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Transmissible Spongiform Encephalopathies (TSE’s) Deer Brain Tissue Normal CWD Spongiform Vacuoles Neurons Transmissible Spongiform Encephalopathies (TSE’s) Animal TSE’s Human TSE’s CJD vCJD BSE CWD Scrapie Others Others BSE Prevention
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Deer Brain Tissue Normal CWD Spongiform Vacuoles Neurons
Transmissible Spongiform Encephalopathies (TSE’s) Animal TSE’s Human TSE’s CJD vCJD BSE CWD Scrapie Others Others BSE Prevention
Forms of Transmissible Spongiform Encephalopathies (TSE’s) • Sporadic • Inherited • Acquired • Iatrogenic
Characteristics of all TSE’s • Central Nervous System Failure • Long Incubation Period • No Cure • Death
HumanTransmissible Spongiform Encephalopathies • Creutzfeldt-Jakob Disease (CJD) • Fatal Familial Insomnia (FFI) • Gerstmann-Straussler Syndrome (GSS) • Kuru • Variant Creutzfeldt-Jakob Disease (vCJD)
AnimalTransmissible Spongiform Encephalopathies • Scrapie • Transmissible Mink Encephalopathy (TME) • Chronic Wasting Disease (CWD) • Bovine Spongiform Encephalopathy (BSE)
AnimalTransmissible Spongiform Encephalopathies • Scrapie in Sheep and Goats • Transmissible Mink Encephalopathy (TME)in Mink • Chronic Wasting Disease (CWD)in Deer and Elk • Bovine Spongiform Encephalopathy (BSE) • in Cattle, Cats, Kudu, and Nyala
Cause? • Agent not fully characterized • Smaller than smallest known virus • No detectable immune or inflammatory response • Disinfectants • 600oC (1112oF) • 3 year burial
Agent Theories • VIRUS • VIRION • PRION
Agent Theories • VIRUS • VIRION • PRION
vCJD from BSE? • vCJD -Human • BSE – Cattle • Prion Protein is Indistinguishable • Feline Spongiform Encephalopathy (FSE) • TSE in Kudu and Nyala
Confirmed Cases BSE in UK C O W S Data from Office International Des Epizooties
Confirmed Cases of Variant Creutzfeldt Jakob Disease in UK P E O P L E
UK CowsBSE UK PeoplevCJD
BSE Diagnostics • No live animal test • Need brain tissue • “Negatives” do not guarantee absence of infectivity
Distribution of Infectivity • NeverFound in • Milk • Skeletal muscle of food animals spinal cord dorsal root ganglia brain trigeminal ganglia eye bone marrow distal ileum
Distribution of Infectivity BSE in Sheep pituitary brain spinal cord vagus nerve Blood lymph nodes spleen intestine
Prevention in U.S. • Import Regulations • Feed Rule • Surveillance • Formal Risk Assessment • Response Plan
Import Restrictions - countries with BSE • July 1989 - live ruminants • November 1989 - ruminant products Import Regulations • Import Restrictions - Europe • December 1997 • All live ruminants and most ruminant products
Import Restrictions - Europe • December 2000 – all rendered animal protein regardless of species Import Regulations • Restrictions extended to Japan September 2001 • Evaluations of other countries
Milk Products • Blood Products • Gelatin • Pure Swine (Pork) • Pure Equine (Horse) • Plate Waste U.S. Feed Rule Prohibits Feeding Ruminants Mammalian Proteinexcept:
Pure Swine (Pork) • Pure Equine (Horse) U.S. Feed Rule Prohibits Feeding Ruminants Mammalian Proteinexcept: • Milk Products • Blood Products • Gelatin • Plate Waste
Confirmed Cases BSE in UK C O W S Feed Ban
BSE Samples May 1990 through September 30, 2002 C O W S Total 36,594 40 Year Data from USDA APHIS NVSL
Formal Risk Assessment • Harvard / Tuskegee Universities • Began in 1998 • Released November 30, 2001
Harvard / TuskegeeRisk Assessment • Describe potential pathways of BSE infectivity into national herd or food supply. • Characterize and quantify steps in pathways. • Identify key steps for research or risk management.
Harvard/Tuskegee StudyConclusion • “Our analysis finds that the U.S. is highly resistant to any introduction of BSE or a similar disease.” • “BSE is extremely unlikely to become established in the U.S.”
BSE Response Plan • First version early 1990's • Updated often to reflect new scientific knowledge and personell changes.
Plan Expectations • Herd Quarantined • Presumptive Positive Sample Hand Carried to UK for Confirmation. • Herd Purchased and Destroyed by Government • Trace Animals and Feed
Producer Preventive Actions • Look for and obey cautionary statement “Do Not Feed Cattle or Other Ruminants” on feed labels. • Be aware that Pet Food often contains prohibited materials. • Avoid cross contamination of ruminant feed with feeds that contain prohibited material. • Keep feed records.
Record Keeping Requirement for Ruminant Producers • Any feeds fed containing any animal protein, regardless of species fed, excluding pet food fed to pets. • Invoices – date, quantity, supplier • Feed Labels • Minimum of 1 year
http://www.wa.gov/agr Neil Lanning nlannning@agr.wa.gov 360-902-2052
Scrapie ID Program http://www.aphis.usda.gov/vs/scrapie.htm http://animalagriculture.org/scrapie/scrapie.htm Linda.V.Carpenter@aphis.usda.gov Olympia Office USDA APHIS VS 360-753-9430
DeerBrain Tissue Normal Sectioning Artifact Neurons BloodVessel Nuclei of Glial Cells
Deer Brain Tissue Chronic Wasting Disease Nuclei of Glial Cells Neurons Neuron Spongiform Vacuoles Blood Vessel