Scrapie is a fatal, neurological disease that affects sheep and goats. It is caused by prions, which are misfolded proteins, and results in the accumulation of prions in the nervous system, leading to neuronal death. Symptoms include weight loss, behavioral changes, and tremors. It is transmitted from infected females to offspring at birth or through contact with birth materials. There is no treatment for scrapie. Control methods focus on selective breeding of resistant sheep genotypes and restricting the spread of infected tissues and milk.

1. SCRAPIE
D.INDRAJA

2. • Scrapie is a fatal, degenerative disease affecting the nervous
systems of sheep and goats
• It is a chronological disease
• The causative agent is due to the misfolding of protein about 20-30mm
long
• Resistant to formaldehyde & high temperature(80oc)
• The name scrapie is derived from one of the clinical signs of the
condition, wherein affected animals will compulsively scrape off their
fleeces against rocks, trees or fences. The disease apparently causes an
itching sensation in the animals.
• Scrapie has been known since at least 1732 and does not appear to be
transmissible to humans.
• Scrapie usually affects sheep around three to five years of age

3. Cause
• It is a meber of transmissable spongifoem encephalopathies a group of
fatal neuro degenerative disease caused by prions
• The agent is thought to be much smaller than the smallest currently
known virus and the prevailing theory is that it is caused by a misfolded
protein called a prion.
• Prions multiply by causing normally folded proteins of the same type to
take on their abnormal shape, which then go on to do the same, in a
kind of chain reaction.
• These abnormal proteins are gradually accumulated in the body,
especially in nerve cells, which subsequently die.

4. Geographical distribution
• Classical scrapie  By transmission
• seen in almost all major continents last reported places were
new Zealand, Australia
• Atypical scrapie  recently recognized which is different from normal
classical scrapie in its neuropathological and biochemical features
• It has been detected in European countries, North america, Newzealand,
Australia, it is almost seen in where ruminants are found

5. Symptoms
Weight loss
Behavioral abnormalities
Biting at legs or sides
Motor abnormalities
Bunny hop moment of rear legs
Tremor
Head pressing
Wool pulling
Lip smacking
Blindness
Stargazing

6. TRANSMISSION OF SCRAPIE
•Scrapie agent is spread most commonly from infected female to
her offspring at birth (via placenta and placental fluids), or to
other animals exposed to birth environment.
•The risk of transmitting scrapie via embryos and semen is
negligible.
•The scrapie agent has been experimentally transmitted through
the milk.
•The scrapie agent persists in soil.
•Only sheep with certain genotypes will develop scrapie if they
are exposed to the infective agent.
•Resistant genotypes haven’t been identified in goats yet.

7. Detection techniques
Western blotting
ELISA
Treatment
• There is no treatment for scrapie or any other prion disease
Control measures
• It is prevented by not feeding the tissue of infected animals
• Not feeding the infected milk to young ones
• Resistant sheeps are used for breeding
• Eradication of the animals which are infected

8. Creutz feldt Jakob disese
D.INDRAJA

9. • Creutzfeldt–Jakob disease (CJD), also known as subacute
spongiform encephalopathy or neurocognitive disorder due to prion
disease, is a fatal degenerative brain disorder
• CJD is caused by a protein known as a prion.[5] Infectious prions
are misfolded proteins that can cause normally folded proteins to
become misfolded
• It is a very rare fatal neurodenerative syndrome that causes 1 in million
• Depending on the reason of appearance it is categorized in to different
types they are
• Sporadic CJD  appears even though there are no risk factors
• Heriditary CJD  from family members
• Aquired CJD  exposure to brain through medical procedures or eating
meat of containg infected prions

10. Causes
• CJD is a type of transmissible spongiform encephalopathy (TSE), which are caused
by prions.
• Prions are misfolded proteins that occur in the neurons of the central nervous system
(CNS). They are thought to affect signaling processes, damaging neurons and resulting
in degeneration that causes the spongiform appearance in the affected brain.
• The CJD prion is dangerous because it promotes refolding of native prion protein into
the diseased state.The number of misfolded protein molecules will
increase exponentially and the process leads to a large quantity of insoluble protein in
affected cells.
• This mass of misfolded proteins disrupts neuronal cell function and causes cell death.
• Mutations in the gene for the prion protein can cause a misfolding of the dominantly
alpha helical regions into beta pleated sheets.
• Once the prion is transmitted, the defective proteins invade the brain and induce other
prion protein molecules to misfold in a self-sustaining feedback loop.
• These neurodegenerative diseases are commonly called prion diseases

11. Symptoms
Dementia
Initially with muscle coordination problems
Personality changes(impaired memory,judgement,thinking)
Impaired vision
Insomnia
Depression
Unusual sensation
As increasing the condition they may go blind, loss of ability to move
and speak and finally to coma
Pneumonia and other infections often occur and can lead to death

12. Transmission
Can not be transmitted by air or direct contact
When exposed to brain tissue/ Spinal cord fluid from infected person
transmission is done
Can be transmitted by graft of dura matter
From surgical instruments that are treated with infectious patients(that
are not sterilized)
Many people are also thought there is transmission via blood there are
no evident
Diagnosis
EEG(electroencephalography)  it visualizes brain electrical pattern
 Cerebrospinal fluid test (RT QUIC) Real time-quaking induced
conversion (which detects prions in CSF(cerebro spinal fluid)

13. Treatment
• There is no cure or effective treatment for CJD.
• Some of the symptoms like twitching can be managed, but otherwise
treatment is palliative care.
• Psychiatric symptoms like anxiety and depression can be treated with
sedatives and antidepressants.
• Myoclonic jerks can be handled with clonazepam or sodium valproate.
• Opiates can help in pain.
Preventing
• Not donating blood, tissues or organs if they have suspected of having
CJD
• Cover cuts and abrasions with water proof dressing
• Wearing gloves when handling with persons tissue and fluids or
dressing any wound

14. • In treatment use disposable bed clothes, if not the clothes are kept in undiluted
chlorine beach for an one hour
• Face protection is used when treating there is a risk of splasing contaminated
blood or CSF
• Soak instruments in undiluted chlorine for one hour and use autoclave to sterilize
it

15. This Photo by Unknown Author is licensed under CC BY-NC