  • BSE is always fatal.
  • BSE can be tansfered thoughout species
  • BSE efffects the brain
  • BSE has had a huge economic strain on the world.

20
The END
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