Post on 24-Feb-2022
BSE UpdateBSE UpdateMeat Industry PerspectiveMeat Industry Perspective
Randall Huffman, Ph.D.Randall Huffman, Ph.D.V.P. Scientific AffairsV.P. Scientific Affairs
American Meat Institute FoundationAmerican Meat Institute Foundation
OverviewOverview
BSE and how it spreadsBSE and how it spreads
Control measures for BSEControl measures for BSE
Safety of North American Safety of North American beefbeef
What is BSE?What is BSE?Bovine Spongiform EncephalopathyBovine Spongiform Encephalopathy
Family of Transmissible Family of Transmissible Spongiform Encephalopathy (TSE) Spongiform Encephalopathy (TSE) diseasesdiseases
Fatal neurological disease of Fatal neurological disease of cattlecattle
Believed to be caused by Believed to be caused by misshapen prionsmisshapen prions
BSE first identified in 1986 in BSE first identified in 1986 in EnglandEngland
Linked to variant CJD in humans Linked to variant CJD in humans in 1996in 1996
The Global Spread of The Global Spread of BSEBSE
19861989
1991
1994
1997
1997 2000
2000
2000
1990
2001
2001
2002
2001
2001
2001
Israel2002
Japan2001
CanadaUSA2003
Variant Creutzfeld-Jakob(vCJD) first described
Epidemic Peak
Feed ban implemented
First BSE case confirmed by histopathology
Lag time for initial feed ban effect
Compliance challengesand
Incubation variability
Silent phase
Investigation and
Analysis
Lessons from the UK BSE epidemic curve
BSE
Year of onset
vCJD
40
35
30
25
20
15
10
5
0
Worldwide Cases of BSE and vCJDWorldwide Cases of BSE and vCJD
Scientific Principles of Scientific Principles of BSE PreventionBSE PreventionCattle
Feed
Cattle
Beef Processing
Consumer
Block recycling of rendered ruminant proteins into cattle feed
Exclude affected tissues and minimizecross- contamination
USDA BSE FirewallsUSDA BSE FirewallsBefore December 2003Before December 2003
Ban on imports from countries Ban on imports from countries that have had a case of BSEthat have had a case of BSE
Surveillance testing of high Surveillance testing of high risk cattlerisk cattle
FDA feed ban on feeding FDA feed ban on feeding mammalian proteins to cattle mammalian proteins to cattle
Strengthened USDA BSE RegulationsStrengthened USDA BSE Regulations(Implemented on January 12, 2004)(Implemented on January 12, 2004)
Ban nonBan non--ambulatory cattleambulatory cattle
Ban Ban SRM’sSRM’s from cattle over 30 monthsfrom cattle over 30 months
Ban small intestine and tonsil from all Ban small intestine and tonsil from all cattlecattle
Ban airBan air--injected stunninginjected stunning
Test and hold policy required for all Test and hold policy required for all cattle tested for BSEcattle tested for BSE
Additional control on Advanced Meat Additional control on Advanced Meat recoveryrecovery
BSE Precautionary ProceduresBSE Precautionary Procedures
Pre Harvest
Pre Slaughter
Beef Slaughter
Carcass Chilling
Carcass Disassembly
Rendering
FDA Ruminant Feed Ban
Feed Affidavit
Feedlot Review
Downer purchase policy
Ante-mortem inspection
Non-ambulatory policy
No air injection stunning
Dentition
Age Segregation [30 mo. of age and older]
SRM control program –tonsils, brain, spinal cord, skull and Ileum removal
Carcass Segregation
[30 mo. of age and older]
Carcass Segregation [30 Months of Age and Older]
SRM Control Program
Vertebral Column Removal
AMR Control Program
Feed prohibition
Labeling
Segregation of edible and inedible
Rendered sales designation
Rail car clean-out procedure
Live Cattle ReceivingLive Cattle ReceivingLive Animal
Receiving Program
Non-Ambulatory [USDA Condemned]
Rejected to Off-Site Disposal
CNS Suspect USDA Condemned
disposed of by incineration or Landfill
Ambulatory and USDA
Ante-Mortem Passed
Dead-On-Arrival [From Non-Ante-
Mortem Passed Stock] Rejected to Off-Site
Disposal
Ante-Mortem Rejected [USDA Condemned]
Off-Site Disposal
SRM Removal SRM Removal -- SlaughterSlaughter
Cattle 30 Months of Age and OlderCattle 30 Months of Age and Older
Spinal Cord Spinal Cord –– Inedible RenderingInedible Rendering
Brain Brain –– Inedible RenderingInedible Rendering
Skull Skull –– Inedible RenderingInedible Rendering
Eyes Eyes –– Inedible RenderingInedible Rendering
All Carcasses Regardless of AgeAll Carcasses Regardless of Age
Tonsils Tonsils –– Inedible RenderingInedible Rendering
Distal Ileum Distal Ileum –– Inedible RenderingInedible Rendering
SRM Removal and Control SRM Removal and Control –– Carcass DisassemblyCarcass Disassembly
Vertebral Column [DRG] is removed from Carcasses Vertebral Column [DRG] is removed from Carcasses 30 months of age and older and sent to inedible 30 months of age and older and sent to inedible rendering.rendering.
Removal of Vertebral Column [DRG]
Washing / Sanitizing of Affected Equipment after >30 month old.
Beef SafetyBeef Safety
Beef is safe, even from countries Beef is safe, even from countries with many cases of BSE in cattle with many cases of BSE in cattle herdherd
Specific tissues (SRM) are the only Specific tissues (SRM) are the only source of potential contamination.source of potential contamination.
SRM are only contaminated if the SRM are only contaminated if the animal has the disease.animal has the disease.
Harvard Study clearly demonstrates Harvard Study clearly demonstrates that U.S. herd is very resistant to that U.S. herd is very resistant to disease disease
Tissue Infectivity by AgeTissue Infectivity by Age
Spinal CordDorsal Root Ganglia
Brain
Distal Ileum
Trigeminal gangliaTonsils
Retina3rd Eyelid
Distal Ileum
Tonsils
Over 30 Months of Age Under 30 Months of Age
USDA Specified Risk Material Ban USDA Specified Risk Material Ban Protects Beef SafetyProtects Beef Safety
No evidence to date of BSE No evidence to date of BSE agent in beef muscleagent in beef muscle
No BSE agent detected in bone No BSE agent detected in bone marrow, marrow, buffybuffy coat, serum, coat, serum, blood clot, lymph node, fetal blood clot, lymph node, fetal calf serum, spleen from calf serum, spleen from clinical BSE cases.clinical BSE cases.
Surveillance TestingSurveillance Testing
Requires a sample from the Requires a sample from the obexobex of the of the brain stembrain stem
Detectable with the laboratory assay Detectable with the laboratory assay only 3 only 3 –– 6 months prior to clinical 6 months prior to clinical signs of diseasesigns of disease
Bioassay remains the most sensitive test Bioassay remains the most sensitive test methodmethod
Histopathology is used in surveillance Histopathology is used in surveillance systems worldwide and the U.S.systems worldwide and the U.S.
Rapid screening methods are now approved Rapid screening methods are now approved and being used by USDAand being used by USDA
APHIS SurveillanceAPHIS Surveillance(one(one--time program for 12 time program for 12 ––18 months)18 months)
Total adult cattle population Total adult cattle population 45 45 millionmillion
At risk cattle populationAt risk cattle population ----446,000446,000
APHIS will sample as many of these from APHIS will sample as many of these from the at risk population as possiblethe at risk population as possible–– IF 201,000 sampled, 95% confidence that the IF 201,000 sampled, 95% confidence that the program will detect the disease if it exists program will detect the disease if it exists at 1case/10,000,000at 1case/10,000,000
–– IF 268,000 sampled, 99% confidence that the IF 268,000 sampled, 99% confidence that the program will detect the disease if it exists program will detect the disease if it exists at 1case/10,000,000at 1case/10,000,000
Additional 20,000 healthy adult cattle Additional 20,000 healthy adult cattle ill b l dill b l d
Science of BSE testingScience of BSE testingScience of BSE testing
Potential BSEExposure
Birth 6 12 24 30 36 44 50
Months of Age60
Clinical OnsetOf BSE
BSE test kits only detect disease about 6 months prior to clinical onset
80% harvested < 30 mos
Average incubation = 60 moYoungest UK case 2002 = 51 mo
Tracking youngest casesTracking youngest casesin UK epidemicin UK epidemic
4242
4040
0000
5656
4848
0101
5252
5151
0202
555541413636303030302626242427273333Second Second
YoungestYoungest
505039393434292930302020242424243030Age Age
YoungestYoungest
030399999898969694949292909088888686Year OnsetYear Onset
Increasing minimum age suggest smaller exposure
SummarySummary
USDA has had aggressive, USDA has had aggressive, scientifically sound BSE control scientifically sound BSE control measures in place for many years.measures in place for many years.USDA has strengthened regulations.USDA has strengthened regulations.Beef is safe.Beef is safe.Consumer confidence in the safety of Consumer confidence in the safety of beef remains high.beef remains high.