Transcript Chronic Wasting Disease

Chronic Wasting
Disease (CWD)
David Litts
What is it?
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Prions (infectious incomplete protein)
Creutzfeldt-jakob disease – humans
Transmittable spongiform
encephalopathy (TSE)
Transmittable and infectious to
members of effected species
Breaks down brain tissue
CWD history
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Known to only effect 3 Cervidae
species
Effects on other Cervidae species is
unknown (cattle resistant)
Speculation CWD stems from sheep
“scrapie”
CWD history
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Spontaneous TSE in deer
Known in mule deer for over 40 years
Spreading across the USA quickly
CWD diagnosed in elk sent to Korea
from Canada
Clinical Signs
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Change of behavior
Head tremors
Excessive drinking and urination
Reduced eating
Walking repetitive path
Pneumonia is commonly found in
antemortem testing
Clinical Signs
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Loss of body
condition
Drooling
Wide base stance
Facts on CWD
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Effects adults 17 months to 15+ years
– Most 3-5 years old, or >15 years
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Both sexes
No seasonality
Clinical duration->1 year usually
months ending in death
17 month minimum incubation period
Areas found
How to diagnose
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Sample a certain brain area
Test sample for BSE (Bovine spongiform
encephalopathy)
Control strategies
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No treatment is available
Inevitable fatality
No vaccines available
Quarantine
Depopulation
Harder to control in free-range animals
Free-range control
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Selective culling of clinical suspects
Localized population reduction in areas
of high concentration
Tonsil biopsy as an antemortem test
for CWD
What to do
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Contact wildlife management officials
– Pennsylvania Game Commission
– US Fish and Wildlife Service
A PA threat?
What do you think?