MAD COW DISEASE

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MAD COW DISEASE

• By
• Nikki Graff
• Ashley Smith
• Heather Jennings

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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.

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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.

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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.

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Causes of CJD

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

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Symptoms

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

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Symptoms

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

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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).

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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.

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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.

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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

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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.

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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.

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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.

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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.

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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)

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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.

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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.

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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.

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The END