Transmissible Spongiform Encephalopathies (TSE’s) - PowerPoint PPT Presentation

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Transmissible Spongiform Encephalopathies (TSE’s)

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  1. Transmissible Spongiform Encephalopathies (TSE’s)

  2. Deer Brain Tissue Normal CWD Spongiform Vacuoles Neurons

  3. Transmissible Spongiform Encephalopathies (TSE’s) Animal TSE’s Human TSE’s CJD vCJD BSE CWD Scrapie Others Others BSE Prevention

  4. Forms of Transmissible Spongiform Encephalopathies (TSE’s) • Sporadic • Inherited • Acquired • Iatrogenic

  5. Characteristics of all TSE’s • Central Nervous System Failure • Long Incubation Period • No Cure • Death

  6. HumanTransmissible Spongiform Encephalopathies • Creutzfeldt-Jakob Disease (CJD) • Fatal Familial Insomnia (FFI) • Gerstmann-Straussler Syndrome (GSS) • Kuru • Variant Creutzfeldt-Jakob Disease (vCJD)

  7. AnimalTransmissible Spongiform Encephalopathies • Scrapie • Transmissible Mink Encephalopathy (TME) • Chronic Wasting Disease (CWD) • Bovine Spongiform Encephalopathy (BSE)

  8. 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

  9. Cause? • Agent not fully characterized • Smaller than smallest known virus • No detectable immune or inflammatory response • Disinfectants • 600oC (1112oF) • 3 year burial

  10. Agent Theories • VIRUS • VIRION • PRION

  11. Agent Theories • VIRUS • VIRION • PRION

  12. vCJD from BSE? • vCJD -Human • BSE – Cattle • Prion Protein is Indistinguishable • Feline Spongiform Encephalopathy (FSE) • TSE in Kudu and Nyala

  13. Confirmed Cases BSE in UK C O W S Data from Office International Des Epizooties

  14. Confirmed Cases of Variant Creutzfeldt Jakob Disease in UK P E O P L E

  15. UK CowsBSE UK PeoplevCJD

  16. BSE Diagnostics • No live animal test • Need brain tissue • “Negatives” do not guarantee absence of infectivity

  17. Distribution of Infectivity • NeverFound in • Milk • Skeletal muscle of food animals spinal cord dorsal root ganglia brain trigeminal ganglia eye bone marrow distal ileum

  18. Distribution of Infectivity BSE in Sheep pituitary brain spinal cord vagus nerve Blood lymph nodes spleen intestine

  19. Prevention in U.S. • Import Regulations • Feed Rule • Surveillance • Formal Risk Assessment • Response Plan

  20. 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

  21. Import Restrictions - Europe • December 2000 – all rendered animal protein regardless of species Import Regulations • Restrictions extended to Japan September 2001 • Evaluations of other countries

  22. Milk Products • Blood Products • Gelatin • Pure Swine (Pork) • Pure Equine (Horse) • Plate Waste U.S. Feed Rule Prohibits Feeding Ruminants Mammalian Proteinexcept:

  23. Pure Swine (Pork) • Pure Equine (Horse) U.S. Feed Rule Prohibits Feeding Ruminants Mammalian Proteinexcept: • Milk Products • Blood Products • Gelatin • Plate Waste

  24. Confirmed Cases BSE in UK C O W S Feed Ban

  25. BSE Samples May 1990 through September 30, 2002 C O W S Total 36,594 40 Year Data from USDA APHIS NVSL

  26. Formal Risk Assessment • Harvard / Tuskegee Universities • Began in 1998 • Released November 30, 2001

  27. 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.

  28. 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.”

  29. BSE Response Plan • First version early 1990's • Updated often to reflect new scientific knowledge and personell changes.

  30. Plan Expectations • Herd Quarantined • Presumptive Positive Sample Hand Carried to UK for Confirmation. • Herd Purchased and Destroyed by Government • Trace Animals and Feed

  31. 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.

  32. 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

  33. BSE NEVERFound in U.S.

  34. http://www.wa.gov/agr Neil Lanning nlannning@agr.wa.gov 360-902-2052

  35. 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

  36. Brain Stem

  37. Brain Stem

  38. DeerBrain Tissue Normal Sectioning Artifact Neurons BloodVessel Nuclei of Glial Cells

  39. Deer Brain Tissue Chronic Wasting Disease Nuclei of Glial Cells Neurons Neuron Spongiform Vacuoles Blood Vessel

  40. Salt

  41. BoneMeal

  42. Mill Run

  43. Mill Run

  44. Mill Run and Bone Meal