Rose Sydlowski

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Rose Sydlowski Nicole Sheimo
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What is CWD?

• Transmissible spongiform encephalopathy
• Occurs in white-tail deer, mule deer, and elk
• 100 fatal

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TSEs

• Prions infectious proteins (probably)
• Abnormal form of a normal cell protein found in
  CNS and lymphoid tissues
• Self-replicating causes conformational change
  in normal proteins, converting them to prions
• Neurodegenerative spongiform change in
  cerebrum, neuronal degeneration, accumulation of
  abnormal protein

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Other TSEs

• Scrapie 1st reported mid-1700s, never found in
  other species
• BSE 1st case probably occurred 1985, only TSE
  known to affect both humans and animals
• CJD human TSE, vCJD human mad cow
• Transmissible mink encephalopathy

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Clinical Signs of CWD

• Adult animal
• Decreased appetite
• Poor body condition
• Tremors, stumbling, ataxia
• Difficulty swallowing
• Increased thirst, PU
• Excessive salivation, drooling

• Incubation months to years
• Signs persist days to months (up to 1 yr)

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Transmission

• Not fully understood, may be
• lateral transmission
• urine, feces, saliva
• Increased population density
• Captivity (contact with wild)
• Feeding

• VERY resistant in environment

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Diagnosis

• Histopathology? Spongiform lesions in brain
• Immunohistochemistry? detects CWD protein in
  brain and lymphoid tissue

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Diagnosis
IHC parasympathetic nucleus in obex
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Diagnosis

• IHC on brainstem neurons
• CWD protein stains darkly

• Vacuolization of neurons

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• CWD has been known to exist
• since 1967
• mule deer in Colorado

• Small endemic area recognized
• in wild herds
• Northeast Colorado
• Southeast Wyoming
• Southwest Nebraska

?Why do we care about it now??
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ITS EPI TIME!!!

• CWD is spreading
• New areas of CO and NE
• Has since been found (wild or captive) in SD, KS,
  OK, MT, MN, NM, and.
• WISCONSIN!!
• (White-tail, 2002)

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EPI TIME

• Prevalence
• Wild herds limited data
• lt 1-15 mule deer
• lt 1 elk

• Captive herds higher prevalence
• 23-90, depending on herd

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Control

• Challenging
• No treatment
• No vaccine
• Long incubation period
• No reliable antemortem test
• Persistent in environment
• Transmission ?

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Control

• Captive herds
• Depopulate or quarantine
• Environmental contamination?
• Wild herds
• Surveillance
• Containment, eradicate?
• Limit movement of animals
• Ban supplemental feeding
• Population reduction (?)

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What about Michigan?

• Discovery of CWD in Wisconsin? threat to
  Michigan!
• Goal Keep CWD out!!!
• 1.8 million wild deer and elk
• 900-1000 privately-owned facilities (25000
  animals)

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What about Michigan?

• If introduced into MI, CWD would negatively
  impact
• Animal health wild and captive
• Economics
• Quarantines and restrictions on MI cervids
• Public health fears-- hunting

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Michigans Plan

• Importation of cervids Banned
• Supplemental feeding Banned in UP (and LP)
• Increased surveillance
• Education Hunters, Farmers, Residents
• Response Plan plans for containment and
  eradication

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Surveillance

• MI was conducting surveillance before CWD found
  in WI
• 1998 DNR tested 459 deer from NE LP, all (-)
• Targeted surveillance tested deer with
  suspicious symptoms, all (-)

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Surveillance

• DNR and MDA New plans include targeted and
  active testing
• 6000 wild deer over the next 3 years
• 50 deer per county
• 50 elk per year
• Additional testing of captive cervids

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Surveillance

• IHC testing of tissues will be performed by the
  Diagnostic Center

for Population and Animal Health
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Transmissible to people?
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Suggestions for Hunters

• No evidence that people can contract CWD by
  eating infected animals
• CDC risk is extremely small, if it exists at
  all
• In CWD areas very low of animals are infected

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Suggestions for Hunters

• Dont consume meat from infected or ill animals
• Dont consume nervous system or lymphatic
  tissues minimize contact
• Wear gloves when field dressing, wash hands
• Bone out meat
• Have head tested

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References
CWD Alliance www.cwd-info.org Michigan
DNR www.michigan.gov/dnr Minnesota
DNR www.dnr.state.mn.us/mammals/deer/cwd.html Dr
. Matti Kiupel And special thanks to our model,
Kevin Kristick!
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Questions?