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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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Transmissible Spongiform Encephalopathies (TSE’s)

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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


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


BSE NEVERFound in U.S.


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


Brain Stem


Brain Stem


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


Salt


BoneMeal


Mill Run


Mill Run


Mill Run and Bone Meal


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