Chronic Wasting Disease (CWD) David Litts

What is it? Prions (infectious incomplete protein) Prions (infectious incomplete protein) Creutzfeldt-jakob disease – humans Creutzfeldt-jakob disease – humans Transmittable spongiform encephalopathy (TSE) Transmittable spongiform encephalopathy (TSE) Transmittable and infectious to members of effected species Transmittable and infectious to members of effected species Breaks down brain tissue Breaks down brain tissue

CWD history Known to only effect 3 Cervidae species Known to only effect 3 Cervidae species Effects on other Cervidae species is unknown (cattle resistant) Effects on other Cervidae species is unknown (cattle resistant) Speculation CWD stems from sheep “scrapie” Speculation CWD stems from sheep “scrapie”

CWD history Spontaneous TSE in deer Spontaneous TSE in deer Known in mule deer for over 40 years Known in mule deer for over 40 years Spreading across the USA quickly Spreading across the USA quickly CWD diagnosed in elk sent to Korea from Canada CWD diagnosed in elk sent to Korea from Canada

Clinical Signs Change of behavior Change of behavior Head tremors Head tremors Excessive drinking and urination Excessive drinking and urination Reduced eating Reduced eating Walking repetitive path Walking repetitive path Pneumonia is commonly found in antemortem testing Pneumonia is commonly found in antemortem testing

Clinical Signs Loss of body condition Loss of body condition Drooling Drooling Wide base stance Wide base stance

Facts on CWD Effects adults 17 months to 15+ years Effects adults 17 months to 15+ years –Most 3-5 years old, or >15 years Both sexes Both sexes No seasonality No seasonality Clinical duration->1 year usually months ending in death Clinical duration->1 year usually months ending in death 17 month minimum incubation period 17 month minimum incubation period

Areas found

How to diagnose Sample a certain brain area Sample a certain brain area Test sample for BSE (Bovine spongiform encephalopathy) Test sample for BSE (Bovine spongiform encephalopathy)

Control strategies No treatment is available No treatment is available Inevitable fatality Inevitable fatality No vaccines available No vaccines available Quarantine Quarantine Depopulation Depopulation Harder to control in free-range animals Harder to control in free-range animals

Free-range control Selective culling of clinical suspects Selective culling of clinical suspects Localized population reduction in areas of high concentration Localized population reduction in areas of high concentration Tonsil biopsy as an antemortem test for CWD Tonsil biopsy as an antemortem test for CWD

What to do Contact wildlife management officials Contact wildlife management officials –Pennsylvania Game Commission –US Fish and Wildlife Service

A PA threat? What do you think?