MANAGEMENT OF TRANSMISSIBLE

MANAGEMENT OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIESIN MEAT PRODUCTION

4

Dagmar HeimJörg Löpfe

Elizabeth MumfordAndrew Speedy

FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONSRome, 2007

CApACITy BUILDING FOR SURvEILLANCE AND pREvENTION OF BSE AND OTHER ZOONOTIC DISEASES

course manual

The designations employed and the presentation of material in this information product do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations concerning the legal or development status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.

All rights reserved. Reproduction and dissemination of material in this information product for educational or other non-commercial purposes are authorized without any prior written permission from the copyright holders provided the source is fully acknowledged. Reproduction of material in this information product for resale or other commercial purposes is prohibited without written permission of the copyright holders. Applications for such permission should be addressed to the Chief, Electronic Policy and Support Branch, Communication Publishing Division, FAO, Viale delle Terme di Caracalla, 00153 Rome, Italy or by e-mail to [email protected]

© FAO 2007

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CONTENTS

Foreword v

Courseobjectives vii

INTRODUCTION TO TRANSmISSIBLE SpONGIFORm ENCEpHALOpATHIES

1. Transmissible spongiform encephalopathies 12. Bovine spongiform encephalopathy 33. Measures for control and prevention 54. Clinical signs 105. Diagnosis of BSE 116. Surveillance systems 147. Risk assessment 168. References 17

OvERvIEw: ImpLEmENTATION OF TRANSmISSIBLE SpONGIFORm ENCEpHALOpATHIES mEASURES IN mEAT pRODUCTION

1. General concepts 212. Control on the farm 213. Control at the slaughterhouses and processing plants 224. Control of cattle not fit for normal slaughter 225. References 23

REGULATIONS AND STANDARDS FOR THE mEAT INDUSTRy

1. General concepts 252. The players: Who sets the standards? 253. References 32

TRANSmISSIBLE SpONGIFORm ENCEpHALOpATHIES mANAGEmENT AT THE FARm LEvEL

1 General concepts 352. Livestock feeds and feeding 353. Identification and notification of suspect cases 354. Industry standards 365. Transport 366. Animal identification and documentation 377. References 37

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TRANSmISSIBLE SpONGIFORm ENCEpHALOpATHIES mANAGEmENT AT THE SLAUGHTERHOUSE

1. General concepts 392. Animal identification 393. Arrival and ante mortem examination 394. Stunning, pithing and bleeding 405. Hide and head removal 416. Sampling 417. Carcass splitting and spinal cord removal 428. Control of cross contamination 439. Inspection and identification of specified risk material 4310. Disposal of specified risk material 4411. References 44

TRANSmISSIBLE SpONGIFORm ENCEpHALOpATHIES mANAGEmENT AT THE pROCESSING pLANT

1. General concepts 452. SRM control 453. Deboning and handling of SRM 454. Mechanically recovered meat 465. References 46

QUALITy CONTROL CONCEpTS, HyGIENE, AND HACCp IN THE mEAT INDUSTRy

1. General concepts 472. Quality control 473. Facility design 484. Hygiene and sanitation 485. HACCP 496. References 49

AppENDIX 1

Course contributors and staff 51

AppENDIX 2

Related background reading and web links 55

AppENDIX 3

Glossary of technical terms and acronyms 61

AppENDIX 4

Project summary 69

v

FOREwORD

Tosupportcountrieswitheconomiesintransitionanddevelopingcountriesinthecon-trol and prevention of bovine spongiform encephalopathy (BSE), the project CapacityBuilding for Surveillance and Prevention of BSE and Other Zoonotic Diseases, is theresult of collaboration between the Food and Agriculture Organization of the UnitedNations(FAO),SafeFoodSolutionsInc.(SAFOSO,Switzerland)andnationalveterinaryofficesinpartnercountries,andfundedbytheGovernmentofSwitzerland.

Theaimoftheproject istobuildcapacity,establishpreventivemeasuresandana-lyserisksforBSE.PartnercountriesarethusenabledtodecreasetheirBSErisktoanacceptablelevelordemonstratethattheirBSEriskisnegligible,andtherebyfacilitateregional and international trade under the Agreement on the Application of SanitaryandPhytosanitaryMeasures(SPSAgreement)oftheWorldTradeOrganization(WTO).Abriefprojectsummaryisincludedasanappendixtothiscoursemanual.

Activitiesoftheproject:• Thespecificneedsofpartnercountriesareassessed.• Fourcomprehensivecoursesto“trainthetrainers”areprovidedtoselectedpar-

ticipantstoimproveunderstandingoftheepidemiologyofandrelevantriskfac-torsforBSEandtransmissiblespongiformencephalopathy(TSE)andtodevelopspecificknowledgeandskillsforimplementingappropriatecontrols.

• Inathirdstep, in-countrycoursesareheldbytrainednationalpersonnel inthelocallanguageandaresupportedbyanexperttrainer.

FAOhasthemandatetoraiselevelsofnutritionandstandardsofliving,toimproveagriculturalproductivityandthelivelihoodsofruralpopulations.Surveillanceandcon-trolofdiseasesofveterinarypublichealthimportancearecontributionstothisobjec-tive.SAFOSO,aprivateconsultingfirmbasedinSwitzerland,isprovidingthetechnicalexpertiseforthisproject.

This manual is a supplement to the training course Management of transmissiblespongiformencephalopathiesinmeatproduction,whichisgivenwithintheframeworkoftheproject.Thispracticalcourseistargetedatgovernmentalandindustryperson-nel who will contribute to the development and implementation of the national BSEsurveillanceandcontrolprogramme,andtotheBSEriskassessmentforthepartnercountries.

Theinformationincludedinthemanualisnotintendedtobecompleteortostandonitsown.Forfurtherreading,specificreferencesareincludedattheendofthechapters.General background material and Web links, and a glossary of terms and frequentlyusedacronyms,areincludedasappendices.

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ThepreparationofthismanualwasacollaborativeeffortofthetrainersoftheMan-agement of transmissible spongiform encephalopathies in meat production courseoffered in Switzerland and the project staff. The content of the manual reflects theexpertiseandexperienceoftheseindividuals.FAOandSAFOSOaregratefultothepro-fessionalspreparingthemanualandtotheGovernmentofSwitzerlandforfundingthispublic–privatepartnershipprojectinsupportofsaferanimalproductionandtrade..

Samuel C. Jutzi Ulrich Kihm Director Director FAOAnimalProductionandHealthDivision SafeFoodSolutions Rome,Italy Berne,Switzerland

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COURSE OBJECTIvES

Upon completion of the lectures and exercises of the course on Management oftransmissiblespongiformencephalopathiesinmeatproduction,oftheprojectCapac-ityBuilding forSurveillanceandPreventionofBSEandOtherZoonoticDiseases, theparticipantsshould:

• understandbasicprinciplesofmanagement inmeatproduction,brainsamplingandpathogencontrolforanimaldiseasesingeneralandBSEandTSEsinparticu-lar;

• beabletoapplytheacquiredknowledgepracticallyintheirdailyjobactivities• beabletotransferthisknowledgeeffectivelytoothers

Specifically,theseprinciplesinclude:• basic informationonBSEandTSEs, including transmission,pathogenesis, risk

factorsandepidemiology;• internationalandnationalregulationsinmeatproduction,includingguidelinesfor

theuseofanimalby-products;• knowledgeofcriticalfactorsforBSEandTSEcontrolateachstepintheproduc-

tionchain,includingatthefarm,slaughterhouseandprocessingplantlevels• qualitycontrolandSRMcontrolmeasuresateachproductionstep;• meat inspection,assessmentofmeatproductionplantsandHACCPprinciples,

includingoversightinimplementationofBSEcontrolmeasures;• categorizationofanimalby-productsandtherisksofanimalby-productsinani-

malfeed;• collectingsamplesforBSEtestingofslaughteredanimals,includingtheappro-

priatetechnicalskills.

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Introduction to

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INTRODUCTION TO TRANSmISSIBLE SpONGIFORm ENCEpHALOpATHIES

1. TRANSmISSIBLE SpONGIFORm ENCEpHALOpATHIESTransmissible spongiform encephalopathies (TSE) are a class of neurodegenerativediseasesofhumansandanimalscharacterizedbyspongiformdegenerationofthebrainandtheassociatedneurologicalsigns.TSEsareslowlydevelopinganduniformlyfatal.

Diseasesincludekuru,Gerstmann-Sträussler-ScheinkersyndromeandCreutzfeldt-Jakobdisease(allinhumans),scrapie(insheepandgoats),felinespongiformencepha-lopathy (FSE; in cats), bovine spongiform encephalopathy (BSE; in cattle), chronicwasting disease (CWD; in cervids) and transmissible mink encephalopathy (TME; inmink).MostoftheseTSEshadalreadybeenreportedbeforethefirstdetectionofBSE(Figure1)(Lasmezas,2003).

FIGURE 1

year in which the various TSEs were first reported

1700 1750 1800 1850 1900 1950 2000

Variant Creutzfeldt Jakob disease

Feline spongiform encephalopathy

Bovine spongiform encephalopathy

Chronic wasting disease

Transmissible mink encephalopathy

Gerstmann-Sträussler-Scheinker syndrome

Creutzfeldt Jakob disease

Kuru

Scrapie

The TSE with the longest history is scrapie, which was recognized as a disease ofsheepinGreatBritainandothercountriesofwesternEuropemorethan250yearsago(DetwilerandBaylis,2003).Scrapiehasbeenreportedinmostsheep-raisingcountriesthroughouttheworldwithfewnotableexceptions(e.g.Australia,NewZealand).

Transmissible mink encephalopathy (TME) was first described in 1947. It is a rarediseaseoffarmedminkandhasbeenrecordedincountriesincludingtheUnitedStatesofAmerica(USA),Canada,Finland,GermanyandtheRussianFederation.ContaminatedfeedissuspectedtobethemainsourceofTMEinfection.

Chronicwastingdisease(CWD)incaptiveandfree-roamingNorthAmericandeerandelkwasfirstdescribedinthe1960s.Initially,caseswereonlyreportedincaptivedeerandelkinColorado(USA),butCWDincaptiveand/orfreeroamingdeer,elkandmoosehasnowbeenreportedinseveralotherstatesintheUSAandinareasofCanada.TheoriginofCWDisstillunknown.

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Scrapie, kuru, Creutzfeldt-Jakob disease, Gerstmann-Sträussler-Scheinker syn-drome,TME,andCWDarebelievedtobedistinctfromBSE.However,straintypinghasindicatedthatsomeotherTSEsarecausedby thesamestrainof theTSEagent thatcausesBSEincattle.OnlyfouryearsaftertheinitialBSEcaseshadbeendiagnosedincattleintheUnitedKingdomofGreatBritainandNothernIreland(UK),BSEindomes-ticcats(felinespongiformencephalopathy/[FSE])wasfirstreported.Almostalloftheapproximately100FSEcasesdiagnosedworldwideoccurredintheUK.Themostwidelyacceptedhypothesis is that theaffecteddomesticcatswereexposedtoBSE infectiv-ity throughcontaminatedcommercialcat feedor freshslaughteroffal thatcontainedbrainorspinalcordfrombovineBSEcases.SeverallargecatskeptinzooswerealsodiagnosedwithFSE.Theseincludedcheetahs,lions,ocelots,pumasandtigers.AllofthelargecatsthatwerediagnosedwithFSEoutsidetheUKoriginatedfromUKzoos.It issuspected that these largecatsacquired the infectionbybeing fedcarcassesofBSE-infectedcattle.

NotlongafterBSEwasdiagnosedincattle,sporadiccasesofBSEinexoticruminants(kudus,elands,Arabianoryx,ankolecows,nyala,gemsbockandbison)werediagnosedinBritishzoos.OnezebuinaSwisszoowasalsoBSEpositive.Inthemajorityofthesecases,exposuretoanimalfeedproducedwithanimalprotein(andthereforepotentiallycontainingBSEinfectivity)waseitherdocumentedorcouldnotbeexcluded.

Moreover,therehaslongbeenconcernthatsheepandgoatscouldhavebeenexposedtoBSE,becauseithasbeenexperimentallydemonstratedthatBSEcanbeorallytrans-mittedtosmallruminants(SchreuderandSomerville,2003). In2005,thefirstcaseofBSEinagoatwasconfirmedinFrance(Eloitetal.,2005),thoughtherehavebeennocon-firmedBSEcasesinsheeptodate.ItisdifficulttodistinguishbetweenscrapieandBSEinsheep,asdifferentiationiscurrentlynotpossiblebyclinicalorpathologicalmeans.

SeveralTSEshavebeenreportedtooccurinhumans,includingtwoformsofCreut-zfeldt-Jakobdisease(sporadicCJDandvariantCJD[vCJD]),Kuru,Gerstmann-Sträus-sler-Scheinkersyndrome,aswellas fatal familial insomnia.Of these,onlyvCJDhasbeenassociatedwithBSE.SporadicCJDwasfirstidentifiedin1920asanencephalopa-thyoccurringalmostexclusivelyinelderlypatientsworldwide.TheincidenceofsporadicCJD isapproximately0.3–1.3casespermillion individualsperyear,and issimilar inmostcountries.Thedurationofthediseaseisapproximatelysixmonths.Approximately80-89%ofCJDcasesarebelievedtobesporadic,10%arefamilial(aresultofaheritablemutationinthePrPgene),andtheremainderarebelievedtobeiatrogenic.

VariantCJDwasfirstreportedinMarch1996intheUK(Willetal.,1996).IncontrasttosporadicCJD,patientsareyoung(averageage29years)andthedurationofthediseaseis longer(average22months).Epidemiologically, little isknownaboutvCJD. Insomecasesthediseasewasseeningeographicalclusters,andthereareindicationsthatspe-cialconsumptionpatternsmayhaveplayedarole.Geneticfactorsmayalsoplayaroleininfection,aspatientswithclinicaldiseasehavebeenhomozygousformethionineatcodon129oftheprionproteingene.InEurope,thisgenotypeaccountsforapproximately30%ofthepopulation.

The expected course of the vCJD epidemic is difficult to predict, since importantvariablessuchashumanexposurerate,theinfectiousdose,theincubationperiodandhumansusceptibilityarelargelyunknown.Thepredictions initiallyrangedfromafewhundredtoafewmillionexpectedcases.However,thelowerpredictionsaremoreprob-ablebasedonthecurrentincidenceofvCJDcases(Figure2).

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Introduction to

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ThelinkbetweenBSEandvCJDiscommonlyaccepted.Initially,thetemporospatialassociationoftheoutbreakssuggestedacausalrelationship.Experimentally,inocula-tionoftheBSEagentintothebrainsofmonkeysproducesfloridplaqueshistologicallyidenticaltothosefoundinthebrainsofvCJDpatients.Inaddition,theagentsassociatedwithBSEandvCJDaresimilar,bothbyglycotyping(evaluatingtheglycosylationpattern)andbystraintyping,whereastheprionsassociatedwithotherTSEs(suchassporadicCJD,scrapieandCWD)aredifferent.

2. BOvINE SpONGIFORm ENCEpHALOpATHy2.1. Origin and spreadBSEwasfirstdiagnosedincattleintheUKin1986(Wellsetal.,1987).Extensiveepide-miologicalstudieshavetracedthecauseofBSEtoanimalfeedcontaininginadequatelytreated ruminant meat and bone meal (MBM) (Wilesmith et al., 1988). Although ele-mentsofthescenarioarestilldisputed(e.g.originoftheagent;Wilesmithetal.,1991;Princeetal.,2003;SSC,2001a), itappears likely thatchanges inUKrenderingproc-essesaround1980allowedtheetiologicalagenttosurviverendering,contaminatetheMBMandinfectcattle.Someoftheseinfectedcattlewouldhavebeenslaughteredatanolderage,andthereforewouldhavebeenapproachingtheendoftheBSEincuba-tionperiod.Potentially, theyhadnoclinical signsor thesignsweresubtleandwentunrecognized,thoughthecattlewouldhaveharbouredinfectivitylevelssimilartothoseseen inclinicalBSEcases.Thewasteby-products from thesecarcasseswould thenhavebeenrecycledthroughtherenderingplants,increasingthecirculatinglevelofthepathogen(whichbynowwouldhavebecomewelladaptedtocattle)intheMBM,thuscausingtheBSEepidemic.

In1989thefirstcasesoutsidetheUK,intheFalklandIslandsandOman,wereidenti-fiedinlivecattlethathadbeenimportedfromtheUK.In1989Irelandreportedthefirstnon-imported(“native”or“indigenous”)caseoutsidetheUK,andin1990Switzerlandreportedthefirst indigenouscaseontheEuropeancontinent. Indigenouscaseswere

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

30

25

20

15

10

5

0

3

10

10

18

15

28

20 17

18

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FIGURE 2

Number of vCJD cases in the UK over time

Source:DepartmentofHealth,UK(2006)

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thenreportedinmanycountriesthroughoutEurope.In2001,JapanreportedthefirstindigenouscaseoutsideEurope,andthiscasehasbeenfollowedbyindigenouscasesinIsraelandNorthAmerica.1

2.2. EpidemiologyCattletestingpositiveforBSEhaverangedfrom20monthsto19yearsofage,althoughmostofthecasesarebetweenfourandsixyearsofage.Abreedorgeneticpredisposi-tionhasnotbeenfound.MostcasesofBSEhavecomefromdairyherds,likelyduetodifferencesinfeedingsystemswhencomparedtobeefcattle.Additionally,beefcattlearetypicallyyoungeratthetimeofslaughter.Becausetheaverageincubationperiodisfourtosevenyears,infectedbeefcattlewillgenerallynotlivelongenoughtodevelopclinicalsigns.

Thereisnoexperimentalorepidemiologicalevidencefordirecthorizontaltransmis-sionofBSE,andthereisstillcontroversyregardingthepotentialforverticaltransmis-sion.Noinfectivityhasthusfarbeenfoundinmilk(TAFS,2007;SSC,2001b),ova,semenor embryos from infected cattle (SSC 2002a, 2001c; Wrathall, 1997; Wrathall et al.,2002).SomeoffspringofBSEcasesintheUKwerealsoinfected,andacohortstudyofUKcattleconcludedthatverticaltransmissioncouldnotbeexcluded.However,theroleofvariationingeneticsusceptibilityorothermechanismsinthisconclusionisunclear,andnooffspringofBSEcaseshavebeenreportedwithBSEoutside theUK. Ifsomeamountofmaternaltransmissiondoesoccur,it isclearlynotenoughtomaintaintheepidemic,evenwithintheUK.

2.3. pathogenesis Intheearly1990s,infectivitystudiesofBSEincattlewereongoing.Atthattime,experi-mental inoculation of tissues from BSE-infected cattle into mice had only identifiedinfectivity inbraintissue.Therefore,definitionofspecifiedriskmaterials(SRM;thosetissuesmostlikelytobeinfective)wasbasedonscrapieinfectivitystudies.Scrapierep-licatesprimarilyinthelymphoreticularsystem,andscrapieinfectivityhasbeenfoundinnumerouslymphnodes,tonsils,spleen,lymphoidtissueassociatedwiththeintestinaltractandplacenta.Duringthelaterpreclinicalphase,infectivityisfoundinthecentralnervoussystem(CNS).Inaddition,scrapieinfectivityhasbeendetectedinthepituitaryandadrenalglands,bonemarrow,pancreas,thymus,liverandperipheralnerves(SSC,2002b).

The first resultsofBSEpathogenesisstudies, inwhichcalveswere intracerebrallyinoculatedwithtissuefromBSEfieldcasesandfromcattleexperimentallyinfectedbytheoral route,becameavailable in themid-1990s (Wellsetal.,1996;1998). Incattleexperimentally infectedby theoralroute,BSE infectivityhasbeen found in thedistalileumatspecificintervalsduringtheincubationperiod,startingsixmonthsafterexpo-sure(Wellsetal.,1994).Furthermore,CNS,dorsalrootgangliaandtrigeminalgangliawerefoundtobeinfectiveshortlybeforetheonsetofclinicalsigns.Recently,lowlevelsof infectivity early in the incubation period have been detected in the palatine tonsil.Inonestudy,sternalbonemarrowcollectedduringtheclinicalphaseofdiseasewasinfective;however,thisresulthasnotbeenreproduced(thereforeitmaypossiblyhavebeenduetocrosscontamination)(Wellsetal.,1999;Wells,2003).

1 CurrentthroughJanuary2007.

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2.4. TSE agentsAlthough some controversy still exists regarding the nature of the BSE agent, mostresearchersagreethataresistantprionproteinisthecauseofthedisease.Researchhasshowntheagenttobehighlyresistanttoprocessesthatdestroyothercategoriesofinfectiousagents,suchasbacteriaandviruses,andnonucleicacidhasbeenidenti-fied.

Ineukaryoticspecies,mostcellscontainanormalprionprotein,termedPrPC(super-script “C” for “cellular”).Thisprotein isnormallydegradablebyproteases.TSEsarethoughttobecausedbyanabnormal,infectiousformofPrPC,inwhichthestericconfor-mationhasbeenmodifiedandwhichishighlyresistanttoproteinasedegradation.ThisinfectiousformismostcommonlytermedPrPSc(initiallyfor“scrapie”),butmayalsobereferredtoasPrPBSEorPrPRes(fortheportionthatis“resistant”toaspecificproteinase,proteinaseK).BecauseprionproteinisverycloselyrelatedtothenormalcellularPrPCprotein,itdoesnotinducetheproductionofantibodiesininfectedanimals.

TheroleofPrPCinnormalanimalsisstillunderdiscussion.GeneticallymodifiedmicelackingthegeneforPrPC(andexpressingnoPrPC)canbeexperimentallyproduced,butthesemicehavenoobviousphysiologicalchangesthatcanbeattributedtolackingtheprotein.Theycannot,however,beinfectedexperimentallywithTSEagents.

3. mEASURES FOR CONTROL AND pREvENTION3.1. Aims of measuresTheultimateaimsofBSEcontrolandpreventionprogrammesaretoreduceexposureriskbothtocattleandtohumans(Figure3).Twolevelsofmeasuresmustthereforebeconsidered:

• thosethatblockthecycleofamplificationinthefeedchain;• thosethatpreventinfectivematerialfromenteringhumanfood.

Owing to the prolonged incubation period, it may be more than five years betweeneffective enforcement of measures and a detectable decrease in the number of BSEcases,i.e.beforetheeffectofthemeasuresisseen.Thisintervalmaybeevenlongerifthemeasuresarenotenforcedeffectively,asisusuallythecaseforsometimeafterimplementation.

FIGURE 3

Reducing BSE exposure risk to both cattle and humans

Blockamplification

EradicateBSE

Prevent the BSE agent from entering human food

Prevent animal exposure

Prevent human exposure

Recycling andamplification cycle in cattle

MeasuresIntermediate

goalsUltimate

aims

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RiskmanagementforBSEisnotgloballyharmonized.InEurope,thememberstatesoftheEuropeanUnion(EU)havecommonrulesfortheimplementationofmeasures,andothercountriesinEuropeandcountrieswantingtojointheEUareadaptingtheirmeasures accordingly. However, the implementation of these measures still variesconsiderablyfromonecountrytoanother.

3.2. measures to protect animal healthFeed bansRecognitionofMBMasasourceofinfectionledtobansonfeedingMBMtoruminantsinordertobreakthecycleofcattlere-infection(DEFRA,2004a;EC,2004;HeimandKihm,1999).Implementationofa“feedban”maymeandifferentthingsindifferentcountries.FeedscontainingMBMofruminantormammalianoriginmightbebanned,orthebanmight includeallanimalproteins (i.e.mammalianMBM, fishmealandpoultrymeal).Thebanmightprohibitfeedingofthematerialstoruminantsortoalllivestockspecies,ormightentirelyprohibituseofthematerial.

Insomecountries,afeedbanofruminantMBMtoruminantswasimplementedasthefirststep.ThebanwasthenoftenextendedtomammalianMBMduetothediffi-cultyindistinguishingbetweenheat-treatedMBMofruminantoriginandMBMofothermammalianorigin.Thisextendedbanwasgenerallyeasiertocontrolandenforce.

EvenwhennoMBMisvoluntarilyincludedincattlefeed,thereisstillariskofrecyclingtheagentthroughcrosscontaminationandcrossfeeding.ExperiencehasshownthatsmallamountsofMBMinfeedaresufficienttoinfectcattle.ThesetracesmayresultfromcrosscontaminationofMBM-freecattlefeedwithpigorpoultryfeedcontainingMBM,e.g.fromfeedmillsthatproducebothtypesoffeedinthesameproductionlines,fromtransportbythesamevehiclesorfrominappropriatefeedingpracticesonfarms.Apparently,usingflushingbatchesasasafeguardagainstsuchcrosscontaminationinfeedmills isnotsufficient.ThetracesofMBMincattlefeedthathavebeendetectedinEuropeancountriesaremostoftenbelow0.1%,whichseemstobeenoughtoinfectcattle.Therefore,aslongasfeedingofMBMtootherfarmedanimalsisallowed,crosscontaminationofcattlefeedwithMBMisverydifficulttoeliminate.Dedicatedproduc-tionlinesandtransportchannelsandcontroloftheuseandpossessionofMBMatfarmlevelarerequiredtocontrolcrosscontaminationfully. InmostEuropeancountries,abanonfeedingMBMtoallfarmanimalshasnowbeenimplemented.

MoredetailedinformationonmeasuresforlivestockfeedscanbefoundintheCapac-ityBuildingforSurveillanceandPreventionofBSEandOtherZoonoticDiseasesprojectcoursemanualentitledManagementoftransmissiblespongiformencephalopathiesinlivestockfeedsandfeeding(FAO,2007a).

Rendering parametersRenderingofanimalby-products(e.g.bovinetissuesdiscardedattheslaughterhouse)andfallenstockintoMBM,whichisthenfedtoruminants,canrecycletheagentandallowamplification.Whenrenderingprocessesareproperlyapplied,thelevelofinfec-tivityisreduced.Ithasbeendeterminedthatbatch(ratherthencontinuous)renderingat133ºCand3barsofpressurefor20minuteseffectivelyreducesinfectivity(providingthat the particle size is less than 50 mm) although it does not completely inactivatetheagent(Tayloretal.,1994;TaylorandWoodgate,1997,2003;OIE,2005a).Therefore,using these parameters does not guarantee absolute freedom from infectivity in the

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Introduction to

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MBM,especiallywhenmaterialwithhighlevelsofBSEinfectivityenterstherenderingprocess.

Moredetailed informationonmeasures forrenderingcanbe found in theCapacityBuilding forSurveillanceandPreventionofBSEandOtherZoonoticDiseasesprojectcoursemanualentitledManagementoftransmissiblespongiformencephalopathiesinlivestockfeedsandfeeding(FAO,2007a).

Specified risk materialsSpecifiedriskmaterials(SRM)aretissuesthathavebeenshown(orareassumed)tocontainBSEinfectivityininfectedanimals,andthatshouldberemovedfromthefoodand feedchains (TAFS,2004a). If thesematerialsareremovedatslaughterand thenincinerated, the risk of recycling the pathogen is markedly reduced. In addition, inordertoremoveinfectivityfurtherfromthefeedchain,carcassesfromhigh-riskcattle(e.g.fallenstock)shouldalsobetreatedasSRM.CountriesdefineSRMdifferently,anddefinitions sometimes change as new information becomes available, however mostdefinitionsincludethebrainandspinalcordofcattleover30months(Table1).

3.3. measures to prevent human exposureTheabovemeasurestoprotectanimalhealthindirectlyprotecthumanhealthbycon-trolling the amplification of the BSE agent. The most important direct measures forpreventinghumanexposure to theBSEagent in foodsaredescribed in the followingpages.

TABLE 1. A summary of designated SRm in Europe (as of October 200�)

Species and tissue European Union UK and portugal Switzerland

Age

CATTLE

Skull(includingbrainandeyes) >12months - >6months

Entirehead(excludingtongue) - >6months >30months

Tonsils Allages Allages Allages

Spinalcord >12months >6months >6months

Vertebralcolumn(includingdorsalrootgangliabutNOTvertebraeoftailortransverseprocessesoflumbarandthoracicvertebrae) >24months >30months >30months(includestail)

Intestinesandmesentery Allages Allages >6months

Spleen - >6months -

Thymus - >6months -

SHEEp AND GOATS

Skull(includingbrainandeyes) >12month >12months >12months

Spinalcord >12months >12months >12months

Tonsils >12months >12months Allages

Ileum Allages Allages Allages

Spleen Allages Allages Allages

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Ban of SRm and mechanically recovered meat for foodExcludingSRMandmechanically recoveredmeat (MRM) from thehuman foodchaineffectivelyminimizestheriskofhumanexposureandisthemostimportantmeasuretakentoprotectconsumers (TAFS,2004a).MRMisapastederived fromcompressedcarcasscomponentsfromwhichallnon-consumabletissueshavebeenremoved.Thesecarcasscomponentsincludebonesaswellasthevertebralcolumnwiththespinalcordanddorsalrootgangliaoftenattached.TheMRMisthenusedincookedmeatproducts,suchassausagesandmeatpies,and,ifruminantmaterialisincluded,isregardedasamajorBSEriskfactor.

BSE detection at slaughterMeasuresforminimizingrisksforhumanhealthrequiretheidentificationandelimina-tionofclinicallyaffectedanimalsbeforeslaughter,whichcanonlybeachievedthroughanadequatesurveillanceprogrammeincludinganantemorteminspectionspecificforBSE.BecausetheSRMfromclinicallyaffectedanimalsisknowntocontaininfectivity,removalanddestructionof theseanimalsprior toentering theslaughterhousehavetwoclearlypositiveeffects:

• Theriskofinfectivematerialenteringthefoodandfeedchainsisreduced.• There is lesscontaminationof theslaughterhouse,and lesspotential forcross

contaminationofnormalcarcasses.Inaddition,mostcountriesinEuropehavebeenconductinglaboratorytestingofall

slaughter cattle over 30 months of age (or even younger) for BSE since 2001 (TAFS,2004b).

Thebenefitsoftestingordinaryslaughtercattleare:• It identifies the very few positive animals that may not yet be showing clinical

signs.• Itdecreasestheriskofcontaminatedmaterialenteringthe foodchain in those

countrieswhereothermeasures(e.g.antemorteminspection,SRMremoval)maynotbeeffectivelyimplemented.

• Itcouldincreaseconsumerconfidenceinbeefandbeefproducts.• Itmayallowimportbanstobelifted(althoughsomeimportsbansmaybeinviola-

tionofWTOrules).

The drawbacks are:• Itisextremelyexpensive.• Itmaygiveafalsesenseofsecuritytoconsumers.• It may diminish the incentive to implement and enforce effectively other, more

effectivemeasures(suchasantemorteminspection).• Itcouldleadtoincreasedcontaminationwithinslaughterhousesduetoprocessing

ofagreaternumberofpositivecarcassesifothermeasuresarenotimplemented.

AllcurrentlyavailablemethodsfordiagnosingBSErelyonthedetectionofaccumulatedPrPScinthebrainofinfectedanimals.Therefore,cattlemusthavealreadybeenslaughteredbeforeconfirmationofdiseasestatuscanbemade,potentiallyincreasingtheriskofcontaminationofcarcasseswithaninfectiousagent.Topreventthis,identificationandremovalofclinicallyaffectedanimalsbythefarmerorveterinarianduringanantemorteminspectionareoptimalcontrolsteps.

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measures to avoid cross contamination of meat with SRmIthasbeenshownthattheuseofcertaintypesofcaptiveboltgunstostuncattlepriortoslaughtercausesbraintissuetoenterthebloodstreamthatcouldbedisseminatedthroughout the carcass (including muscle). Therefore, pneumatic bolt stunning andpithingarenowforbiddenbymanycountriesinEuropeandelsewhere.Hygienicmeas-urestakenintheslaughterhousetoreducepotentialcontaminationofmeatwithSRMarealsoimportant.

MoredetailedinformationonSRMremovalandothermeatproductionissuescanbefoundinsubsequentchaptersinthiscoursemanual.

3.4. On-farm measuresClassicalcontrolmeasuresforinfectiousdiseases(biosecurity,quarantine,vaccination)donotgenerallyapplytoBSE.Givenallavailableevidence,theBSEagentisnottrans-mittedhorizontallybetweencattlebutonlythroughfeed,primarilyingestionofcontami-natedMBMduringcalfhood.WhenaBSEcaseisdetected,ithasbeenshownthatothercattlewithinthatherdareunlikelytotestpositiveforBSE,despitethelikelihoodthatmanycalvesofsimilaragetothecaseallconsumedthesamecontaminatedfeed.

However,someon-farmstrategies,primarilythosethatfocusonfeedasasourceofinfection,andsomecullingprogrammesdocontributetothecontrolanderadicationofBSE.Cullingstrategiesvaryamongcountries,andoftenchangeovertime.Somediffer-entcullingstrategiesthathavebeenappliedinclude(SSC,2000;2002c):

• theindexcaseonly• allcattleonthefarmwheretheindexcasewasdiagnosed• allcattleonthefarmwheretheindexcasewasbornandraised• allcattleontheindexcasefarmandonthefarmwheretheindex casewasbornandraised• allsusceptibleanimalsontheindexcasefarm (includingsheep,goatsandcats)• “feed-cohort“(cattlethatcouldhavebeenexposedto thesamefeedastheindexcase)• “birth-cohort“(allcattlebornoneyearbeforeoroneyear aftertheindexcaseandraisedonthesamefarm)

Whileherdcullingmaybeapoliticallyexpedientmeansofincreasingconsumercon-fidenceandfacilitatingexports,itisunlikelytobeanefficientriskmanagementmeas-ure (Heim and Murray, 2004). There are significant problems in implementing suchastrategy.Farmerssee itasaradicalapproachbecause it results inaconsiderablewasteofuninfectedanimals.Althoughtheremaybesufficientcompensationforculledanimals, farmersmaynotbelieve it is reasonable tocullapparentlyhealthy,produc-tiveanimals.Inadditiontheyarelikelytolosevaluablegeneticlinesand/ortheir“life’swork”.Forthesereasons,farmersmaybelesswillingtonotifysuspectcasesifcullingoftheirentireherdcouldresult.

Evidencefromanumberofcountriesindicatesthat,inthoseherdswheremorethanonecaseofBSEhasbeendetected,theadditionalcase(s)werebornwithinoneyearoftheindexcase.Asaresult,cullingabirthcohortisamorerationalriskmanagementstrategyasitfocusesonthoseanimalswithinaherdthathavethegreatestchanceof

Herdculling

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havingBSE.Evenso,dependingontheinitiallevelofexposureandtheoriginalsizeofthecohort,itislikelythatrelativelyfewadditionalcasesofBSEwillbedetectedinthebirthcohortofaherd indexcase.Cohortculling is,however, likely tobemuchmoreacceptabletofarmerswhencomparedwithherdculling.

3.�. Import controlThebestmeansofpreventingtheintroductionofBSEistocontroltheimportofcertainBSEriskproductsfromcountrieswithBSEorcountriesthatareatriskofhavingBSE.Mostcountriesdonotbanimportsofpotentiallyinfectivematerialsuntiltheexportingcountry has reported their first BSE case. This is usually too late, however, becausethe risk already existed before the first case was detected. Materials that should beconsideredriskyforimport(unlessappropriatesafetyconditionsaremet)includeanymammalianderivedmeals (includingMBMandotherproteinmeals), feedcontainingMBM,livecattleandoffal. Importofbeefandbeefproductsforhumanconsumption,including processed beef products, whole cattle carcasses and bone-in beef, shouldalsobecontrolled,especiallyfortheexclusionofSRM.Debonedbeefmeatisgenerallyconsideredasnon-riskyforimport.

3.�. EnforcementAlthough implementation of each measure decreases the overall risk of exposure,combining measures decreases the risk more profoundly (Heim and Kihm, 2003).Forexample,feedbansimplementedinconjunctionwithanSRMbanforfeedhaveastrongerimpact.Also,measuresmustbeeffectivelyimplementedandenforced.Simplyissuing a regulation or ordinance without providing the necessary infrastructure andcontrolswillnotachievethedesiredgoals.Educationofallpeopleinvolvedisrequiredatalllevelsandinallsectorsinordertoimproveunderstandingandcapacity,andthusimprovecompliance.

4. CLINICAL SIGNSIncontrasttomanyBSEcasespicturedinthemedia,mostcattlewithBSEhavesubtlesignsofdisease.Signsareprogressive,variableintypeandseverity,andmayincludedepression,abnormalbehaviour,weightloss,sensitivitytostimuli(light,sound,touch)andgaitormovementabnormalities.Othersigns thathavebeennoted insomeBSEcasesincludereducedmilkyield,bradycardiaandreducedruminalcontractions(Braunetal.,1997).

DifferentialdiagnosesforBSEincludebacterialandviralencephalitides(e.g.bornadisease, listeriosis, sporadic bovine encephalitis, rabies), brain edema, tumors, cer-ebrocortical-necrosis(CCN),cerebellaratrophy,metabolicdiseasesandintoxications,aswellasothercausesofweightlossandneurologicalabnormalities.

Becausenoneof theclinical signsarespecific (pathognomonic) for thedisease,adefinitive clinical diagnosis cannot be made. With experience, however, farmers andveterinarianscanbecomeefficientatearlyidentificationofBSEsuspects.Thesesuspi-cionsshouldalwaysbeconfirmedthroughlaboratorytesting.

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�. DIAGNOSIS OF BSE�.1. BiosafetyMicroorganisms are classified by the World Health Organization (WHO) accordingto their pathogenicity for humans and animals. According to this classification, pre-cautions must be taken when handling these agents primarily to protect the peoplehandling them,andalso toprotect thegeneralhumanpopulationand livestock fromaccidentalexposure.Dependingontheclassificationofthemicroorganism,precautionsmust also be taken to protect laboratory workers and the community from possibleexposureandinfection.Thus,WHOhasdefinedfourbiosafetylevel(BL)categoriesforlaboratories.ThesecategoriescorrelatesomewhatwiththeWHOriskgroupcategories,butalsoreflectwhatisbeingdonewiththemicroorganisminthelaboratory.

ThemostinternationallywellacceptedguidelineontheclassificationsystemforandthehandlingofmicroorganismsistheWHOLaboratorybiosafetymanual(WHO,2003).Thismanualdefinestheriskgroups,therequirementsforriskassessments,andtherequirementsforeachofthelaboratoryBLS.

In2000,theEUpublishedadirectivebasedontheWHOguidelines,whichdefinesanewriskgroupforBSEandrelatedanimalTSEsbasedonBSEagentcharacteristics(e.g.limitedriskforlaboratorypersonnelandthecommunity,inabilitytoexcludeaero-sol transmission). This new risk group is called 3**, which means risk group 3 withsomealleviations.Scrapie,ontheotherhand,isstillclassifiedasriskgroup2.

AccordingtotheSwissExpertCommitteeforBiosafety,differentbiosafetylevelsarerequiredwhenhandlingBSEmaterials,dependingonthetypeofmaterial(SwissExpertCommittee for Biosafety, 2006). For example, histology and Immunohistochemistry(IHC)onformicacid-inactivatedBSEmaterialcanbeperformedinaBL1laboratory,androutineBSEdiagnosticscanbeperformedinaBL2laboratorywithsomeadditionalmeasures.Areference laboratory forTSEmustbeBL3,butsomemodificationsareallowed.Attentionshouldbepaid to the fact thatBSE laboratory requirementsoftendifferamongcountries.

�.2. Sample collectionBecauseboththehighestconcentrationofPrPScandthemostprominentrelatedlesionstendtobelocatedintheareaoftheobexregionofthebrainstem(Figure4),samplingthisregionoptimizessensitivity,regardlessofthediagnostictestmethodused.Ifthisregionisnotsampledcorrectly,falsenegativeresultsmaybeobtained.Thisrequiresthatindividualscollectingsamplesarefamiliarwiththeanatomyofthisregion.

All animals clinically suspected of having BSE should be examined post mortem.Optimally,severalrepresentativeareasofthebrainofclinicalsuspectsareexamined;therefore,thewholeheadoftheanimalshouldberemovedandsenttothelaboratory.Thisalsoallowsteststobeperformedforotherdifferentialdiagnoses.Atthelabora-tory,thebrainisremovedassoonaspossibleforfurthertestingandonehalfisfixedinformalin(forhistopathologyandIHC).Theremaininghalfofthebrainisfirstsampledforrapidtestsandthenfrozenat-20°Cor-80°C.

Incasesofemergencyslaughter,fallenstockorroutinescreening,onlythecaudalbrainstem (medulla oblongata) is generally removed for testing, without opening theskull.Thecaudalendofthebrainstemshouldbevisiblethroughtheforamenmagnumafterseparationofthehead,andaspeciallydesignedspooncanbeusedtoremovethebrainstem(includingtheobexregion)throughtheforamen.Thebrainstemisthensplit

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longitudinally,andonehalffixedinformalinforhistopathologyandIHCwhiletheotherhalfisreservedandsampledforrapidtests.Thefreshtissueremainingaftersamplingforrapidtestsisthenfrozenat-20°Cor-80°C.

ForneuropathologyandIHC,tissueisfixedinformalin,inactivatedwithformicacid,andthenembeddedinparaffin.Theembeddedbrainsamplesaresectionedandplacedonglassslides.Forneuropathologicexamination,sectionsarethenstainedwithstand-ardhaematoxylinandeosin(H&E)stain.

�.3. Neuropathology and immunohistochemistryVisualizationof typicalneuropathologicchangesrequires that the tissuestructurebeintact.Thereforeitmaynotbepossibletoevaluateevenslightlyautolyticsamples(e.g.samplesfromfallenstockorcadavers,samplesimproperlyfixedfortransport).Freez-ingofsamplesalsodestroysthetissuestructure.

Aftercharacterizationofthehistopathologicfeaturespresentinasample,BSEmustbedifferentiatedfromotherneuraldiseasesshowingsimilarlesions.Theterm“spongi-form“ ispurelydescriptiveand issometimesused interchangeablywithother terms,suchasvacuolation,spongiosis,spongydegenerationormicrocavitation.Vacuolationoftheneuropilcanbeseeninmanydifferentdiseasesandeveninanormalbrain,sopos-siblecausesofspongiformchangesmustbedifferentiated(e.g.normalvacuolationvspathologicalvacuolationvsvacuolationfrompostmortemartifacts).“Encephalopathy”referstothefactthatthediseaseisprimarilydegenerativeand,apartfromgliosis,doesnotshowanyinflammatorychanges.

Afterneuropathologicexamination,IHCcanbeusedtoidentifyPrPScdirectly inthesamplebylabellingitwithspecificantibodies.Insomecases,IHCmayallowadefinitivediagnosisofBSEtobemadewhenquestionableorevennoneuropathologicchangesareseen.

However,becausethenormalPrPprotein(PrPC)present inthebraincellshasthesameaminoacidsequenceasPrPSc,antibodiesnormallyusedinIHCdetectbothPrPScandPrPC.Therefore,inordertobeabletodetermineifthereisanyPrPScpresent,the

FIGURE 4

Tissue selected for testing for BSE (histopathology and rapid tests), (s), includes the obex region (o)

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twoproteinsmustfirstbedifferentiated.ProteinaseKisanenzymethatcausestotalproteolysisofnormalPrPC,althoughPrPScisresistanttoproteolysisbyproteinaseKtoalargeextent.OnlysmallpartsatthebeginningandattheendofPrPScaredigestedand the remaining part, generally referred to as the core fragment or PrPRes, is stilldetectedbytheantibodies.Therefore,proteinaseKisusedinIHCtodigesttotallythePrPCpresentinthesample,ensuringthatanyPrPdetectedwillbePrPSc.Withoutthisstep,samplescouldyieldafalsepositiveresultowingtothedetectionofnormalPrPC.Similarly,incompletedigestioncouldleadtofalsepositiveresults.

Formostantibodiesusedintesting,therespectiveepitopeonPrPisnotaccessibleinthenativePrPconformation.Therefore,anadditionalsteptodemasktheappropriateepitopeonPrPres isrequired.Demaskingcanbeaccomplishedbydenaturationoftheproteinorbyusingnon-specificproteases.

�.4. Rapid BSE tests TestsareavailabletoanalyseBSEsuspectmaterialsrapidly(OIE,2005b).Whichrapidtestsare licensedandapproved invariouscountriesthroughout theworld isvariableandlistsareconstantlybeingupdated(EFSA,2006).

AllcurrentlylicensedBSErapidtestshaveseveralthingsincommon.First,theyusematerial from the brainstem, i.e. they are post mortem tests. Second, current rapidtestsarebasedonthesameprinciplesofhomogenization,proteinaseKdigestion(withthe exception of the IDEXX HerdChek BSE Antigen EIA) and detection. Although theprinciplesof thesestepsaresimilaramongtests, therearesignificantdifferences intheexecution.Thematerialsandproceduresarespecifictoeachtestsystemandtestperformance is validated under these specific conditions, thus protocols cannot bemodifiedorinterchangedamongtests.

Initially,thesampleofcentralnervoussystem(CNS)materialmustbehomogenizedwith a specific buffer containing stabilizers and detergents. After homogenization,proteinaseKisusedtodigestthePrPC(withtheexceptionoftheIDEXXHerdChekBSEAntigenEIA)andtheepitopeisdemasked.Then,theproteinaseKresistantfragmentofPrPSc,ifpresent,isdetectedwithspecificmonoclonalorpolyclonalantibodiesusingwesternblotorenzyme-linkedimmunosorbentassay(ELISA)technology.

Althoughtherearedifferencesbetweenthetests,theoverallperformance(sensitivityandspecificity)iscomparable.Greatdifferencescanbefoundinthehandlingandtheversatilityofthetestsforhighandlowthroughputlaboratoryset-ups.

�.�. New developmentsWorkisconstantlybeingdoneonthedevelopmentofnewrapidtests.Newtestsmaybebasedontherefinementofanestablishedprocedureoronthereplacementofproce-duresbycompletelynewconcepts.

Allnewtestsarestillbasedonpostmortemsamplingastheyusebrainmaterialfromtheobexregion.Ofcourse, theability todiagnoseBSEantemortemwouldbeahugeadvantage,andmuchresearchisbeingdoneinthisfield.Reportsonpossibleantemor-temtestsarepublishedregularly.However,noneofthesetestshassofarpassedthevali-dationprocess,andanimminentbreakthroughinantemortemtestingisnotforeseen.

DiagnosisofTSEsiscoveredindepth intheCapacityBuildingforSurveillanceandPreventionofBSEandOtherZoonoticDiseasesprojectcoursemanualDiagnostictech-niquesfortransmissiblespongiformencephalopathies(FAO,2007c).

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�. SURvEILLANCE SySTEmS�.1. Objectives of surveillance ThetwomajorobjectivesforBSEsurveillancearetodeterminewhetherBSEispresentinthecountryand,ifpresent,tomonitortheextentandevolutionoftheoutbreakovertime.Inthisway,theeffectivenessofcontrolmeasuresinplacecanbemonitoredandevaluated.However,thereportednumberofBSEcasesinacountrycanonlybeevaluat-edwithinthecontextofthequalityofthenationalsurveillancesystemandthemeasurestaken.BSEriskcanstillexistinacountry,evenifnocasesarefoundwithsurveillance.Surveillanceaimstosupplementthemorecomprehensivedatathatisprovidedbyariskassessment(HeimandMumford,2005).

Generalguidelinesfordiseasesurveillanceandspecificguidelinesforanappropri-ate levelofBSEsurveillancefor thedifferentcategoriesofnationalriskareprovidedintheOIETerrestrialAnimalHealthCode(OIE,2005c,d).TheserecommendationsareconsideredbyWTO(WTO,1994)andthe internationalcommunityasthe internationalstandards.

�.2. passive surveillanceInmostcountries,BSEislistedasanotifiabledisease,whichisabasicrequirementforafunctioningpassive(aswellasactive)surveillancesystem.However,somecountrieshavenonationalpassivesurveillancesystemforBSE,oronlyaweaksystem.

Until1999,BSEsurveillanceinallcountrieswaslimitedtothenotificationofclinicallysuspectedcasesbyfarmersandveterinarians(andothersinvolvedinhandlinganimals)totheveterinaryauthorities(passivesurveillance).Itwasassumedthatthiswouldallowearlydetectionofanoutbreak(HeimandWilesmith,2000).However,becausepassivesurveillancereliessolelyonthereportingofclinicalsuspectsandisdependentonmanyfactors,includingperceivedconsequencesonthefarmanddiagnosticcompetence,itisnotnecessarilyconsistentorreliable.Thus,althoughpassivesurveillanceisacrucialcomponent of any BSE surveillance system, it has become increasingly obvious thatpassivesurveillancealoneisnotsufficienttoestablishtherealBSEstatusofacoun-try.

Forapassivesystemtofunctioneffectively,severalfactorsmustbeinplace:veterinary structure:Thediseasemustbenotifiable.Case definition:A legaldefinitionofBSEmustexistandmustbebroadenoughto

includemostpositivecases.Disease awareness: The appropriate individuals (farmers, veterinarians) must be

abletorecognizeclinicalsignsofthedisease.willingness to report:Theremustbeminimalnegativeconsequencestotheidenti-

ficationofapositivecaseatthefarmlevelandmeasuresmustbeconsidered“reason-able”.

Compensation scheme: The costs of culled animals must be reasonably compen-sated.

Diagnostic capacity:Theremustbeadequatelaboratorycompetence.Becausethesefactorsvarygreatly,bothamongcountriesandwithincountriesover

time,theresultsofpassiveBSEsurveillancesystemsaresubjectiveandevaluationandcomparisonofreportednumbersofBSEcasesmustbemadecarefully.

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�.3. Active surveillanceTooptimizeidentificationofpositiveanimalsandimprovethesurveillancedata,thosepopulationsofcattlethatareatincreasedriskofhavingBSEshouldbeactivelytargetedwithinanationalsurveillancesystem.Withtheintroductionoftargetedsurveillanceofcattleriskpopulationsin2001,alargenumberofcountriesinEuropeandalsothefirstcountriesoutsideEuropedetectedtheirfirstBSEcases.

Cattlewithsignsofdiseasenon-specifictoBSEandcattlethatdiedorwerekilledforunknownreasonsmaybedefinedindifferentcountriesassickslaughter,emergencyslaughter,fallenstockordownercows.TheprobabilityofdetectingBSE-infectedcat-tleishigherinthesepopulations,asitmayhavebeenBSEthatledtothedebilitation,death,cullorslaughteroftheseanimals.ManyofthesecattlemayhaveexhibitedsomeoftheclinicalsignscompatiblewithBSE,whichwerenotrecognized.Theexperienceofmanycountriesinthelastyearshasshownthat,afterclinicalsuspects,thisisthesec-ondmostappropriatepopulationtotargetinordertodetectBSE.Targetedsurveillanceaimstosamplecattleintheseriskgroupsselectively,andtestingoftheseriskpopula-tionsisnowmandatoryinmostcountrieswithBSEsurveillancesystemsinplace.

Healthycattle => Routineslaughter

Cattlewithnon-specificsigns(e.g.weightloss,lossofproduction)and => Sick/emergencyslaughter,Cattlethatdiedforunknownreasons fallenstock,downercows(onthefarm,duringtransport)

CattlewithspecificsignsofBSE => BSEsuspects(orsuspicionofBSE)

Theageofthepopulationtestedisalsoimportant,astheepidemiologicaldatashowthatcattleyoungerthan30monthsrarelytestpositiveforBSE.Therefore,targetedsur-veillanceaimstosamplecattleover30monthsofageselectivelyintheriskpopulations,whichmaybeidentifiedonthefarm,duringtransportorattheslaughterhouse.

However,despite the fact that correctly implementedsamplingof riskpopulationswouldhypotheticallybesufficient toassessBSE inacountry, testingasubsampleofhealthyslaughteredcattleshouldbeconsidered.Thisisneededtominimizediversionofquestionablecarcassestoslaughter,i.e.toimprovecompliance.Iffarmersareawarethat randomsampling isoccurring,andwhen theprobabilityofbeing tested is largeenough,theyarelesslikelytosendsuspectanimalsdirectlytoslaughter.

Thespecificsurveillanceapproachesvaryamongthedifferentcountries.TheEUandSwitzerlandaretestingtheentireriskpopulationover24and30monthsofage,respec-tively.IntheEU,additionally,allcattlesubjecttonormalslaughterover30monthsofage are currently tested, whereas in Switzerland a random sample of approximately5%istested.CountriesoutsideEuropehaveimplementedavarietyofdifferenttestingsystems.FromtheexperiencesgainedinEurope,itisclearthatitismostefficienttoassuretheeffectiveimplementationofpassiveandtargetedsurveillanceinriskpopula-tionsratherthantofocusontestingtheentirenormalslaughterpopulation.

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miology,surveillance,andriskassessmentfortransmissiblespongiformencephalopa-thies(FAO,2007c).

�. RISK ASSESSmENT�.1. BSE status and international standardsFora longtime,BSEwasconsideredaproblemexclusivelyof theUK.Evenafter thedetectionofBSEcasesinseveralcountriesoutsidetheUK,theriskofhavingBSEwascategoricallydeniedbymanyothercountries.Onlyaftertheintroductionofactivesur-veillancedidseveral“BSE-free”countriesdetectBSE.

Before2005,theOIEdescribedfiveBSEcategoriesforcountries,butinMay2005anewBSEchapterwasadopted(OIE,2005e)reducingthenumberofBSEstatuscatego-riestothefollowingthree:

• Country,zoneorcompartmentwithanegligibleBSErisk• Country,zoneorcompartmentwithacontrolledBSErisk• Country,zoneorcompartmentwithanundeterminedBSErisk

According to the OIE, a primary determinant for establishing BSE risk status of acountry,zoneorcompartmentistheoutcomeofascience-basednationalriskassess-ment.Thisassessmentmaybequalitativeorquantitative,andshouldbebasedontheprinciplesgivenintheCodeChapters1.3.1and1.3.2onRiskAnalysisandtheAppendix3.8.5 on Risk Analysis for BSE (OIE, 2005f,g,h). The OIE Code Chapter on BSE (OIE,2005e) lists the followingpotential factors forBSEoccurrenceandtheirhistoricper-spectivethatmustbeconsideredinsuchanassessment:Releaseassessment1

• theTSEsituationinthecountry;• productionandimportofmeatandbonemeal(MBM)orgreaves;• importedliveanimals,animalfeedandfeedingredients;• importedproductsofruminantoriginforhumanconsumptionandforinvivouse

incattle.Inaddition,surveillanceforTSEsandotherepidemiologicalinvestigations(especially

surveillanceforBSEconductedonthecattlepopulation)shouldbetakenintoaccount.Exposureassessment:

• recyclingandamplificationoftheBSEagent;• the use of ruminant carcasses (including from fallen stock), by-products and

slaughterhousewaste,theparametersoftherenderingprocessesandthemeth-odsofanimalfeedmanufacture;

• thefeedingbansandcontrolsofcrosscontaminationandtheirimplementation;• thelevelofsurveillanceforBSEandtheresultsofthatsurveillance.

In addition to an assessment of BSE risk, the OIE status categorization for BSEincludesevaluationofsomeofthemeasuresinplaceinthecountry.AccordingtotheOIECode,factorsevaluatedintheestablishmentofBSEstatusshouldinclude:

• theoutcomeofariskassessment(asdescribedabove)• disease awareness programmes to encourage reporting of all cattle showing

clinicalsignsconsistentwithBSE;

2 In2006,theOIEBSEchapterwasmodifiedsothatonlyBSE,andnototherTSEs,isincludedintheexposureassessment.

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• compulsorynotificationandinvestigationofallcattleshowingclinicalsignscon-sistentwithBSE;

• examinationinanapprovedlaboratoryofbrainsamplesfromthesurveillanceandmonitoringsystem

�.2. The geographical BSE risk assessmentThegeographicalBSEriskassessment(GBR)isaBSEriskassessmenttooldevelopedby theScientificSteeringCommitteeof theEuropeanCommissionandbasedonOIEassessmentcriteria.TheGBRisaqualitativeindicatorofthelikelihoodofthepresenceofoneormorecattlebeinginfectedwithBSE,atagivenpointintimeinacountry,andhasbeenappliedtoanumberofcountriesthroughouttheworld.Themethodisaquali-tativeriskassessment,whichusesinformationonriskfactorsthatcontributeeithertothepotentialforintroductionofBSEintoacountryorregionortotheopportunityforrecyclingof theBSEagent inacountryorregion.The followingquestions,relatedtoreleaseandexposure,areansweredthroughtheGBR:

• Wastheagentintroducedintothecountrybyimportofpotentiallyinfectedcattleorfeed(MBM),andifsotowhatextent?

• Whatwouldhappeniftheagentwereintroducedintotheanimalproductionsys-tem,i.e.woulditbeamplifiedoreliminated?

Beforethedetectionofthefirstcasesinmany“BSE-free”countries,theGBRshowedthatariskcouldbepresent.Thisconfirmedtheconceptthataserious,comprehensiverisk assessment must be carried out to estimate the extent of the BSE problem incountries.

Thus, decisions on preventive measures should be based on such a detailed riskassessment, whether it is the GBR or another science-based assessment based onOIErecommendations.Nocountryshouldwaituntilthefirstcaseoccursbeforetakingpreventivemeasures.ThereremainmanycountrieswithanunknownBSErisk.Inordertominimizeimportrisksfromthesecountries,furtherriskassessmentsareneededtoevaluatetherealBSEdistributionworldwide.

Riskassessment forTSEs iscovered indepth in theCapacityBuilding forSurveil-lance and Prevention of BSE and Other Zoonotic Diseases project course manualentitledEpidemiology,surveillance,andriskassessmentfortransmissiblespongiformencephalopathies(FAO,2007).

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bovine spongiform encephalopathy (BSE). Schweiz Arch Tierheilk 139: 35-41 http://www.bse.

unizh.ch/english/examination/htmlsklinischer.htm

DEFRA (Department for Environment Food and Rural Affairs). 2004a. BSE pages. http://www.

defra.gov.uk/animalh/bse/index.html

Detwiler LA, Baylis m.2003.Theepidemiologyofscrapie.RevScitechOffintEpiz22(1),121-143

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Bencsik A, Biacabe AG, Beringue v, Laude H, Le Dur A, vilotte JL, Comoy E, Deslys Jp, Grassi

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European Commission. 2004. Food and Feed Safety: Legislation concerning TSE. http://europa.

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European Food Safety Authority.2006.EFSAScientificReportsontheevaluationofBSE/TSEtests.

http://www.efsa.eu.int/science/tse_assessments/bse_tse/catindex_de.html

FAO.2007a.ManualfortheCourse:Managementoftransmissiblespongiformencephalopathiesin

livestockfeedsandfeeding.CapacityBuildingforSurveillanceandPreventionofBSEandOtherZoonoticDiseases.

FAO. 2007b. Manual for the Course: Diagnostic Techniques for TSEs. Capacity Building forSurveillanceandPreventionofBSEandOtherZoonoticDiseases.

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Heim D, Kihm U. 1999. Bovine spongiform encephalopathy in Switzerland - the past and the

present.RevScitechOffintEpiz18(1):135-144

Heim D, Kihm U. 2003. Risk management of transmissible spongiform encephalopathies in

Europe.RevScitechOffintEpiz22(1),179-199

Heim D, mumford E.2005.ThefutureofBSEfromtheglobalperspective.MeatScience70:555-562

Heim D, murray N.2004.Possibilities tomanage theBSEepidemic:cohortcullingversusherd

culling–experiencesinSwitzerland.In:Prions:achallengeforscience,medicineandthepublichealthsystem,2nded.EdsHFRabaneau,JCinatl,HWDoerr.Karger,Basel,Switzerland.pp

186-192

Heim D, wilesmith J.w.2000.SurveillanceofBSE.ArchVirolSuppl.16,127-133

Lasmezas CI. 2003. The transmissible spongiform encephalopathies. Rev Sci tech Off int Epiz

22(1),23-36

OIE (world Organisation for Animal Health).2005a.Proceduresforthereductionofinfectivityof

transmissible spongiform encephalopathy agents. Terrestrial Animal Health Code, Appendix

3.6.3.http://www.oie.int/eng/normes/mcode/en_chapitre_3.6.3.htm

OIE. 2005b. Bovine Spongiform Encephalopathy. Manual of Standards for Diagnostic Tests andVaccines,Chapter2.3.13.http://www.oie.int/eng/normes/mmanual/A_00064.htm

OIE. 2005c, General Guidelines for Animal Health Surveillance. Terrestrial Animal Health CodeAppendix3.8.1.http://www.oie.int/eng/normes/MCode/en_chapitre_3.8.1.htm

OIE.2005d.SurveillanceforBovineSpongiformEncephalopathy.TerrestrialAnimalHealthCode,Appendix3.8.4.http://www.oie.int/eng/normes/MCode/en_chapitre_3.8.4.htm

OIE. 2005e.Bovinespongiformencephalopathy.TerrestrialAnimalHealthCode,Chapter2.3.13.

http://www.oie.int/eng/normes/MCode/en_chapitre_2.3.13.htm

OIE.2005f.GeneralConsiderations(RiskAnalysis).TerrestrialAnimalHealthCode,Chapter1.3.1.

http://www.oie.int/eng/normes/MCode/en_chapitre_1.3.1.htm

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int/eng/normes/MCode/en_chapitre_1.3.2.htm

OIE. 2005h. Factors to consider in conducting the bovine spongiform encephalopathy risk

assessment recommended inchapter2.3.13.TerrestrialAnimalHealthCode,Appendix3.8.5.http://www.oie.int/eng/normes/MCode/en_chapitre_3.8.5.htm

prince mJ, Bailey JA, Barrowman pR, Bishop KJ, Campbell GR, wood Jm.2003.Bovinespongiform

encephalopathy.RevScitechnOffintEpiz22(1),37-60

Schreuder BE, Somerville RA.2003.Bovinespongiformencephalopathy insheep?RevSci techOffintEpiz22(1),103-120

SSC (Scientific Steering Committee of the EC).2000.OpinionoftheScientificSteeringCommittee

onBSE-relatedcullingincattle.Adoptedatthemeetingof14/15September2000.http://europa.

eu.int/comm/food/fs/sc/ssc/out138_en.pdf

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spongiform

encephalopathies

SSC.2001a.OpiniononhypothesesontheoriginandtransmissionofBSE.AdoptedbytheScientific

SteeringCommitteeatitsmeetingof29-30November2001.http://europa.eu.int/comm/food/fs/

sc/ssc/out236_en.pdf

SSC. 2001b. Opinion on the six BARB BSE cases in the UK since 1 August 1996. http://europa.


SSC.2001c.SafetyofmilkwithregardtoTSE:Stateofaffairs.http://europa.eu.int/comm/food/fs/

sc/ssc/out175_en.html

SSC.2002a.Thesafetyofbovineembryos.AmendmenttotheSSCopinionof18-19March1999on

thepossiblevertical transmissionofBovineSpongiformEncephalopathy (BSE).http://europa.


SSC. 2002b. Opinion on TSE infectivity distribution in ruminant tissues (state of knowledge,

December2001).AdoptedbytheScientificSteeringCommitteeatitsmeetingof10-11January

2002.http://europa.eu.int/comm/food/fs/sc/ssc/out241_en.pdf

SSC. 2002c. Update of the opinion on TSE infectivity distribution in ruminant tissues. Initially

adoptedbytheScientificSteeringCommitteeatitsmeetingof10-11January2002andamended

atitsmeetingof7-8November2002.http://europa.eu.int/comm/food/fs/sc/ssc/out296_en.pdf

SSC.2002d.OpinionoftheSSContheadditionalsafeguardprovidedbydifferentcullingschemes

under the current conditions in the UK and DE. Adopted on 11 January 2002. http://europa.


Swiss Expert Committee for Biosafety. 2006. http://www.umwelt-schweiz.ch/buwal/eng/

fachgebiete/fg_efbs/index.html

TAFS (International Forum for TSE and Food Safety).2004a.TAFSpositionpaperonspecifiedrisk

materials. http://www.tseandfoodsafety.org/position_papers/TAFS_POSITION_PAPER_SPECIFI

ED%20RISK%20MATERIALS.pdf

TAFS.2004b.TAFSpositionpaperontestingofcattleforBSE–Purposeandeffectiveness.http://

www.tseandfoodsafety.org/position_papers/TAFS_POSITION_PAPER_ON%20TESTING%20OF%

20CATTLE.pdf

TAFS.2007.TAFSpositionpaperon thesafetyofbovinemilkandbovinemilkproducts”.http://

www.tseandfoodsafety.org/position_papers/TAFS_POSITION_PAPER_ON_MILK.pdf

Taylor Dm, Fraser H, mcConnell I, Brown DA, Brown KL, Lamza KA, Smith GRA. 1994.

Decontamination studies with the agents of bovine spongiform encephalopathy and scrapie.

ArchVirol139,313–326

Taylor Dm, woodgate SL.1997.Bovinespongiformencephalopathy:thecausalroleofruminant-

derivedproteinincattlediets.RevScitechOffintEpiz16,187–198

Taylor Dm, woodgate SL.2003.Renderingpracticesandinactivationoftransmissiblespongiform

encephalopathyagents.RevScitechOffintEpiz22(1),297-310

United Kingdom Department of Health. 2006. CJD-homepage. http://www.dh.gov.uk/

PolicyAndGuidance/HealthAndSocialCareTopics/CJD/fs/en

wells GA, Scott AC, Johnson CT, Gunning RF, Hancock RD, Jeffrey m, Dawson m, Bradley R.1987.

Anovelprogressivespongiformencephalopathyincattle.VetRec121(18),419-420

wells GAH, Dawson m, Hawkins SAC, Green RB, Dexter I, Francis mE, Simmons mm, Austin AR,

Horigan mw. 1994. Infectivity in the ileum of cattle challenged orally with bovine spongiform

encephalopathy.VetRec135(2),40-41

wells GAH, Dawson m, Hawkins SAC, Austin AR, Green RB, Dexter I, Horigan mw, Simmons

mm. 1996. Preliminary observations on the pathogenesis of experimental bovine spongiform

encephalopathy. In: Bovine spongiform encephalopathy: The BSE Dilemma. Ed. C.J. Gibbs,

SeronoSymposia,Norwell,USASpringer-Verlag,NewYork,Inc.pp.28-44

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wells GA, Hawkins SA, Green RB, Austin AR, Dexter I, Spencer yI, Chaplin mJ, Stack mJ, Dawson

m. 1998. Preliminary observations on the pathogenesis of experimental bovine spongiform

encephalopathy(BSE):anupdate.VetRec142(5),103-106

wells GA, Hawkins SA, Green RB, Spencer yI, Dexter I, Dawson m. 1999. Limited detection

of sternal bone marrow infectivity in the clinical phase of experimental bovine spongiform

encephalopathy(BSE).VetRec144(11),292-294

wells GA.2003.PathogenesisofBSE.VetResCommun.Suppl1,25-28

wilesmith Jw, wells GA, Cranwell mp, Ryan JB. 1988. Bovine spongiform encephalopathy:

epidemiologicalstudies.VetRec123(25),638-644

wilesmith Jw, Ryan JB, Atkinson mJ.1991.Bovinespongiformencephalopathy:epidemiological

studiesontheorigin.VetRec128(9),199-203

will RG, Ironside Jw, Zeidler m, Cousens SN, Estibeiro K, Alperovitch A, posers S, pocchiari m,

Hofman A, Smith pG.1996.AnewvariantofCreutzfeldt-JakobdiseaseintheUK.Lancet347,

921–925

world Health Organization. 2003. Laboratory Biosafety Manual. Second Edition (Revised).

ReferencenumberWHO/CDS/CSR/LYO/2003.4.http://www.who.int/csr/resources/publications/

biosafety/Labbiosafety.pdf

wrathall AE.1997.Risksoftransmittingscrapieandbovinespongiformencephalopathybysemen

andembryos.RevSciTechOffintEpiz16(1),240-264

wrathall AE, Brown KF, Sayers AR, wells GA, Simmons mm, Farrelly SS, Bellerby p, Squirrell

J, Spencer yI, wells m, Stack mJ, Bastiman B, pullar D, Scatcherd J, Heasman L, parker J,

Hannam DA, Helliwell Dw, Chree A, Fraser H. 2002. Studies of embryo transfer from cattle

clinicallyaffectedbybovinespongiformencephalopathy(BSE).VetRec150(12),365-378

wTO (world Trade Organization).1994.AgreementonSanitaryandPhytosanitaryMeasures.FinalActoftheUruguayRound,Article5.http://www.wto.org/english/docs_e/legal_e/15-sps.pdf

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Implementation of

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OvERvIEw: ImpLEmENTATION OF TRANSmISSIBLE SpONGIFORm ENCEpHALOpATHIES mEASURES IN mEAT pRODUCTION

1. GENERAL CONCEpTSThegoalofanationalBSEcontrolprogrammeistominimizeexposureofhumansandanimalstotheBSEagent.ExperienceinEuropeandelsewherehasshownthatacom-plementarysystemofintegratedmeasuresmustbeeffectivelyimplementedtoensurethatthisgoalismet(HeimandKihm,2003).Exactlywhichmeasuresareimplementedina country shoulddependprimarilyonnationalBSE riskasdeterminedbya com-prehensive national BSE risk assessment, as well as economics, trade and capacityavailabletoenforcethemeasureseffectively(HeimandMumford,2005).Insomecases,morerestrictivemeasuresmaybemoresimpletoenforce,andthereforemaybemoreeconomically justifiable, but all measures ultimately aim to prevent the exposure ofhumansandanimalstotheBSEagent.

Measuresmustbeappliedfromfeedproductionandthefeedingofanimalsonthefarm, to the identificationofallpotentially illanimals, tosafeslaughteringandmeatprocessingpractices;i.e.“fromstabletotable.”Moreover,restrictionsonimportsmustbe considered, to prevent entry or re-entry of infective material in exposed animals,feedsforanimalsandfoodsforhumans.Becauseriskisnotlimitedtoexportingcoun-tries thathavereportedBSEcases, importingcountriesmustnotonlyevaluate theirdomesticrisk,butalsotheriskposedbyany importsofpotentiallyriskyproducts. Inordertobeeffectiveatreducingrisk,allimplementedmeasuresmustbecontrolledandenforcedthroughasystemofself-regulation,controlsandauditsintegratedatmultiplestepsalong theproductionchain.Finally, educationanddiseaseawarenessmustbepromotedinordertopromotecompliancewiththemeasuresalongthefeedproductionchain,includingatthefarmlevel.

2. CONTROL ON THE FARm It iswellacceptedthatcattlecanbeexposedtotheBSEagentthroughtheingestionof contaminated feed. Generally, this is feed containing meat and bone meal (MBM)derivedfromruminants.Therefore,akeymeasureinpreventingthespreadandrecy-clingoftheBSEagentistopreventruminant-derivedmaterialfrombeingfedtorumi-nantsthroughimplementationandenforcementofafeedban.Thiscontrolmustbeginwiththeappropriaterenderingofanimalby-productsandmanufacturingoffeeds,andmustcontinuethroughthefarmleveltoensurethatthenationalfeedbaniscompliedwith.MeasuresassociatedwithfeedmanufacturingarecoveredindepthintheCapacityBuilding forSurveillanceandPreventionofBSEandOtherZoonoticDiseasesprojectcoursemanualentitledManagementoftransmissiblespongiformencephalopathiesinlivestockfeedsandfeeding(FAO,2007).

ThepossibilityofidentifyingindividualanimalsandtrackingthemthroughslaughterandprocessingisimportantnotonlytocontrolofTSEsbutforfoodsafetyingeneral.The farmofbirth (ororigination) is the logicalplace for identification tobe initiated.

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Optimally,anationalsystemwouldexistforuniqueidentificationofallanimals.Inaddition,itisimportantthatanimalsillwithTSEsandotherdiseasesberecognized

andremovedpriortogoingtoslaughter.Optimally,thisoccursatthefarmlevel,whichrequiresgooddiseaseawarenessandeducationofbothanimalownersandveterinar-ians.TheanimalownersmustalsobewillingtoreportTSEsuspects.Thewillingnesstoreportisdirectlyrelatedtotheconsequencesofreporting.IftheofficialTSEcontrolprogrammeisseenasunfairor toorestrictiveor isnotadequatelycommunicatedtotheanimalowners,or if compensation for culledanimals is inadequate, thediseasewillnotbereported.

3. CONTROL AT THE SLAUGHTERHOUSE AND pROCESSING pLANT ControlmeasuresforTSEsintheproductionofmeatandmeatproductsmustspecifi-callyaddressthefollowingpointsattheslaughterandprocessinglevels:

Slaughterlevel:• Pre-slaughterinspection• Appropriatestunningprocedures• Appropriatehideandheadremovalprocedures• Properremovalandhandlingofspecifiedriskmaterials(SRM)(includingcarcass

inspection)• Controlofcrosscontamination

Processinglevel:• Traceability• ControlofSRMinfurtherprocessing

Specified risk materials (SRM) are those animal tissues most likely to contain TSEinfectivity,includingbovinefallenstock.Therefore,SRMshouldbeexcludednotonlyfromthehumanfoodchain,butalsofromthefeedchain(atminimumforruminantspecies).RenderingofSRM,evenatthestandardprocessingparametersof133ºCand3barsofpressure for 20 minutes, does not entirely inactivate the agent (Taylor and Woodgate,2003).ThereforeseparationandsubsequentdestructionofallSRMatslaughteristhemosteffectivemethodforminimizingtherecyclingofBSEinfectivityandtherebysub-stantiallyreducingtheriskofintentionalorinadvertentexposureofruminants.Controlsattheslaughterhouse(aswellasattherenderingplantinthecaseoffallenstock)mustbeinplacetoensuretheappropriateseparationanddisposaloftheriskmaterial.

Thepossibilityof tracingproductsback to theslaughterhouse,oroptimally, to thefarmoforigin,isanimportantconceptforassuringfoodsafety.

4. CONTROL OF CATTLE NOT FIT FOR NORmAL SLAUGHTER After clinical BSE suspects, cattle showing non-specific signs of disease (signs forwhichnocleardiagnosisispossible)arethemostlikelytobeBSEpositive.Therefore,removalanddisposalofthesecattlepriortoenteringtheslaughterlinereducestheriskofcontaminationoftheslaughterhouseand,asabove,minimizestherecyclingofBSEinfectivity,therebyreducingtheriskofintentionalorinadvertentexposureofruminants.Asforsuspects,identificationoftheseriskanimalsatthefarm,duringsaleortransportandattheslaughterhouserequiresgooddiseaseawarenessaswellasaprogrammeofreasonablemeasuresforcompensation.

Thesebasicconceptsaredevelopedinfurtherdetailinthefollowingcoursemanual

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chapters, inparallelwithcurrentgeneralpracticesformanagementofanimals fromthefarmthroughtheslaughterhouse,andofbovineproductsthroughprocessing.

�. REFERENCESFAO. 2007. Management of transmissible spongiform encephalopathies in livestock feeds and

feeding.Coursemanual,ProjectCapacityBuildingforSurveillanceandPreventionofBSEandOtherZoonoticDiseases.Rome


Europe.RevscitechOffintEpiz22(1),179-199

Heim D, mumford E.2005.ThefutureofBSEfromtheglobalperspective.MeatScience70:555-

562

Taylor Dm, woodgate SL.2003.Renderingpracticesandinactivationoftransmissiblespongiform

encephalopathyagents.RevScitechOffintEpiz22(1),297-310

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Regulations and

standards for the

meat industry

REGULATIONS AND STANDARDS FOR THE mEAT INDUSTRy

1. GENERAL CONCEpTSThe appearance of TSEs has presented new public and animal health challenges tocountriesthroughouttheworld. Internationalrecommendationsandregulationshavebeen developed both to improve public and animal health and facilitate fair tradethroughthestandardizationofmeasurestocontrolandpreventTSEs,andBSEinpar-ticular, acrosscountriesand regions.TheWorldTradeOrganization (WTO)considersthestandardssetandrecommendationsmadebytwointernationalbodies,theCodexAlimentariusCommission(oftheWorldHealthOrganization[WHO]andFAO)forfeedsand food and the World Organisation for Animal Health (OIE) for animal health andzoonoses,tobetheofficialinternationalstandards(WTO,1994).

Many countries have implemented some national measures, based on the inter-national standards, in order both to protect domestic public and animal health andmaintaintradeinanimalsandanimalproducts.Standardsandrequirementsarealsosetbygroupsofcountries(e.g.theEuropeanUnion/[EU]),independentstandardsettingorganizations, and international regional, and national industry groups and partner-ships.

Tohelpcountriesandindividualagriculturaloperationseffectivelyimplementthevar-iousstandardsinplace,practiceguidelinesandcodesofpracticehavebeendeveloped.Forexample,goodmanufacturingpractices(GMPs)aregivenbytheCodexAlimentariusforslaughterandprocessing.

2. THE pLAyERS: wHO SETS THE STANDARDS?2.1. International standardsOfficially,accordingtoWTO,standardsforanimalimportandformanagementfromthefarmtotheslaughterhousehavebeentheresponsibilityofOIEandstandardswithintheslaughterhousethroughretailfoods(includingimportoffoods)havebeentherespon-sibility of FAO. Recently, OIE and FAO have also begun to work jointly on food safetyissueswithinthe“stabletotable”concept.AllinternationalstandardsarebasedontherecommendationthatmeasuresbeappliedbasedontheoutcomeofanationalBSEriskassessment(OIE,2005a,WTO,1994).Countriesthendeveloptheirownlegislationbasedontheseguidelinesandtheirownrisk,needsandgoals.

The Codex Alimentarius In1963,theCodexAlimentariusCommissionwascreatedbyWHOandFAOtodevelopfoodstandards,guidelinesandrelatedtextssuchascodesofpractice.Themainpur-posesaretoprotectthehealthofconsumers,toensurefairtradepracticesinthefoodindustryandtopromotecoordinationofallfoodstandardsworkundertakenbyinterna-tionalgovernmentalandnon-governmentalorganizations.TheoutputfromtheCodexCommissioniscalledtheCodexAlimentarius(hereafterreferredtoas“Codex”),whichcomprehensively describes basic principles of food hygiene (www.codexalimentarius.

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net).Codexistheinternationallyrecognizedminimumstandardforfoodproductionandproducts(CodexAlimentarius,2006).

In addition to providing technical standards for products, the Codex also providesrecommendedcodesofpractice.Thesearerecommendations for“goodmanufactur-ingpractices”andsafe foodproduction.Generalprinciplesof foodhygienearegiveninCAC/RCP1,whichincludesthegloballyrecognizedrecommendationfortheset-upand implementation of HACCP systems (HACCP is described in the “Quality controlconcepts,hygieneandHACCPinthemeatindustry”chapterofthiscoursemanual).TherecommendedinternationalcodeofhygienepracticeforfreshmeatisgiveninCAC/RCP011,whichappliestofreshmeatintendedforhumanconsumption.ThisCodecontainsminimum requirements of meat hygiene up to and including the transport of meat,includingrecommendationsandprinciplesfor:

• hygienicpracticesduringanimalproductionandtransportofanimalstoslaughter;• availabilityofinformationonhazardsthatmaybepresentinslaughteranimals;• hygienic facilities and equipment for holding, slaughter, dressing and further

processing,storageanddistribution;• hygienicpracticesduringholding,slaughter,processing,storageanddistribution;• provisionofadequatefacilitiesforinspectionactivities.

Requirements for ante mortem and post mortem inspection of slaughter animalsand for ante mortem and post mortem judgement of slaughter animals are given inCAC/RCP041,whichshouldbeconsideredinconjunctionwithCAC/RCP011.

RequirementsprovidedbytheCodexarecontinuallybeingupdatedforeachcommod-itycategory.ThemostrecentofficialversionsarepublishedontheWebsite.

Terrestrial Animal Health Code of the world Organisation for Animal Health OIE,(www.oie.int)isanintergovernmentalorganizationrepresenting167membercoun-tries.TheOIEcollects,analysesandmakesavailablethelatestscientificinformationonanimaldiseasesanddiseasecontrolthroughouttheworld.Scientificstandardsarethendevelopedbasedonthisinformation.Thestandardsarepreparedbyelectedspecialistcommissions and working groups comprised of internationally-renowned scientists,mostofwhomareexpertsfromwithinthenetworkof156OIEcollaboratingcentresandreferencelaboratoriesthatalsocontributetowardsthescientificobjectivesoftheOIE.Afteradoption,thestandardsaremadeavailableastheTerrestrialAnimalHealthCode(OIECode;OIE,2005b)andtheManualofdiagnostictestsandvaccinesforterrestrialanimals(OIE,2005c).Similarstandardsareavailableforaquaticspecies.

TheOIEsetsstandardsforanimalhealthissuesandzoonoses,andprovidesspecificinformation on BSE (OIE, 2005d), as well as recommendations on what products aresafetotradeunderwhatconditions(OIE,2005a).AnoverridingconceptintheOIECodeisthatmeasuresmustbeappliedbasedontheoutcomeofariskassessment.

International Organization for StandardizationTheInternationalOrganizationforStandardization(ISO;www.iso.org)isannongovern-mentalorganizationmadeupofarepresentativeofthenationalstandardsinstitutesineachof153countriesandacoordinatingSecretariat inGeneva,Switzerland.The ISOdelegatesarenotrepresentativesofthegovernmentsbutmayrepresentnationalgov-ernmentalorganizationsortheprivatesector.Thus,theISOcanalignrequirementsofallstakeholdersincludingsuppliers,users,government,industryandconsumersinan

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efforttopromotetheconceptsoftheWTOTechnicalBarrierstoTrade(TBT)Agreement.The ISOholdsobserverstatus in theWTO,andpublishesadirectoryofallstandard-izingbodiesintheworldthathaveacceptedtheWTOTBTStandardsCode(ISO,2006)onbehalfoftheWTO.IthascollaborativerelationshipswithseveralUNorganizations,includingtheCodexCommission.

TheISOdevelopsuniformcriteriatobeappliedtoallareasofproductionofavari-etyofproducts, including foodproducts.Standardsaredevelopedbyconsensus.Thestandardsarewidelyappliedandareinsomecasesacceptedbyofficialstandardsettingorganizationssuchasnationalgovernments.

ThelateststandardsforcontrolofsafefoodsaregiveninISO22000:2005,developedbyworkinggroupsspecialized in foodsafety.Thisstandard is forcertificationof foodsafetysystemsandcoversthewholesupplychainfromstabletotable(Figure1).Italsocoversallperipheralaspectsofthefoodsupplychainsuchasfeed,veterinarydrugs,packagingandtransport.

European Committee for StandardizationTheEuropeanCommitteeforStandardization(CEN,www.cenorm.be)isanon-govern-mentalorganizationthatistheEuropeancounterparttoISO.Itincludesalltheregional

FIGURE 1

The scope of the ISO 22000:200� includes the entire food supply chain

ThescopeoftheISO22000:2005includestheentirefoodsupplychain(withinthedottedlineinthefigure).Communication throughout the food chain, including consumers, third party suppliers and supervisingauthorities,isemphasizedtoensureidentificationandcontrolofallfoodsafetyhazards.Theschemeshowstheinteractionbetweenthemanystepsofthesupplychain,includingotherproductsandinstitutionsthatarenotdirectlyconsideredfoodordonotproducefood,butwhichmayhaveanimpactonthesafetyoffood.Source: Modified from ISO 22000, available at http://www.iso.org/iso/en/commcentre/pressreleases/archives/2005/Ref966.html

Producer of pesticides, fertilizers

and veterinary drugs

Supply chain for the production of ingredients and additives

Transport and storage

Producers for machinery and installations

Producers of cleaning and disinfecting agents

Producers of packaging material

Service companies

Consumers

Supe

rvis

ing

auth

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es

Primary production

Feed production

Food production

Further production

Distribution

Retailer, gastronomy and catering

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standardization bodies of Europe, who send balanced delegations to the CEN policymakingbodies,technicalcommitteesandworkinggroups.Otherinterestedstakehold-ers (associate members, counsellors, European trade federations and internationalorganizations)maytakepartindevelopingstandards,dependingonthespecifictermsofreferenceofthework.TheCENalsoworkswithotherEuropeanbodiesandinterna-tionalbodies.

Standards are adopted according to a weighted majority vote of the CEN NationalMembers.Thestandardsarebindingtoallmembercountries,whichmustimplementthestandardsatnationallevelandwithdrawanyconflictingstandards.

2.2. National standards National standards are those set by individual governments of countries or groupsof countries,whichbilateral tradingpartnersare required tomeet in order to trade.Because of the variability in and frequent modifications to national standards, it isimportant that exporters understand the most current regulations in the country ofdestination of their food products. These can often be found on the Web site of theresponsibledepartment,butallthecurrentrequirementsforaspecificcommoditymaybedifficulttodetermine.

Intermsofglobalimpactontrade,therearetwomainregulatoryblocks(theEUandtheUSA),eachhavingtheirownstandards.WithinEurope,theEuropeanCommitteeforStandardizationalsoprovidesstandards.BoththeEUandUSAtrytomaintainextremelyhighnationalsanitarysecuritythroughstrictregulationsofimportedgoods.Thus,thestandardssetbytheEUandtheUSA,aswellasthoseofothertradingpartners,canhavemajorimpactsoncountrieswishingtoexport.

However,inordertoprotectnationalanimalandhumanhealthwhileoptimizingtheability of countries to trade, the WTO requires that all national standards (includingthoseof theEUandUSA)bebasedontheoutcomeofariskassessment, if theyaremorestrictthantheinternationalstandards.Theriskassessmentmustbescientificallybased,and take intoaccount thediseasestatus in thecountryand theactualriskofimportingadiseasethroughtrade.

Regulations of the European Union The25countries(memberstates)oftheEUareunitedunderauniformsystemofregu-lationsandlaws,aswellasacommonsinglemarket,asinglecurrency(adoptedby12outof25memberstates),andasingleagriculturalpolicy.

WithintheEU,comprehensiveregulationshavebeenputinplacetoprovideforthecontrolandeventualeradicationofBSE.SpecificregulationscanbefoundontheEUWebsite(EU,2006a).Theseregulationsaffectnotonlythemembercountries,butalsoaffectthirdcountries(countriesoutsidetheEU)intheiractionsandtradewiththeEU.Individual EU states may have their own rules for implementation, but all must ulti-matelycomplywiththeEUregulations.

Inaddition,theEUregulationsmustbeconsideredbycountrieslookingtowardsEUaccessionorwishing toexpand theiropportunities for trade.TheEU regulationsarethereforebeingadopted,asawholeorinprinciple,bymanyothercountriesthroughouttheworld.Consequently,bansandothermeasuresimplementedbytheEUcontinuetoinfluencetheworldmarketinanimalsandanimalproducts.

TheEUregulationsarecontinuallybeingupdated,and itcanbedifficult toextract

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the most current and relevant information. Many specific decisions are no longer inforce,andtherelevantregulationshavebeen incorporated intoothercurrent legisla-tion. However, updated summaries of new information on BSE topics are available,andcurrentlegislationonfoodhygieneandhygieneoffoodofanimaloriginincludingslaughtering,boningandfurtherprocessingaswellas inspectionandofficialcontrolisavailable.UpdatesongeneralquestionsoffoodsafetyandconsumerhealthcanbeobtainedonthefoodsafetyWebsiteoftheDirectorate-GeneralHealthandConsumerProtection(EU,2006b).

TheEUhasconsolidatedmostof theiranimalby-products legislation into the textof Regulation 1774/2002 (EU, 2002), which categorizes animal by-products (animalcarcases,partsofanimalcarcasesandproductsofanimaloriginthatarenotintendedfor human consumption) according to risk, and controls their use and disposal. Thisregulationisdiscussedindetailinthe“Renderingofanimalby-products”chapterintheCapacityBuildingforSurveillanceandPreventionofBSEandOtherZoonoticDiseasesprojectcoursemanualentitledManagementoftransmissiblespongiformencephalopa-thiesinlivestockfeedsandfeeding(FAO,2007).

Animalwelfare (important in thecontextofmeatproductionandslaughtering) isasubjectofconcernforEuropeanconsumers,andisalsocoveredbyEUregulations.TheEUanimalwelfareregulations(EU,2006c)arebasedupontheEuropeanConventionfortheProtectionofAnimals.ThepurposeofthisConvention,signedundertheauspicesoftheCouncilofEurope,istolaydownminimumcommonstandardsfortheprotectionofanimalskeptforfarmingpurposes.Thestandardsrequirememberstatestoensurethattheownersorkeepersofanimalslookafterthewelfareoftheiranimalsandseethattheyarenotcausedanyunnecessarypain,sufferingor injury.Thestandardsaredevelopedbasedonpastexperienceandpresentscientificknowledge.

TheEUalsohasrulesfortheprotectionofanimalsduringtransport,whichsafeguardanimalwelfareduringtransporttothemarketandtotheslaughterhouse.Theserulesidentify all theparties involved in transportandsetout their respective responsibili-ties,strengthenmonitoring,andprovideforstricterregulationoflongjourneysandthevehiclesused.

TheEuropeanConventionalsoappliestothemovement,lairaging,restraint,stunning(restraintandstunningarecompulsorywithoutexception)andactualslaughter,includ-ing inthecaseofritualslaughter,ofdomesticsolipeds,ruminants,pigs,rabbitsandpoultrybredandkeptfortheproductionofmeat,skin,furorotherproducts,withtheaimofsparinganimalssufferingandstress.Thedesign,constructionandfacilitiesofslaughterhousesandtheiroperationmustcomplyand/orfacilitatecompliancewiththeruleslaiddownintheConvention.

Regulations of the United States of AmericaThereareseveraldifferentagenciesresponsibleforsettingandenforcingstandardsforanimalproductsintheUSA,includingtheUSDepartmentofAgriculture,FoodSafetyInspectionServices (USDAFSIS)andUSDepartmentofHealthandHumanServices,FoodandDrugAdministration(HHSFDA).TheUSDepartmentofAgriculture,AnimalandPlantHealthInspectionService(USDAAPHIS)isresponsibleforsettingstandardsregardingliveanimals.

TheUSDAFSIS(http://www.fsis.usda.gov)isresponsibleforthesafetyofmeat,poul-try,andeggproducts.Legislationandother informationareavailableontheRegula-

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tionsWebpages(USDAFSIS,2006a-c),andspecificinformationforcountrieswishingtoexportcanbefoundontheInternationalaffairsWebsite(USDAFSIS,2006d).Also,theFSISpublishesalistofapprovedfacilitiesinsecondcountriesandtheproductstheyareeligibletoexportintotheUSA(USDAFSIS,2006e).

TheUnitedStatesGovernment’sDepartmentofHealthandHumanServices (HHS;www.hhs.gov)istheprincipalagencyforprotectingthehealthofAmericans.TheHHSincludesmorethan300programmes,coveringawidespectrumofactivities.Inadditiontoassuringfoodanddrugsafety(undertheFoodDrugandCosmeticAct),theHHSisalsoresponsibleforhealthandsocialscienceresearch,preventingdisease(includingimmunizationservices)andcontributingtohealthinformationtechnology.

Within the HHS, the FDA (www.fda.gov) assures the safety of foods and cosmet-ics, and the safety and efficacy of pharmaceuticals, biological products and medicaldevices.TheFDAprovidesinformationregardingpoliciesanddiseases,includingBSE(USFDA,2006a).WithinFDA,theCenterforFoodSafetyandAppliedNutrition(CFSAN)isresponsibleforassuringthatFDA-regulatedfoodproducts(plantanddairyfoodsandbeverages,eggs,foodandcolouradditives,seafood,infantformulaanddietarysupple-ments)aresafe,andprovidesguidanceonexportingtheseproductsintotheUSA(USFDA,2006b).Priortoexport,FSIS investigators inspectfacilities inothercountriestoensure thatproducts imported into theUSAaremanufacturedcorrectlyand labelledtruthfully,andarenotadulteratedormisbranded.

AswiththeEU,themostcurrentapplicableUSregulationsforaparticularcommod-ity may be difficult to determine. Therefore, it is important to initiate direct bilateralcommunicationwiththeappropriateagency(FSISformeat,poultryandeggproducts,orFDAforotherfoodproducts)todeterminerequirementsfortrade.

2.3. Industry guidelines and standardsRetailersanddistributorsusefoodsafetystandardsasbasiccriteriawhensourcingprod-uctsfromprimaryproducersandothersuppliers,bothdomesticallyandinternationally.Moreandmore,thesecriteriaarebeingconfirmedthroughsupplieraudits,whichmaybeconductedby thepurchaserorbya thirdparty.Producersandsuppliers thatsup-plymorethanonepurchasermaythereforebeconfrontedwithmanydifferentsetsofcriteria,whicharesometimesconflicting,andwithmanyauditsperyear.Especiallyforproducersindevelopingcountries,meetingallthevariouscriteriacanbedifficult.

StandardsforfoodsafetyhavebeendevelopedbytheBritishRetailConsortium(BRC),resultingintheBRCGlobalStandardFood(www.brc.org.uk),whichisacceptedbythemajorityofretailers intheUKandsomeEuropeanretailers.Retailers intheUSAandelsewherehaveadoptedastandardcalledSafeQualityFood(www.sqfi.com;SQF,2000,whichoriginatedinAustraliaandisnowownedbytheFoodMarketingInstitute(FMI).TheSQFcriteriaaremeanttomanagebothsafetyandqualityoffoods,andarebasedonbothCodexandHACCPguidelines.AccordingtotheSQFWebsite,theseguidelinesarebeingusedbyover5000companiesoperatingintheAsia–Pacificregion,theNearEast,theUnitedStates,EuropeandSouthAmerica. InGermany in2002,a retailers’work-inggroupdevelopedtheInternationalFoodStandard(IFS;www.food-care.info)tohelpreducethenumberofstandards inuse.The IFSwasadoptedbytheFrenchretailers’association2003.TheIFSisalsobasedonHACCPprinciples.

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EurepGApIn1997,retailersbelongingtotheEuro-RetailerProduceWorkingGroup(EUREP)devel-opedEurepGAP(www.eurep.org),withthegoalofestablishingwidelyacceptedstand-ardsandproceduresfortheglobalcertificationofgoodagriculturalpractices(GAP)attheleveloftheprimaryproducer(EurepGAP,2006).Thesestandardsaimtopromotetheconceptsoffoodsafety,theenvironment,workers’welfareandthewelfareofanimals.

EurepGAP has now evolved into an equal partnership of primary producers andtheirretailcustomers,withallcommitteesmadeupof50%retailerand50%producerrepresentation fromallaspectsof the foodchain internationally.Therepresentativesparticipate in developing normative documents to be included within internationallyrecognizedcertificationcriteriasuchas ISO.Otherstakeholders, includingconsumerandenvironmentalorganizationsandgovernments,provide their views.Thecommit-teesalsohaveamandatetoreviewemergingissueswithsectorexperts,carryoutriskassessments(followingtheprinciplesofHACCP),andreviseandupdatetheprotocols.

TheprotocolsareusedbyproducerstoachievecompliancewithstandardsforGAPs.BecauseEurepGAP’sscopeislimitedtotheprimaryproducer,onceproductsleavethefarmtheycomeunderthecontrolofotherstandardsforfoodpackingandprocessingdescribedinthischapter.TheEurepGAPstandardsareavailableinsimpletabularfor-matandindividualcriteriaareprioritized(e.g.recommended,majormust,minormust).ThestandardsarepublishedandfreelyaccessibleontheWebsite(EurepGAP,2006).

Inordertodecreaseredundancywithotherstandards,EurepGAPallowsforachiev-ingequivalence throughbenchmarking.EurepGAPalsoaccreditsorganizations tobeabletoconductcertificationaudits,andpublishesalistofcertificationbodiesontheirWebsite.Inmostcases,costsforauditsarebornebytheprimaryproducerorproducercooperative.

Global Food Safety InitiativeInordertoestablishstandardsglobally,theGlobalFoodSafetyInitiative(GFSI)Bench-mark Project was initiated by the Food Business Forum in 2000 (www.ciesnet.com;CIES,2006).TheGFSIisgovernedbyanadvisorygroupandsupportedbyataskforcerepresentingover70%offoodretailrevenueworldwide.ThegoalsoftheGFSIareto:

• implement and maintain a scheme to recognize food safety standards world-wide;

• facilitatebettercommunication,cooperationandtransparencybetweenstandardowners;

• worktowardsworldwideintegrityandqualityinthecertificationofstandardsandtheaccreditationofcertifyingbodies(CIES,2006).

TheGFSIdoesnotproducenew foodsafety standards. Instead, it hasdevelopedabenchmarkmodel,outliningkeycriteria for foodsafetystandards,againstwhichanyfood safety or farm assurance standard can be benchmarked. These key elementsare:

• afoodsafetymanagementsystem(e.g.basedontheISO9000series);• goodmanufacturing(oragricultural)practices;• HACCP-basedsystem.

TheGFSIdevelopeditsrequirementsbasedonexistingfoodsafetystandards(includ-ingCodex,ISOstandardsandrelatedCodesofPractice),takingintoaccountconsumer

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healthandsafetyconcerns.Thus,itaimstocombinetheoryandpracticeforauditsandprovideahighlevelofprotectionfortheconsumer.

OnceafoodsafetystandardhasbeenbenchmarkedsuccessfullybyGFSI,thestand-ard becomes recognized. For example, the BRC, IFS and SQF standards (mentionedabove),amongothers,arerecognizedbytheGFSI.Therecognizedstandardscanthenbeappliedbyfoodsuppliersandretailersastheyagreeonsourcingcontractsforprod-ucts.Thespecificapplicationofstandardswillvarydependingontheproduct,aswellascompanypolicies,general regulatory requirementsandotherproduct liabilityandduediligenceregulations.

TheGFSIstandardsdifferfromISOstandardsinthatGFSIcertifiesproductsratherthanthesystemitself.TheGFSIstandardsarealsorestrictedtocertificationofsafefoodhandling.TheGFSIstandardsdifferfromEurepGAPstandards,asneitheraccreditationnorcertificationarepartoftheGFSIactivities.GFSIencouragestheuseofthirdpartyauditsusingthebenchmarkedstandards.

3. REFERENCESCIES (The Food Business Forum).2006.GlobalFoodSafety Initiative.http://www.ciesnet.com/2-

wwedo/2.2-programmes/2.2.foodsafety.gfsi.asp

Codex Alimentarius. 2006. Current official standards. http://www.codexalimentarius.net/web/

standard_list.do?lang=en

EC (European Commission).2006.Foodsafety- fromthe farmto the fork (Directorate-General

HealthandConsumerProtection)http://europa.eu.int/comm/food/index_en.htm

EU (European Union).2002.Regulation(EC)No1774/2002oftheEuropeanParliamentandofthe

Councilof3October2002layingdownhealthrulesconcerninganimalby-productsnotintended

forhumanconsumption.http://europa.eu.int/smartapi/cgi/sga_doc?smartapi!celexapi!prod!CE

LEXnumdoc&lg=EN&numdoc=32002R1774&model=guichett

EU.2006a.Eur-Lexlegislationsearchengine.http://europa.eu.int/eur-lex/en/search/search_lif.html

EU.2006c.Animalwelfare.http://europa.eu/scadplus/leg/en/s82000.htm

EurepGAp.2006.Integratedfarmassuranceprotocolshttp://www.eurepgap.org/farm/Languages/

English/documents.html

FAO. 2007. Management of transmissible spongiform encephalopathies in livestock feeds and


ISO (International Organization for Standardization). 2006. WTO TBT standards code directory.

http://www.iso.org/iso/en/comms-markets/wto/pdf/scd2005-1-en.pdf

OIE (world Organisation for Animal Health).2005a.Bovinespongiformencephalopathy.TerrestrialAnimalHealthCode,Chapter2.3.13.http://www.oie.int/eng/normes/MCode/en_chapitre_2.3.13.

htm

OIE.2005b.TerrestrialAnimalHealthCode.http://www.oie.int/eng/normes/mcode/en_sommaire.

htm

OIE. 2005c. Bovine spongiform encephalopathy. Manual of diagnostic tests and vaccines forterrestrialanimals,Chapter2.3.13.http://www.oie.int/eng/normes/mmanual/A_00064.htm

OIE. 2005d. Bovine spongiform encephalopathy disease card. http://www.oie.int/eng/maladies/

fiches/a_B115.htm

US FDA (US Food and Drug Administration). 2006a.BSEpages.http://www.fda.gov/oc/opacom/

hottopics/bse.html

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US FDA. 2006b. Center for Food Safety and Applied Nutrition international pages. http://www.

cfsan.fda.gov/~comm/intl-toc.html

USDA FSIS (US Department of Agriculture, Food Safety Inspection Services).2006a.Regulations

andpolicieshttp://www.fsis.usda.gov/Regulations_&_Policies/index.asp

USDA FSIS. 2006b. Food safety notices. http://www.fsis.usda.gov/regulations_&_policies/FSIS_

Notices_Index/index.asp

USDA FSIS.2006c.Indexoftopics.http://www.fsis.usda.gov/Help/A-Z_Index/index.asp#top

USDA FSIS.2006d.Internationalaffairs.www.fsis.usda.gov/regulations_&_policies/international_

affairs/index.asp

USDA FSIS. 2006e. Eligible foreign establishments. http://www.fsis.usda.gov/regulations_&_

policies/international_affairs/index.asp

wTO (world Trade Organization).1994,Finalactof theUruguayRound,AgreementonSanitary

andPhytosanitaryMeasures,Article5.http://www.wto.org/english/docs_e/legal_e/15-sps.pdf

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TRANSmISSIBLE SpONGIFORm ENCEpHALOpATHIES mANAGEmENT AT THE FARm LEvEL

1. GENERAL CONCEpTSPreventionandcontrolofBSEat the farm level isconceptuallydifferent fromthatofmostother infectiousdiseasesofanimals.Because theBSEagent cannotbe trans-mitteddirectlyfromonecowtoanother,traditionalmeasuressuchasquarantineandhygienearenoteffective.Thetwomeasuresthatcanbeappliedonthefarmare:

• controloflivestockfeedsandfeeding;• identificationandpropernotificationofsuspect(andotherrisk)animals.

2. LIvESTOCK FEEDS AND FEEDINGBecausecattleareexposed to theBSEagent through the ingestionof contaminatedfeed(notablyfeedcontainingmeatandbonemeal/[MBM]derivedfromruminants),pre-ventingruminant-derivedmaterialfrombeingfedtoruminantsiscrucialtopreventingexposuretotheBSEagent.Thiscontrolmustbeginwiththeappropriaterenderingofanimalby-productsandmanufacturingof feeds,butmustcontinuethroughthefarmlevel.MeasuresassociatedwithfeedmanufacturingarecoveredindepthintheCapacityBuilding forSurveillanceandPreventionofBSEandOtherZoonoticDiseasesprojectcoursemanualentitledManagementoftransmissiblespongiformencephalopathiesinlivestockfeedsandfeeding(FAO,2007a).

Many countries have feed bans in place, but these bans differ in scope amongcountries.Dependingonthespecificban,feedsorfeedcomponentscontainingrumi-nant-derivedproteinmaybeavailableforpoultry,fish,pigsorpets.Farmspurchasingcomponents for on-farm mixing of feeds intended for ruminants should understandexactlywhatisinthecomponents,andpurchaseonlycomponentsapprovedforfeed-ing to ruminants. Farms housing multiple species may be purchasing feeds or feedcomponentsnotapprovedforruminants,andthuscaremustbetakentoavoidcrosscontaminationoffeedsorfeedcomponentsforruminantswiththosefornon-ruminantsduringtransport,storage,mixingandfeeding.

3. IDENTIFICATION AND NOTIFICATION OF SUSpECT CASESThesecondfarm-levelmeasureforBSEcontrolistheidentificationandofficialnotifi-cationofBSEsuspectsorriskcattlebytheanimalownerorfarmveterinarian.Theseanimalsshouldthenbetested,andthecarcassesappropriatelydisposedofinordertominimizetheriskthatanyBSE-infectedanimalswillenterthefoodorfeedchain.

Inmostcountries,BSEis,atleastlegally,areportabledisease(FAO,2007b).Inthesecountries,BSEsuspectsmustbereportedwhenidentified.IthasbeennotedinEuropethatidentificationofthesubtlechangesassociatedwithearlyclinicalBSEisbestdonebythefarmer.However,recognitionthatanyidentifiedchangesmayindicateBSErequiresgooddiseaseawarenessandeducationofbothanimalownersandveterinarians.

Theanimalownersandveterinariansmustalsobewillingtoreportsuspectstotheofficials,whichisdirectlyrelatedtotheconsequencesofreporting.Iftheofficialcontrol

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programmeisseenasunfairor toorestrictiveor isnotadequatelycommunicatedtotheanimalowners,or if compensation for culledanimals is inadequate, thediseasewillnotbereported.

Once suspect animals are identified and reported, the official control programmemandatesthenextsteps.Ineffectiveofficialcontrolprogrammesthesuspectanimaliskilledanditsbrainremovedfortestingbyanapprovedlaboratory.Samplingmaybetheresponsibilityofofficialgovernmentveterinarians,oraccreditedprivateveterinarians.Atminimum,theobexregionofthebrainstemisremovedandtested(FAO,2007c).Thecarcassofasuspectanimalshouldnotenterthefoodorfeedchain.

Dependingonthecountry,othercategoriesofillcattlemaybepartofanationalsur-veillancesystemforTSEs,andmustalsobenotifiedandsampled.

Thegovernmentmustdevelopanddistributeeasilyunderstandableinformationabouttheofficialnotification,samplinganddisposalprocesstoallpeopleinvolvedinidentifi-cationofBSEatthefarmlevel.

3.1. Clinical signsOwingtothedifficultiesinrecognizingclinicalsignsassociatedwithBSE,Dr.U.Braunandhisstaffat theUniversityofZurich,Switzerland,developedaspecialschemeforexamination of potentially BSE infected animals (Braun et al., 1997). Animals of thisgroupincludeallcowsover30months,allanimalswithadisturbedbehaviour,andallsickorinsuredanimals.Thetestissimpleandcontainsfivepointstocheck:

1. Swayingandunsafeaction,bendingatknees,falling;2. Fearofpassageways,thresholds,channelsandotherobstaclesontheground;3. Hypersensitivitytonoise,tosuddenlight,totouchinginheadandneckregion;4. Extremelynervous,frightened,aggressive,e.g.,flinginghead;5. Sneering,dentalcrunching,drooling.

Thesesignsmightbeverysubtle,especiallyearly inthedisease.Aswell,allsignsdonotappear inallcases.Additional informationonclinicalsigns isavailable in the‘IntroductiontoTSEsandBSE’chapterofthismanual.

4. INDUSTRy STANDARDSIndustrystandards (suchasEurepGAPdescribed in thepreviouschapter),aswellasstandards for legally regulated production schemes such as “organic production” or“integratedproduction”exist formanagementofanimalsat the farmlevel.However,thesestandardscurrentlydonotmakeanyreferencetomeasurestocontrolorpreventBSE.

�. TRANSpORTForallcattle,transportshouldbeasshortandascarefulaspossibletomaintainshouldbegoodmeatquality.Noillorinjuredanimalsshouldbetransportedortheirtransportminimized.Transportationcausesstresstoanyanimalandthereforetransportationisanimportantissueforbothwelfareandmeatquality.

Aveterinarianshouldinspectanimalspriortoloading.Optimally,theinspectiontakesplaceimmediatelypriortoloading,orwithin6to12hoursofloading.Noanimalswithsignsofanyneurologicaldiseaseshouldbeloadedfortransport,ortheyshouldunder-goacompleteveterinaryexaminationpriortoloading.BSEsuspectanimalsshouldnot

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beloadedand,afterveterinaryinspection,shouldbeofficiallynotified.Insomecases,transportofcattleshowingsubtleBSEsignswillworsenthesigns,andthustheseani-malsmightbemoreeasilyrecognizedatunloading.

Legalrequirementsfortransportationofcattletoslaughtermustbedeterminedandrespected.TheOIEcodechapters3.7onanimalwelfaregivestheinternationalstandardfortransportbyland,sea,andair(OIE,2005).Otherregulationsandrecommendationsalsoexist(asdescribedinthepreviouschapterofthiscoursemanual).

�. ANImAL IDENTIFICATION AND DOCUmENTATION Animalidentificationandtraceabilityarerequiredforeffectivenationalcontrolofmanydiseases, includingBSE.Theidentificationsystemmustbeginonthefarm,andmustcontinuethroughoutthelifeoftheanimal.Therearemanydifferentsystemsinuse,butallsystemsmustguaranteethatauniqueidentifierexistsforeachanimal.Ifananimalisnevermovedfromoneplacetoanother,theidentificationsystemcanbesite-specific.Butassoonasanimalsmove,suchasystemisnolongeruseful.

Many countries have decentralized systems where identification is given througha programme (such as a dairy cattle improvement programme) or an entity such asa breed organization. There may be many databases in existence, but identified ani-malshavedocumentsthatcanbecheckedbeforeleavingoneplaceandonarrival.Indecentralizedsystems,eachorganizationisresponsibleforcontrolattheirownpoint.Animalscanonlybetracedthroughtheirlifetimesbycheckingbackstepwisethrougheachrelevantdatabase.

In centralized systems, national or even international identification systems giveuniqueidentifiers(numbers,lettersand/orcombinations)toeachnewbornanimalor,atminimum,toeachanimalatthetimewhenitleavesitsplaceofbirth.Decentralizedsystemsmaybemodifiedsothatdocumentationanddataarecontrolledcentrally,eventhoughdocumentsmaybe issuedand filledoutbydecentralized institutionsorevenindividuallybythefarmer.Thecentralsystemhastobeinformedeachtimetheanimalismoved,givingboththeplaceoforiginandarrivedatpoint.

In“animalpassport”systems,eachanimalisissueda“passport”atbirthspecifyingallindividualmarkingsandotherinformation.Thepassportfollowstheanimalandishandedoverwiththeanimalwhenownershipistransferred.Registrationcantakeplaceeitheronlywhenthepassportisissuedandwhentheanimaldiesorisslaughtered,orat every change of location. Passport systems can work with either decentralized orcentralizedsystems.

TheEUrunsanewcentralizedsystemfor importandexportsamongandbetweenEU states and other countries, called “TRACES” (TRAde Control and Expert System;EU,2006) to trackallmovementsofanimalsand toallow rapid response todiseaseoutbreaks.

�. REFERENCESBraun U, Kihm U, pusterla N, Schönmann m.1997.Clinicalexaminationofcattlewithsuspected

bovine spongiform encephalopathy (BSE). Schweiz Arch Tierheilk 139, 35-41 http://www.bse.

unizh.ch/english/examination/htmlsklinischer.htm

EU (European Union).2006.EUexportsandTRACES.http://europa.eu/rapid/pressReleasesAction.

do?reference=IP/04/487&format=HTML&aged=0&language=EN&guiLanguage=en

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FAO. 2007a. Management of transmissible spongiform encephalopathies in livestock feeds and


FAO. 2007b. Epidemiology, surveillance and risk assessment for transmissible spongiformencephalopathies.Coursemanual,ProjectCapacityBuildingforSurveillanceandPreventionofBSEandOtherZoonoticDiseases.Rome

FAO. 2007c. Diagnostic techniques for transmissible spongiform encephalopathies. Course

manual,ProjectCapacityBuildingforSurveillanceandPreventionofBSEandOtherZoonoticDiseases.Rome

OIE (world Organisation for Animal Health).2005.Codechapteronanimalwelfare.http://www.

oie.int/eng/normes/mcode/en_titre_3.7.htm

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TRANSmISSIBLE SpONGIFORm ENCEpHALOpATHIES mANAGEmENT AT THE SLAUGHTERHOUSE

1. GENERAL CONCEpTSIn the slaughterhouse, TSE management focuses on preventing material containinginfectiousprionproteinfromenteringthefoodandfeedchains.ThisisaccomplishedbyidentificationandremovalofBSEsuspectcattle,separationandsafedisposalofmate-rialpotentiallycontaininganinfectiousagent(specifiedriskmaterial/[SRM])andcontrolofcrosscontamination.

In this chapter, only slaughterhouse aspects directly related to control of BSE areincludedand,ingeneral,proceduresaredescribedforlargerslaughterhouses.Theseconceptsremainthesameforallslaughteringofcattle,butmustbeadaptedforothersituations (i.e. when the carcass is not split). Overall good manufacturing practices(GMP)forslaughteringareavailablefromCodex(www.codexalimentarius.net),andaregivenintheFAOmanualGoodpracticesforthemeatindustry(FAO,2004).

2. ANImAL IDENTIFICATIONToensuretraceabilityofandtoguaranteeproperpaymentfortheslaughteredanimal,everyanimalmustbeidentifiedandcarcassesmustbetrackablethroughtheslaugh-terhouse.Eachslaughterhousedecidesonitsownsystem,butitmustbepossibletotracebacktotheanimal’sidentityonthefarmoforiginfromeachpieceofcutmeat.

3. ARRIvAL AND ANTE mORTEm EXAmINATIONThefirstpointwhereBSEcouldpossiblybedetectedisatinitialunloadingoftheani-malsattheslaughterhouse.It isthereforevery importanttohavecattle inspectedastheycomeoffthetruck(antemortemexamination)andenterthelairage.Atminimum,thecattleshouldbeexaminedwhenmovingaroundthelairage.Inslaughterhousesinmanycountries,includingtheEuropeanUnion(EU)memberstates,theUnitedStatesofAmerica(USA)andJapan(andallslaughterhousesslaughteringbeefforexportationtooneofthesecountries),anantemortemveterinaryexaminationiscompulsory.Gener-allythisexaminationisconductedtoassesstheoverallhealthofananimal;thereforeit is important that all potential diseases (not just BSE) should be recognized. Thisrequiresthatveterinariansconductingantemortemexaminationsbewelltrainedandawareofallpotentialclinicalmanifestationsofdisease.

InSwitzerland,itiscompulsoryfortheantemortemexaminationtoincludeassess-mentofthefiveBSE-relevantpointslistedinthepreviouschapterofthiscourseman-ual.IntheEU,aswellasinothercountries,therearenodefinedspecificrequirementsforantemorteminspectionrelatedtoBSE.TherearenoregulationssofarelaboratedeitherasGMPrulesofFAOorfromtheindustry.

IfananimalispositiveonmorethanonepointoftheantemortemtestingschemeforBSE,theanimalissuspectedtobeinfectedwithBSEandmustbeseparated.Insomecasesfurtherextensiveclinicaltestingiscarriedout.AllBSEsuspectanimalsmustbekilledandasamplecollectedfortesting.Theanimalmustbemadeeasilyidentifiable

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sothatifitenterstheslaughterline,thecollectionofasampleforBSEtestingandtheexclusionofthecarcassfromthefeedandfoodchainsareensured.Suspectsshouldalsobekilledlast,attheendoftheslaughteringday,inordertominimizebothsamplingandexclusionmistakesandcrosscontaminationofothercarcasses.Officialnotificationoftheanimalasasuspectmustbegiventotheappropriateauthorities,andthecar-cassesshouldbehelduntiltheresultsoftheBSEtestareavailable.

OtherBSEriskanimals(andanimalsthatcouldbeillwithotherimportantdiseases)such as emergency slaughter or down-in-truck animals should either be killed in aslaughterhousespecificallydesignatedforthispurposeorbekilledlast,attheendoftheslaughteringday,aswithBSEsuspects.TheseanimalsshouldalsobetestedforBSE,forreasonsdescribedintheCapacityBuildingforSurveillanceandPreventionofBSEandOtherZoonoticDiseasescoursemanualentitledEpidemiology,surveillance,andriskassessmentfortransmissiblespongiformencephalopathies(FAO,2007).Theseanimalsshouldalsobeexaminedespeciallycarefullyforotherdiseasesduringsubse-quentveterinaryinspections.Ifslaughteredontheregularline(andifnotcondemnedforotherreasons),thecarcassesshouldbehelduntiltheresultsoftheBSEtestareavailable.

Theantemorteminspectionisespeciallyimportant,becausesubsequentveterinaryinspectionsof thecarcassarenotuseful indiagnosingBSE. Inspections for carcasshygieneandspinalcordremovalare,however,importantforcontrolofcrosscontami-nation.

4. STUNNING, pITHING AND BLEEDINGStunningisthefirststepoftheslaughterprocess. Inmanycountries,officialregula-tions do not allow killing of an animal without stunning it prior to bleeding. In ritual(halalorkosher)slaughtering,animalsarekilledandbledwithoutfirststunning.

Therearedifferentmethodsandtechniquesavailableforstunning.Themostcom-monstunningmethodinEuropeandtheUSAiscaptiveboltstunning.Ithasbeensug-gestedthatbecausetheskullisopenedandthebrainisdamagedbypenetrationofthestunningboltwiththistechnique,thereisapotentialforcontaminationoftheworkingenvironmentandtheslaughterline.Therefore,anybraintissuefoundoutsidetheskullshouldbecollectedanddiscarded.Becausebraintissuecansticktothebolt’sconcaveandsharpenedendpoint,theboltshouldbecleanedataregularfrequencyusingswabsorpaper.Usedswabsorpapermustbediscardedappropriately.

Atechniquecalled“concussionstunning”waslaunchedbyacompanyintheUKin2000inanattempttominimizedamagetotheskullandthusminimizecontamination,aswellasminimizeboththerisktoworkersandtheriskofbrainparticlesenteringthebloodvesselsandlungs.Thetechniqueiscontroversial,astheEuropeanFoodSafetyAuthority (EFSA) showed that there is no real improvement in security (EFSA, 2004).AnothertechniquequitecommonlyusedinNewZealandiselectricalstunning,whichisnowunderdevelopmentinEurope.Therearesomenegativeanimalwelfareaspectstoelectricalstunning,whicharenotyetthoroughlysolved.

Thegoalistoachieveimmediateunconsciousnessoftheanimalwithoutstressingitbeforeandduringstunning.Thereforethecorrectfunctioning,handlingandposition-ingof thestunningdevicearevery important.AnexcellentdescriptionofcaptiveboltstunningisavailableinGrandin(2006).Allnon-conformitiessuchasdoublestunningorfailuresshouldbedocumented.

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Pithingistheseveredamagingofthebrainandspinalcordofslaughteredcattlebyinsertingametalrodthroughtheholeintheskullmadebythecaptiveboltstunner.Thegoalofpithingistoprotectthesafetyofslaughterhouseworkersshacklingthelimbsofstunnedanimals,asitpreventsviolentlimbmovementafterstunning.PithinghasbeenforbiddenintheEUandSwitzerlandsince2001becauseoftheriskofcontaminatingthecarcassandtheenvironmentwithbraintissue.Asanalternativesomeslaughterhousesintroducedelectricaldepolarization(fixingaclipwithelectricallowtensionatthemuz-zle)tocontrollimbmovement.

Foranimalwelfarereasons,aminimumwaitingperiodofthreeminutesshouldbegivenafterbleedinguntilthenextstepinordertoallowtheanimaltodie.

�. HIDE AND HEAD REmOvALTocontrolcrosscontaminationatheadremoval,atwo-knifetechniqueistheoptimalmethodtoused.Withafirstknife,themuscles,connectivetissueandtendonsofthedorsalneckarecutinacircularcut.Then,withasecondknife,thespinalcordiscutbetweentheskullandthefirstvertebra.Therestoftheneckisthencutwiththefirstknifetoremovetheheadfromthecarcass.

Hideremovalcanbedonemanuallyorbymeansofahidepuller.Olderhidepullersworkfrombottomupwhereashidepullersofthenewergenerationworkfromtopdown.Also,ifthehideisremovedmanually,itisworkedfromtopdowntopreventcontamina-tionofthecarcass.

Headremovalcanbedonebeforeorafterhideremoval.Inslaughterhouseswithhidepullingfromthetopdown,thehideisoftenpulledwiththeheadonandheadremovalisdoneonlyafterhideremoval.SamplingforBSEtestingcanbedoneeitherbeforeheadremovalorafter,butoptimallywhenthecarcassandheadareeasilyidentifiable.TheeyesareconsideredasSRMandmustbediscardedwiththehead;thusitisimportantthattheeyesremainattached.

If thehead is toberemovedafter thehide, itmaybenecessarybefore thehide isremoved,firsttocutthespinalcordbymeansofaneckstick(throughthehide).Thecontaminationleftbytheretractingknifeisnegligiblebecausethepotentiallycontami-natedtissueoftheligamentumnuchaewillnotenterthefoodchain.Cuttingthespinalcord first is necessary with some hide pullers for technical reasons, i.e. the carcassbecomessostretchedthatthespinalcord isundertensionatheadremoval,causingthecordtoretractorevenbreakfromthebrainstem,affectingtheabilitytocollectthecorrectbrainstemsamplesforBSEtesting.

�. SAmpLINGSamplingforBSEtestingisstraightforwardandthetechniqueiseasyaftersomeprac-tice(DEFRA,2004).Theanatomyofthebrainstemandtherationalebehindthesampletaken are fully described in the Capacity Building for Surveillance and Prevention ofBSE and Other Zoonotic Diseases project course manual Diagnostic techniques fortransmissiblespongiformencephalopathies(FAO,2007b).Itmustbeemphasizedthatunlessthecorrectbrainsamplesaretakenandhandledappropriately, falsenegativetestsmayresult.

Samplescanbecollectedaftertheheadhasbeenseparatedfromthebodybetweentheskullandthefirstvertebra,withtheheadeitherstillattachedorremovedfromthe

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body.Thechoicewilldependonthelayoutoftheline,theavailablespaceandthedesignoftheworkingplaceduringdehiding,headremovalandmeatinspection.

Samplesarecollectedthroughtheforamenmagnumwithaspecialspoon.Specially-marketedspoonsareavailablefromBSEtestsuppliersoramediumsizemetalspoonmaybesharpenedonbothsidesforcuttingoffthebrainsteminsideoftheskull.Withthe removedhead lyingon itsdorsalsurface (in removedheads), thespoon is intro-ducedalongthedorsaledgeoftheforamenmagnumandisrotatedtotheleft-ortotheright-handsideforcuttingofthebrainsamplebeforepullingoutthroughthehole.Samples are then placed into marked plastic cups with screw caps and transportedtothelaboratory.Plasticsample(“whirl”)bagsmaybeused,butarelessdesirableastheyaremorecomplicatedtouseinacompletelyhygienicway.Thetissueanatomycanbecomedistortedifthesamplesarecrushedduringshipment.

All samples have to be identified with sampling date, slaughterhouse identifica-tion, identification of person responsible for sampling, the animal’s unique identifiernumber, theslaughternumber, indicationabout theoriginof theanimalandanimalriskcategory.

Specialattentionmustbepaidtodevelopingasystemontheslaughterlinetoopti-mizethecorrectidentificationandmatchingofcarcassandsample.Systemsofdoublechecksshouldbeimplementedinordertofollowtheprocesscorrectly.Inmanycoun-tries, when BSE positive results are determined, the positive carcass as well as thecarcassbeforeandthecarcassafterinlineareallblockedinthecoolerinordertobeabletoensurethecorrectidentity.InSwitzerland,theDNAoftheear,carcassmeatandbrainofallthreeanimalsarecomparedtothepositivesampleforconfirmation.

Different systems with different goals for sampling must be developed and imple-mented incountrieswherecarcassesarenotheld in thecoolerbutare immediatelydisseminatedforconsumption.

�. CARCASS SpLITTING AND SpINAL CORD REmOvALFollowingevisceration,thecarcassissplitverticallyinhalfsothatthecarcasscanbefurtherinspectedandreducedtoamanageablesize.CarcasssplittingisthepointintheslaughterprocesswiththehighestriskofcontaminationwiththeBSEagent.

Meatcleaversorothermeansofsplittingareoftenusedinsmallerslaughterhouses,andbandsaws,reciprocatingsawsorcircularsawsareusedinlargerslaughterhouses.Thecutismadethroughthemidlineofthespinalcolumnalthoughsomeveeringfromthemidlineinevitablytakesplace.Ifsplittingisnotpreciselyinthemidlineofthespinalcolumn,theremightbetheformationofapersisting“tunnel”,whichhastobeopenedmanuallybysawingorwithachopper.Aftersplitting,thespinalcordisremovedeithermanuallybyscratchingoutwithathumbknifeorbyspeciallydesignedpowerdevicesthatsuckorscratchorboth(BVS-Kreis,2001;Jarvis,2006).Itisveryimportantthatnocarcassarrivesatchillingwiththeremainsofthespinalcordinthecanal.

Aspinalcordremovaldevicewasdevelopedin2001todecreasecontaminationduringsplittingandwastermedthe‘ArminKreismethod’.Withthismethod,atubeisintro-ducedintothespinalcanalpriortosplitting.Asthetubeisdrivenforwardinthecanal,itcontinuouslyaspiresthespinalcordandremovesit.Theadvantageofthistechniqueisthatthereisnosplashingandthereforenocontaminationthroughsplitting.Thedis-advantage–andthusthereasonforpoorsuccessintheindustry–isthatpartsofthe

43

TSE management

at the

slaughterhouse

duramaterremain,requiringtimeandlabourtocleanthecanalagainmanuallyaftersplitting.

�. CONTROL OF CROSS CONTAmINATIONCross contamination risk exists mostly through utensils, knives, saws and suckingdevicesatspinalcordremoval.Althoughcontroversyexistsastotheextentoftherisk,itisclearthatsomepreventivemeasuresarenecessary.

Thebestpracticeforcontrolofcrosscontaminationduringtheslaughterprocessisa“two-knife”technique(includingthatforheadremoval,describedinsection5ofthischapter),withknivesexchangedaftereachanimalorafteracut in “dirty”parts.Forexample,duringpreparationforhideremoval,thefirstknifeisusedtocutthroughthehideandthesecondknifeisusedtoremovetheskin,becauseduringremovaltheknifehascontactwiththe“clean”meatsurface.ForallknifecutswithSRMcontact,separatekniveshavetobeused,withthebestpracticebeingtouseaknifeofadifferentcolour(e.g.redforSRMcontact).

Ithasbeenshownthatthesplashingofrinsingwaterfromthesplittingsawcancon-taminatethebacksofthecarcassesina10-cm-largeareathatincreasesfromthetopdown.Therefore,measuresshouldbeimplementedtodecreasethesplashing,andtheuseofwaterforrinsingcarcassesduringslaughtermustbereducedtotheminimum.

It isalso important tocollectwastewaterandparticleson the floor,and toensurethatworkersincontactwithSRMwearprotectiveglassesandgloves.Specialattentionshouldbegiventoregularsanitizationofprotectiveclothesandthehandsofpersonnel.Moreover,personnelshouldnotfollowcarcassesfromdirtytocleanzones,i.e.person-nel remaineitheratworkingplacesbetweenstunninganddehidingorbetweenhideremovalthrougheviscerationtoweighingofcarcasses.

�. INSpECTION AND IDENTIFICATION OF SpECIFIED RISK mATERIAL Veterinaryinspectionofthecarcassgenerallyfollowscarcasssplitting.Theinspectionismeanttoidentifysignsofdiseaseinthecarcassandensurethesafetyofthemeat.ItisnolongerpossibletodiagnoseBSEatthispoint.

Intheveterinaryexamination,inadditiontothevisualinspectionoftheslaughteredanimal,certainorgans(e.g. lungs, liver,spleen,uterus,udderandtongue)shouldbepalpatedandsomeorgans(includinglymphnodes)shouldbecutopenandinspectedtodeterminewhetherornottheanimalwassufferingfromanydisease.

TheEUrequiresthatthetongueshouldbefreedtopermitadetailedinspectionofthemouthandthepharynx.Thehead,throat,retro-pharyngeal,submaxillaryandparotidlymphnodesandthetonsilsshouldbeexamined.Thetonsilsmustberemovedafterinspection and treated as SRM. The lungs, trachea, oesophagus, and bronchial andmediastinal lymph nodes must also be inspected, as well as the pericardium, heart,diaphragm, liver,gallbladder,bileductsandthehepaticandpancreatic lymphnodes(whicharenotSRM).Signsofdiseaseshouldbefurtherinvestigatedandsamplestakenasrequiredbynationalregulations.

Atthistime,theinspectormustalsoensurethatallSRMhasbeenremoved.SRMisdefineddifferentlybydifferentcountries,andmay includeage-specificcategorizationofrisktissues.SRMisalsodefineddifferentlyforsheepandgoats.MoreinformationonSRMcanbefoundinthechapter1ofthiscoursemanual.Inallcountriesbrainand

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spinalcordareconsideredSRM(thoughtheagemayvary).Thus,thespinalcanalandtheareaaround itshouldbespecificallyexaminedandconfirmed freeofspinalcordtissueandduramater.

Althoughblood isnotconsideredasSRM, itshouldbekept inmindthat thebloodfromcattletestingpositiveforBSEhasprobablybeencollected.Measuresforelimina-tionorfurthertreatmentofthebloodmightbeconsidered.

Incertainslaughterlinelayouts,thisfinalSRMinspectionpointmightbelater(e.g.beforeweighingcarcasses).Inanycaseitisimportanttodefineresponsibilityforensur-ingthetotalabsenceofSRM,eitherbyatrainedmemberofthemeatinspectionteamoradesignatedtrainedandresponsibleemployeefromtheslaughterhouse.NoremainsofSRMshouldbefoundoncarcassesafterweighingandgrading.

10. DISpOSAL OF SpECIFIED RISK mATERIAL AllSRMseparatedduringslaughtershouldbecollectedinspeciallymarkedcontainersandkeptseparatedfromallotherby-products.Crosscontaminationshouldbepreventedeitherthroughgeographicalseparation(i.e.adifferentroomforcollectorbins)orinstal-lations(e.g.panels,covers)forsplashprotection.EliminatedSRMmustnotre-enterthefood/feedchainandshouldoptimallybeburned.Burningcanbebydirectincinerationofthewaste,orafterprocessing(e.g.renderingintoMBM).ThelatteronlyworksifallMBMisburnedorseparatelinesforMBMproductionexist.InSwitzerland,SRMisrenderedintoMBM,andallMBMisthenburnedduringtheproductionofconcrete.

11. REFERENCESBvS-Kreis. 2000. Vacuum removal of spinal cord core from the closed or halved spinal canal.

http://www.bvs-kreis.de/html/overview.html

DEFRA (Department for Environment Food and Rural Affairs, UK).2004.BSEsurveillanceincattle

slaughteredforhumanconsumption–24-30monthcasualtyandbeefassuranceschemecattle.

http://www.defra.gov.uk/animalh/bse/otm/review/sampling.pdf

EFSA (European Food Safety Authority).2004.OpinionoftheEuropeanFoodSafetyAuthorityon

BSEriskfromdisseminationofbrainparticlesinbloodandcarcassfollowingstunning.http://

www.efsa.eu.int/science/biohaz/biohaz_opinions/731_en.html

FAO.2004.Goodpracticesforthemeatindustry.FAOAnimalProductionandHealthManualNo.2.

Rome(alsoavailableatftp://ftp.fao.org/docrep/fao/007/y5454e/y5454e00.pdf)

FAO. 2007a. Epidemiology, surveillance, and risk assessment for transmissible spongiformencephalopathies.Coursemanual,ProjectCapacityBuildingforSurveillanceandPreventionofBSEandOtherZoonoticDiseases.Rome

FAO. 2007b. Diagnostic techniques for transmissible spongiform encephalopathies. Course

manual,ProjectCapacityBuildingforSurveillanceandPreventionofBSEandOtherZoonoticDiseases. Rome

Grandin T.2006.Recommendedcaptiveboltstunningtechniques forcattle.http://www.grandin.

com/humane/cap.bolt.tips.html

Jarvis. 2006. The Jarvis Model SR-1 vacuum system for spinal cord removal on beef or hogs.

http://www.jarvisproducts.com/Jarvis%20Pork%20SR1.htm

4�

TSE management

at the processing

plant

TRANSmISSIBLE SpONGIFORm ENCEpHALOpATHIES mANAGEmENT AT THE pROCESSING pLANT

1. GENERAL CONCEpTSAfterslaughter,furtherprocessingofmeatandproductionofmeatproductsareoftencarriedoutatadifferentlocation.Carcassesmaybedeliveredtotheprocessingplantfromoneormoreslaughterhouses.Alternatively,theremaybeacuttinganddeboningsectionwithintheslaughterhouse.Normally,inthislattercase,personnelandmate-rialflowarecompletelyseparatedfromtheslaughteringareawiththeonlyconnectionthroughthechillingarea,andbarriersmustbeinstalledandrespected.Ineithercase,itiscrucialthatallmeatisfreefromspecifiedriskmaterial(SRM)beforeitisprocessed.The only SRM that should be permitted to enter the processing plant (or processingarea)arevertebralcolumns.

Forfoodsafetyreasonsit iscrucialtomaintaintraceabilitythroughprocessing.Allrecallsofpotentiallycontaminatedmeatandmeatproductsrelyontheabilitytotracethe products back to the slaughterhouse of origin, although some countries or indi-vidualretailersrequirefurthertraceabilitytothefarmoforigin.

2. SRm CONTROLAroutineprocedureshouldbeestablishedfor inspectionforSRMonarrivalateitherthe cutting/deboning plant, or at the processing section of the slaughterhouse. Thisinspectionshouldbeenforcedevenifthecarcassesarrivefromanattachedslaughter-house.Thisisparticularlyimportantwhenquartersorhalvesofcarcassesarrive,astheabsenceofspinalcordmaterialinthevertebralcolumnhastobeensured.

3. DEBONING AND HANDLING OF SRmIn theEU, the vertebral columnof cattleolder than12months, including thedorsalrootganglia(DRG),isclassifiedasSRM.RemovaloftheDRGisdifficulttocontrolfullyvisually,becausethechannelsleadingfromthespinalcolumnareverynarrow.InPlate1,thevertebralchannelshavebeenopenedtoshowtherelativeanatomyofthespinalcordandDRG.

Theindividualspinalcordsectionscorrespondtothevertebralcolumnsections,asthespinalcordsendsoutaspinalcordnerveintotheperipherybetweentwovertebraeoneoneachside.Thus,thespinalcordisdividedintoneck,chest,loinandcrosscordsectionsandthenumberofspinalcordnervescorrespondstothenumberofvertebraeofthesinglesection.Onlytheneckhassevenvertebraeandeightnecknerves,asthefirstnecknerveleavesthespinalcordbetweentheoccipitalboneandtheatlasandthelastnecknervebetweenthelastneckvertebraeandthefirstchestvertebrae.

Consideringtheanatomy,appropriatemeasureshavetobeinplacesothatDRGareeliminatedcompletelyfromthemusclecuts.ItisimportantthatnoSRMcontactstheknivesorcutting/deboningtablestominimizetheriskthatsurfacesbecomecontami-nated.ThebestpracticeforadjusteddeboningprocedureswouldbetoleavemeatintheanglesofthevertebraenearthelocationoftheDRG.

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4. mECHANICALLy RECOvERED mEAT Mechanical recovery of meat (MRM; called advanced meat recovery/[AMR] in NorthAmerica) is a process that can be used after traditional deboning to maximize theremovalofmeatfromthebones.Inthisprocess,developedinthe1970s,carcassbonesthathavealreadybeenstrippedofmostmeatareputthroughamachinethatcrushesthebonesandappliespressuresothatfurthermeat isremoved.Theextractedmeatslurry that is produced can be used for sausages, pies, burgers and other products.Becauseof thefragmentsofbonethatarepresent in theslurry, the levelofcalciumpresentintheproduct(alsoreferredtoasMRM)ishigherthaninnormalmeat,butthisisnotthoughttobeamajorproblem.

TheMRMcanberecoveredfrombothcookedanduncookedbones.Traditionally,onlythevertebrae,ribs,shoulderbladeandpelvisareusedforMRMduetothedifficultiesin effectively hand boning these regions. Long bones with high marrow content areconsideredunsuitablebecauseofthehighconcentrationofcalcium,ironandpurines(whichmayleadtodiseaseinhumansingestinglargequantities)inthemarrowthatisextrudedfromthebonesduringprocessing.Headsarealsogenerallynotsubjectedtothisprocess.

Themachinesusedtorecovertheresidualmeatvaryindesignandaction.Manyuseapistontosubjectbonestoveryhighpressureinordertoextractthemusclefromthem.Theythenforcetheresultantslurrythroughaseriesofsievestoremoveanylargepar-ticles.Connectivetissueandcollagenarealsoremovedatthispoint.

BecauseoftheriskofspinalcordorDRGbeingpresentinvertebralcolumns,manycountrieshaveissuedBSE-relevantregulationsbanningorrestrictingtheproductionofMRM,eitherfrombovinevertebrae,fromallbovinebones,orentirely.

Anothertypeofmeatrecoveryiscalled“Baadering”orsoftseparation(Baader,2006).UsingmachinerymanufacturedbyBaader,productsaregentlysqueezedthroughaper-forateddrumsothatsoftertissues(meatandfat)areseparatedfromthehardertissues(tendons,ligaments,cartilage,bones).ThisprocessisstillusedinEuropetoremoveredmeatfromtendonsandligaments.

�. REFERENCES Baader.2006.RedmeatBaadering.http://www.baader.com/Red_Meat_Baadering.105.0.html

plate 1

Spinalcord,dorsalrootgangliaandassociatedtissuesPHOT

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4�

Quality control

concepts, hygiene,

and HACCp in the

meat industry

QUALITy CONTROL CONCEpTS, HyGIENE AND HACCp IN THE mEAT INDUSTRy

1. GENERAL CONCEpTSModernlegislationisnolongerbasedentirelyuponofficialcontroloffoodproduction.Moreandmore,itistheresponsibilityofeachproducertobeabletodemonstratethattheproductsproducedaresafe,conformtolegalrequirements,andareofgoodquality(i.e.acceptablebytheconsumer).Therefore,thetoolsforcontrolhavehadtochange.

Conceptually, there is a difference between “quality control” and “quality manage-ment.”Qualitycontrolreferstomeasurestakenforsupervisionofproduction.Qualitymanagementgoesfurther,andisnotonlyproductrelatedbutincludesorganizationalparameterssuchasstaffresponsibilitiesandcompetences,andisdirectedtoproduc-tion environment and product flow. These parameters are considered “prerequisiteprogrammes” (PRPs),whichareestablishedmeasuresorprogrammes thatarewellimplemented,maintainedandcontinuallyimproved.ThePRPsincludebothqualitycon-trolandautocontrolmeasures.ThesemeasuresareimportantnotspecificallyforTSEmanagement,butfortheproductionofsafeandqualityproductsingeneral.

TheCodexdocumentGeneralPrinciplesofFoodHygieneprovidesstandardprinciplesfortheproductionofsafefood.Theseprincipleshelptoensurefoodhygienewhenusedwiththecodeofhygienicpracticeandtheguidelinesonmicrobiologicalcriteriaforeachspecificproduct.Thedocumentfollowsthefoodchainfromprimaryproductionthroughto final consumption, highlighting the key hygiene controls at each stage. It recom-mendsaHazardAnalysisandCriticalControlPoint(HACCP)-basedapproachwhereverpossibletoenhancefoodsafety(CodexAlimentarius,2003).

2. QUALITy CONTROLQualitycontrolsystemsareusuallysystemsorprogrammesthatenableanorganizationtoproducecontinuouslyproductsofadeterminedandconsistentqualityandthusfulfilcustomerrequirements.ThePRPsarethebasisofaHACCPsystem,areanessentialpartofgoodmanufacturingpractices (GMPs)orgoodhygienicpractices (GHPs),andincludethefollowingaspects:

• Hygienemonitoring• Hygienerules(e.g.personnel,visitors,contractors)• Facilitydesign(e.g.productionlayout,productionflows)• Maintenanceprogramme• Hygieneandsanitation• Pestcontrol• Productcontrol• Temperaturecontrol• Traceability(e.g.recallprocedure,batchcontrol)• Incidentmanagement• Water/air/energycontrol• Hygienetraining• Productanalysis(intermediateandendproduct)

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Inthischapter,onlyfacilitydesignandhygieneandsanitation(offacilitiesandper-sonnel)aredescribed,astheyhaveadirectimpactoncontrolofcrosscontaminationforBSEandotherinfectiouszoonoticdiseases.

3. FACILITy DESIGNFacilitiesshouldbedesignedtooptimizethesafetyandqualityofproductsproduced.There are no international regulations for facility layouts, but the legislation of mostcountries (e.g. Canada, EU, Switzerland, USA) include general requirements for thedesignoftheworkingenvironment(floors,wallsandceilings,aswellasinstallations).TherearenospecialrequestsrelatingtoTSEmanagementinslaughteringanddebon-ing,norinfurtherprocessing.However,animalby-productsmustbehandledinawaythat guarantees separation and prevention of cross contamination at all times. ThisreferstoSRMandallRiskCategory3by-productsfromslaughter(asdescribedintheCapacityBuildingforSurveillanceandPreventionofBSEandOtherZoonoticDiseasesproject course manual Management of transmissible spongiform encephalopathiesinlivestockfeedsandfeeding,(FAO,2007),aswellasby-productsfromdeboningandfurtherprocessing(e.g.vertebralcolumn).

4. HyGIENE AND SANITATIONThe general principles of Codex Alimentarius (2003) state that appropriate facilitiesandproceduresshouldbe inplace toensure thatanynecessarycleaningandmain-tenance are carried out effectively and an appropriate degree of personal hygiene ismaintained.

4.1. FacilityTherearemanydifferentwaystokeepafacilityinacleanandhygieniccondition.Clean-ingiseitherdonebyinternalpersonnelafterfinishingotherworkorstaffhiredspecifi-cally forthispurpose,or it isdonebyasubcontractedspecializedcleaningcompany.Cleaningagentsandequipmentshouldbeappropriateforthetask(s),includingusingthe appropriate disinfectants. Personnel engaged for cleaning must undergo specialtrainingforhygiene,cleansingtechniqueandsecurity.

The effectiveness of the cleaning should be regularly verified by personnel notinvolvedinthecleaning.Thiscanbevisuallyorusingmicrobiologicaltestingofhigh-risksurfacesor,optimally,both.

4.2. personnelSignificanteffortandattentionmustbegiventoestablishingandmaintainingeffectivepersonalhygieneforallstaff,bothtopreventcrosscontaminationofproductsandtoreducetheriskofstaffexposuretoinfectiveagents.

Personalhygienerequirescontinuoustrainingtoensurethatpersonnelunderstandthe rules, and there should be supervision to ensure that personal hygiene is main-tained(cleanclothes,handwashing,changinggloves,etc.).

Visitors to facilities should be minimized. When visitors are present, appropriatehygienemeasuresshouldbetaken(e.g.disposableshoecovers,externalclothing,andhaircoversworn).Allvisitorsshouldbesupervisedatalltimes.Attentionmustalsobepaidtomaintaininghygieneduringvisitsoffacilitystaffnotnormallyworkinginproduc-tionareas.

4�

Quality control

concepts, hygiene,

and HACCp in the

meat industry

�. HACCpHACCPisariskmanagementsystemthatwasdevelopedinthelate1960s.HACCPhasbeenrecognisedbytheCodexAlimentariusCommitteesince1996(CodexAlimentarius,2003),whichdefines itas“asystemwhichidentifies,evaluates,andcontrolshazardswhicharesignificantforfoodsafety”.HACCPisnotaqualitycontrolsystem,butrefer-ences such systems to manage identified risks. All prerequisite (risk management)programmesarebasedonGMPstoensurefoodhygieneandsafety.Thus,HACCPcanonlyworkifappropriateGMPsareinplace.

HACCPcanbeappliedtonearlyanyprocess(e.g.slaughterhouses,renderingplants,processingplants).Ifcorrectlyimplemented,HACCPcanimprovetheproductsecurityofalltheseprocessors.However,itiscrucialthatthehazardanalysisbedonecorrectly,includingusingascientificapproachspecifictotheprocess,identifyingallpossibleandrelevant microbiological, chemical and physical hazards, and providing an accuratequalitativeandquantitativeestimationoftherisk.AllthetwelvestepsfortheapplicationofaHACCPmustbefollowed,andoptimallytheHACCPdocumentationshouldcontainfullcommentsorexplanationsregardingeachCCPwiththesite/productspecificaction.Staff in all facilities implementing HACCP, and particularly the HACCP team leader,shouldbetrainedandoptimallyshouldhavepracticalexperienceinthefield.

HACCP is an efficient tool if potential hazards can be analysed, critical limits canbeestablishedandtested,and(if limitsareexceeded)correctiveactionispossible. Ifthesecriteriaarenotmetforahazard,thereisnoCCPforcontrolofthehazardandthereforenopossibilitytoeliminate,topreventoreventoreduceit,andaCCPshouldnotbedefined(althoughGMPsandqualitycontrolsmaystillbeapplied).ACCPwhichisdefinedbutwhichcannotimprovesafetyoftheproducedproductmayleadtoafalseassumptionofsecurityandthusmustbeavoided.

Thus,asthereisnowaytotestforTSEcontaminationintheslaughterhouseorforthepresenceoftheagentinmeatormeatproducts,HACCPislargelynotapplicabletoTSEmanagement.

�. REFERENCESCodex Alimentarius. 2003. FAO/WHO Recommended International Code of Practice, FAO/WHO

Generalprinciplesoffoodhygiene,CAC/RCP1-1969,Rev.4-2003.http://www.codexalimentarius.

net/download/standards/23/cxp_001e.pdf http://www.codexalimentarius.net/web/standard_list.

do?lang=en

FAO. 2007. Management of transmissible spongiform encephalopathies in livestock feeds andfeeding.Coursemanual,ProjectCapacityBuildingforSurveillanceandPreventionofBSEandOtherZoonoticDiseases.Rome

1AppENDIX

Authors and course contributors

�3

Appendix 1

Authors and course contributors

AUTHORS AND COURSE CONTRIBUTORS

Catherine Botteron NeuroCenter,UniversityofBerne,Switzerlandmarcus Doherr VetSuisseFaculty,UniversityofBerne,SwitzerlandAnou Dreyfus FAO,AnimalProductionandHealthDivision,Rome,ItalyChristine Friedli SAFOSO,Berne,SwitzerlandDagmar Heim SwissFederalVeterinaryOffice,Berne,SwitzerlandUlrich Kihm SAFOSO,Berne,SwitzerlandElizabeth mumford SAFOSO,Berne,Switzerlandmanon Schuppers SAFOSO,Berne,SwitzerlandTorsten Seuberlich NeuroCenter,UniversityofBerne,SwitzerlandAndrew Speedy FAO,AnimalProductionandHealthDivision,Rome,Italymarc vandevelde NeuroCenter,UniversityofBerne,SwitzerlandAndreas Zurbriggen NeuroCenter,UniversityofBerne,Switzerland

Participants from the partner countries have also contributed significantly to theproductionand translationof thecoursemanuals,and tomanyotheraspectsof thecourses.

2AppENDIX

Related background reading and web links*

*ThesereferencesandWeblinksrefertoallfourCapacityBuildingforSurveillanceand Prevention of BSE and Other Zoonotic Diseases project course manuals.Therefore,alldocumentsandlinksmaynotbeapplicabletothetopicscoveredinthismanual.

*ThesereferencesandWeblinksrefertoallfourCapacityBuildingforSurveillanceand Prevention of BSE and Other Zoonotic Diseases project course manuals.Therefore,alldocumentsandlinksmaynotbeapplicabletothetopicscoveredinthismanual.

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Appendix 2

Related background reading and web links

RELATED BACKGROUND READING AND wEB LINKS

TSE pages of selected ministries and other general data sourcesDepartment of Environment Food and Rural Affairs. United Kingdom, BSE homepage:

http://www.defra.gov.uk/animalh/bse/index.html

FAO. BSEpages:http://www.fao.org/ag/AGAinfo/subjects/en/health/bse/default.html

ministry of Agriculture of New Zealand. BSE homepage: http://www.biosecurity.govt.nz/

node/7650

Swiss Federal veterinary Office. BSE homepage: http://www.bvet.admin.ch/gesundheit_tiere/

01752/01804/02075/index.html?lang=de

TAFS.Positionpapers:http://www.tseandfoodsafety.org/startseite.htm

United States Department of Agriculture. Animal and Plant Health Inspection Service, BSE

homepage:http://www.aphis.usda.gov/lpa/issues/bse/bse.html

wHO.BSEpages:http://www.who.int/zoonoses/diseases/bse/en/

International standardsOIE. Bovine spongiform encephalopathy. Terrestrial Animal Health Code, Chapter 2.3.13. http://

www.oie.int/eng/normes/MCode/en_chapitre_2.3.13.htm

OIE. Factors to consider in conducting the bovine spongiform encephalopathy risk assessment

recommendedinchapter2.3.13.TerrestrialAnimalHealthCode,Appendix3.8.5.http://www.oie.

int/eng/normes/MCode/en_chapitre_3.8.5.htm

OIE.Surveillanceforbovinespongiformencephalopathy.TerrestrialAnimalHealthCode,Appendix

3.8.4.http://www.oie.int/eng/normes/MCode/en_chapitre_3.8.4.htm

OIE. Procedures for the reduction of infectivity of transmissible spongiform encephalopathy

agents.TerrestrialAnimalHealthCode,Appendix3.6.3.http://www.oie.int/eng/normes/MCode/

en_chapitre_3.6.3.htm

OIE.1994.AgreementonSanitaryandPhytosanitaryMeasures.FinalActoftheUruguayRound,Article5.http://www.wto.org/english/docs_e/legal_e/15-sps.pdf

BSE cases and risk EC. BSE testing results of member countries of the EU. http://europa.eu.int/comm/food/food/

biosafety/bse/mthly_reps_en.htm

OIE.NumberofreportedcasesofBSEworldwide.http://www.oie.int/eng/info/en_esbmonde.htm

OIE.ResolutionNo.XXVII,Recognitionofthebovinespongiformencephalopathystatusofmember

countrieshttp://www.oie.int/eng/info/en_statesb.htm#List

SSC. 2002. Opinion on TSE infectivity distribution in ruminant tissues (state of knowledge,

December2001).AdoptedbytheScientificSteeringCommitteeatitsmeetingof10-11January

2002.http://europa.eu.int/comm/food/fs/sc/ssc/out241_en.pdf

SSC.OpinionsoftheScientificSteeringCommitteeoftheEC.http://europa.eu.int/comm/food/fs/

sc/ssc/outcome_en.html

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measuresEU. 2002. Regulation No 1774/2002. Laying down health rules concerning animal by-products

not intended for human consumption. http://europa.eu.int/eur-lex/pri/en/oj/dat/2002/l_273/

l_27320021010en00010095.pdf

European Union Guidance Document for Regulation 1��4/2002. http://europa.eu.int/comm/food/

fs/bse/bse48_en.pdf

FAO. 2004. Good practices for the meat industry. FAO Animal Production and Health Manual

No. 2. Rome (also available at: ftp://ftp.fao.org/docrep/fao/007/y5454e/y5454e00.pdf).

FAO. 2004. protein sources for the animal feed industry. Proceedings of the FAO Expert

ConsultationandWorkshop,Bangkok,29April-3May2002.FAOAnimalProductionandHealth

ProceedingsNo.1.Rome(alsoavailableathttp://www.fao.org/documents/show_cdr.asp?url_)

file=/docrep/007/y5019e/y5019e00.htm

FAO. 2007. Management of transmissible spongiform encephalopathies in livestock feeds andfeeding.Coursemanual,ProjectCapacityBuildingforSurveillanceandPreventionofBSEandOtherZoonoticDiseases.Rome

FAO. 2007. Management of transmissible spongiform encephalopathies in meat production.Course manual, Project Capacity Building for Surveillance and Prevention of BSE and OtherZoonoticDiseases.Rome


Europe.RevScitechOffintEpiz22(1),179-199

Heim D, mumford E.2005.ThefutureofBSEfromtheglobalperspective.MeatScience70:555-

562

Heim D, murray N.2004.Possibilities tomanage theBSEepidemic:cohortcullingversusherd

culling–experiencesinSwitzerland.In:Prions:achallengeforscience,medicineandthepublichealthsystem,2nded.EdsHFRabaneau,JCinatl,HWDoerr.Karger,Basel,Switzerland.pp

186-192

OIE.2005.DiseasesnotifiabletotheOIE.http://www.oie.int/eng/maladies/en_classification.htm

Render – The National magazine of Rendering. 2004. Rendering 101: Raw material, renderingprocess,andanimalby-products.http://www.rendermagazine.com/August2004/Rendering101.pdf

The BSE Inquiry. 2000.Thereport.TheinquiryintoBSEandvariantCJDintheUnitedKingdom,Volume13: Industryprocessesandcontrols,Chapter6,Rendering.http://www.bseinquiry.gov.

uk/report/volume13/chapter6.htm

DiagnosticsEFSA. 2006.EFSAScientific reportson theevaluationofBSE/TSE tests.http://www.efsa.eu.int/

science/tse_assessments/bse_tse/catindex_de.html

OIE. 2005. Bovine spongiform encephalopathy. Manual of diagnostic tests and vaccines forterrestrialanimals,Chapter2.3.13.http://www.oie.int/eng/normes/mmanual/A_00064.htm

Safar JG, Scott m, monaghan J, Deering C, Didorenko S, vergara J, Ball H, Legname G, Leclerc

E, Solforosi L, Serban H, Groth D, Burton DR, prusiner SB, williamson RA. 2002.Measuring

prionscausingbovinespongiformencephalopathyorchronicwastingdiseasebyimmunoassays

andtransgenicmice.NatBiotechnol20(11):1147-1150.

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Appendix 2

Related background reading and web links

SurveillanceCameron AR, Baldock FC. 1998. Two-stage sampling in surveys to substantiate freedom from

disease.PrevVetMed34:19-30

Salman mD.2003.AnimalDiseaseSurveillanceandSurveySystems.MethodsandApplications.

IowaStatePress,Ames,Iowa,USA

Scheaffer RL, mendenhall w, Ott L.1990.ElementarySurveySampling.DuxburyPress,Belmont

CA.

Clinical examinationBraun U, Kihm U, pusterla N, Schönmann m.1997.Clinicalexaminationofcattlewithsuspected

bovinespongiformencephalopathy(BSE).SchweizArchTierheilk139:35-41(alsoavailableat:

http://www.bse.unizh.ch/english/examination/htmlsklinischer.htm)

Human prion diseasesDepartment of Health,UnitedKingdom.CJD-homepage:

http://www.dh.gov.uk/PolicyAndGuidance/HealthAndSocialCareTopics/CJD/fs/en

3AppENDIX

Glossary of technical terms and acronyms*

*ThisglossaryreferstoallfourCapacityBuildingforSurveillanceandPreventionofBSEandOtherZoonoticDiseasesprojectcoursemanuals.Therefore,alldocu-mentsandlinksmaynotbeapplicabletothetopicscoveredinthismanual.

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Appendix 3

Glossary of technical terms and acronyms

GLOSSARy OF TECHNICAL TERmS AND ACRONymS

AAFCO AssociationofAmericanFeedControlOfficials

Ab Antibody

AFIA AmericanFeedIndustryAssociation

Animal by-products Tissues and other materials (including fallen stock) dis-cardedattheslaughterhouse,whichgenerallygotoincin-eration,burialorrendering(dependingonthecountry)

Animal waste Animalby-products

Ante mortem Before death (generally refers to the period immediatelybeforeslaughter)

Ap Apparentprevalence

BAB Bornaftertheban;animalswithBSEthatwerebornafterimplementationofafeedban

BARB Bornafter the realban;animalswithBSE thatwerebornafter implementation of a comprehensive and effectively-enforcedfeedban

BSC Biosafetycabinet

BSE Bovinespongiformencephalopathy

BL Biosafetylevel

By-pass proteins Proteinsthatarenotdegradedintherumenbutaredigest-edinthesmallintestinetoprovideadditionalaminoacids

CCp Critical Control Point: a step in a production chain that isessential to prevent or eliminate a food safety hazard orreduceittoanacceptablelevelandatwhichacontrolcanbeapplied

CEN EuropanCommitteeforStandardization

CJD Creutzfeldt-JakobDisease

CNS Centralnervoussystem

Combinable crops Thoseabletobeharvestedwithacombine

Contaminants Materialsthatshouldnotbepresentinagivenproduct;e.g.rodents,birds,rodentdroppings,toxinsandmouldarecon-taminantsthatshouldnotbepresentinanylivestockfeed

Control (noun) The state wherein correct procedures are being followedandcriteriaarebeingmet(HACCPcontext)

Control (verb) Totakeallnecessaryactionstoensureandmaintaincom-pliancewithcriteriaestablishedinaHACCP(orothercon-trol)plan(HACCPcontext)

Core fragment ThepartofPrPScthatisnotdigestedbyproteinaseK(alsocalledPrPRes)

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Critical limit Acriterionthatseparatesacceptabilityfromunacceptability(e.g.duringaudits)

Cross contaminants Substancescarriedfromareasormaterialswheretheyarenotprohibitedtoareasormaterialswheretheyareprohib-ited

Cross feeding The feeding of a livestock group with prohibited feedsintendedforanotherlivestockgroup

Cp Crudeprotein

CwD Chronicwastingdisease.

DNA Deoxyribonucleic acid; the genetic material for all livingorganismsexceptbacteria

Downer cattle Cattletoosicktowalktoslaughter(definitiondiffersamongcountries)

EC EuropeanCommission

EFSA EuropeanFoodSafetyAuthority

ELISA Enzyme-linkedimmunosorbentassay

Emergency slaughter Slaughter cattle with clinical signs non-specific for BSE(definitiondiffersamongcountries)

Epitope Structuralpartofanantigenthatreactswithantibodies

Epitope demasking Processinwhichtheepitopebecomesavailableforantibodybinding(forexample,bydenaturation)

Essential amino acids Those that cannot be synthesized and therefore must beprovidedbythefeed/food

EU EuropeanUnion

Fallen stock Cattlethatdiedorwerekilledforunknownreasons(defini-tiondiffersamongcountries)

FAO FoodandAgricultureOrganizationoftheUnitedNations

FDA FoodandDrugAdministration(UnitedStatesofAmerica)

FEFAC EuropeanFeedManufacturers’Federation

FIFO Firstinfirstout;aproductionconcepttooptimizequality

Flushing batches Batchesof feedprocessedortransported in-betweenfeedbatchescontainingprohibitedandnon-prohibitedmaterials,andintendedtoremovetracesofprohibitedmaterialsfromtheequipment

FmD Foot-and-mouthdisease

FN False negatives; truly-diseased animals that test negativeonadiagnostictest

Fp Falsepositives;trulynondiseasedanimalsthattestpositiveonadiagnostictest

FSE Felinespongiformencephalopathy;TSEincats,believedtobecausedbyingestionoftheBSEagent.

GAFTA GrainandFeedTradeAssociation

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GAp Goodagriculturalpractices

GBR GeographicalBSEriskassessment

GHp Goodhygienepractices

Gmp GoodManufacturingPractices

GmT Goodmicrobiologicaltechnique

Greaves Aproteinaceousby-productoftherenderingprocess

GTm GAFTATradersManual

H & E Haematoxylinandeosinstain

HACCp Hazard Analysis and Critical Control Points: a method toidentifyprocessstepswherea lossorsignificantdeviancefromtherequiredproductqualityandsafetycouldoccurifnotargetedcontrolisapplied

HACCp plan Adocumentprepared inaccordancewith theprinciplesofHACCPtoensurecontrolofhazardsthataresignificantforthesegmentoftheproductionunderconsideration

Hazard Abiological,chemicalorphysicalagentwiththepotentialtocauseanadversehealtheffect

Hazard analysis The process of collecting and evaluating information onhazardsandconditionsleadingtotheirpresencetodecidewhich are significant for the segment of the produc-tion under consideration and therefore which should beaddressedinthecontrol(orHACCP)plan

High quality protein Proteinsourcesthatmatchtherequirementsofaparticularspeciesorproductionclasswell

HpLC Highperformanceliquidchromatography

IAG EuropeanFeedMicroscopistsworkinggroup

IFIF InternationalFeedIndustryFederation

IHC Immunohistochemistry

Indigenous BSE case DomesticBSEcase;non-importedBSEcase

m+C Methioninepluscysteine;aminoacidsgenerallyconsideredtogether,becausecysteinecanbederivedfrommethionineinanimals

ISO InternationalOrganizationforStandardization

mammal Ananimalthatlactates;inthiscontext,livestockexcludingaquaticspeciesandpoultry

mBm Meatandbonemeal; thesolidproteinproductof theren-deringprocess

medulla oblongata Caudalportionofthebrainstem

mmBm Mammalianmeatandbonemeal

monitoring Anongoingprocessofspecificanimalhealthdatacollectionoveradefinedperiodoftime

monogastric species Animalswithsimplestomachs(e.g.swine,poultry,horses,humans)

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mOSS Monitoringandsurveillancesystem

mRm Mechanicallyrecoveredmeat

NIRC Nearinfraredcamera

NIRm Nearinfraredmicroscopy

NIRS Nearinfraredspectrography

Notifiable disease Adiseaseforwhichthereisanationallegalrequirementtoreportcasesandsuspectstoanofficialauthority

Obex Thepointonthemidlineofthedorsalsurfaceofthemedullaoblongata thatmarks thecaudalangleof the fourthbrainventricle;amarkerfortheregionofthebrainstemwheresomeof thepredilection areas forhistological lesionsandPrPSc deposition in BSE are located (such as the dorsalnucleusofthevagus)

OD Opticaldensity

OIE WorldOrganizationforAnimalHealth

OR Oddsratio

pathogenicity Ability of an organism to invade a host organism and tocausedisease

pCR Polymerasechainreaction

pithing The laceration of central nervous tissue by means of anelongated rod-shaped instrument introduced into the cra-nialcavityofslaughtercattleafterstunning.

pK Proteinase K; a serine proteinase that digests PrPC com-pletelybutPrPSconlypartiallyundercertainconditions

post mortem Afterdeath

prion InfectiousagentcausingTSE

proteolysis Cleavage of a protein by proteases; also referred to as“digestion”

prp Prion protein, encoded by the gene PRNP, expressed bymanycelltypesandmanyorganisms

prpBSE Resistant prion protein associated with bovine spongiformencephalopathy;alsocalledPrPSc

prpC Normalprionproteinfoundineukaryoticcells

prpRes Resistantprionproteincore remainingafterproteolysisofPrPScusingproteinaseK

prpSc Resistant prion protein associated with transmissiblespongiformencephalopathies,includingBSE

prpSens Normalprionproteinfoundineukaryoticcells;alsocalledPrPC

pv Predictivevalue

Rapid test Test systems using immunological assays that detect thepresence of infectious agents in animal tissues or othermaterialswithinhours

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RR Relativerisk

Ruminant species Animals with multichambered stomachs that allow bacte-rial fermentationof feedsprior to intestinaldigestion (e.g.cattle,sheep,goats,camellids)

Scrapie ATSEofsheepandgoats

SE Sensitivityofadiagnostictest

Segregation Undesirable separation of raw ingredients in a compoundfeedafterprocessing

SFT SwissInstituteofFeedTechnology

Sick slaughter Cattle with non-specific signs (definition differs amongcountries)

Sp Specificityofadiagnostictest

SpS Agreement AgreementontheApplicationofSanitaryandPhytosanitaryMeasures

SRm Specifiedriskmaterials;thoseanimaltissuesmostlikelytocontainTSEinfectivematerial

SSC Scientific Steering Committee of the European Commis-sion

Strip test Lateralflowimmunochromatographictestforrapiddetec-tionofproteinsinfeedsamples

Surveillance Extension of monitoring in which control or eradicationactionistakenonceapredefinedlevelofthehealth-relatedeventhasbeenreached

TAFS InternationalForumforTSEandFoodSafety

TBT Agreement AgreementonTechnicalBarrierstoTrade

Terrestrial animal In thiscontextall livestockexcludingaquaticspecies (e.g.poultry,ruminants,pigs,horses)

TmE Transmissibleminkencephalopathy

Tp Trueprevalence

Tracing Determiningwhereananimalorproductoriginatedorhasbeen

Tracking Following an animal or product forward through the sys-tem

TSE Transmissiblespongiformencephalopathy

UK UnitedKingdomofGreatBritainandNorthernIreland

USA UnitedStatesofAmerica

vCJD Variant (or new variant) Creutzfeldt-Jakob disease ofhumans; believed to be caused by ingestion of the BSEagent

wB Westernblot

wHO WorldHealthOrganization

wTO WorldTradeOrganization

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Additionaldefinitionscanbefoundin• the OIE Terrestrial Animal Code, Chapter 1.1.1. http://www.oie.int/eng/normes/

MCode/en_chapitre_1.1.1.htm• theFAO/WHOCodexAlimentarius“Currentofficialstandards”.http://www.codex-

alimentarius.net/web/standard_list.do?lang=en

4AppENDIX

project summary

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Appendix 4

project summary

pROJECT SUmmARy

ThiscourseisapartoftheprojectCapacityBuildingforSurveillanceandPreventionofBSEandOtherZoonoticDiseases.Theaimoftheprojectistobuildcapacity,establishpreventivemeasuresandanalyserisksforbovinespongiformencephalopathy(BSE),sothat,ultimately,partnercountriesareableeithertoprovethemselvestobeBSE-freeorareabletodecreasetheirBSErisktoanacceptablelevel.Governmentalandprivateveterinary services, diagnostic laboratories, and the livestock, food and animal feedindustrieswillbestrengthenedandsupported,andtechnicalcapacitybuiltateverystepalongthefoodproductionchain.Inthefuture,theknowledgegainedduringthisprojectcould be used by the countries to establish similar programmes for control of otherzoonoticfood-bornepathogens.

TheprojectisfundedbySwissgovernmentalagenciesandutilizesexpertiseavailableinSwitzerlandandworldwideandinfrastructureavailablefromtheFoodandAgricul-tureOrganizationoftheUnitedNations(FAO)toassistthegovernmentsofthepartnercountriestoachievetheproject’saim.TheexecutingagencyisSafeFoodSolutionsInc.(SAFOSO)ofBerne,Switzerland.

The direct project partner in each country is the National Veterinary Office. Thecountriescommitandpayasalary toat leastone individual,situated in theNationalVeterinaryOffice,toactasaNationalProjectCoordinator(NPC),committhreetraineespercourseandprovidethenecessaryinfrastructureforimplementationoftheprojectinthecountry.TheNPCisresponsibleforcoordinatingtheactivitiesoftheprojectwithinthecountry,includingofferingtrainingcourses,identifyingandorganizingtrainees,andpromotingcommunicationbetweentheproject,thegovernment,thescientificcommu-nityinthecountry,thelivestockandfoodindustries,andthepublic.Othercommitmentsby the countries include providing paid leave time for employees to attend courses,providing infrastructure and facilities for in-country courses, providing historical andcurrentdata(surveillancedata,animalmovementdata,import/exportrecords)andthestaffrequiredtoidentifythosedata,andprovidingadequatestaffforandfacilitatingtheinitialneedsassessmentandfinalcomprehensiveriskassessment.

ANationalProjectBoardineachoftheparticipatingcountriesregularlyevaluatestheoperationalprogressandneedsoftheproject,andprovidesaregularvenueforcom-munication among the project team, national partners and stakeholders. This BoardiscomprisedoftheNPC,representativesofthenationalgovernment,aprojectrepre-sentative,thelocalFAOrepresentative,andlocalstakeholdersfromprivateindustryandtheveterinarycommunity.

ACTIvITIES OF THE pROJECT1. Thespecificneedsofeachparticipatingcountryareassessed.2. Comprehensive courses to “train the trainers” are provided in Switzerland (or

elsewhere)toselectedparticipantstoimproveunderstandingoftheepidemiologyofandrelevantriskfactorsforBSEandtodevelopspecificknowledgeandskillsforimplementingappropriatecontrols.

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Threetraineesfromeachcountry,aswellastheNPC,traveltoSwitzerland(orelse-where)toparticipateineachcourse.

Thecoursesare:• DiagnosticTechniquesfortransmissiblespongiformencephalopathies• Epidemiology, Surveillance and Risk Assessment for transmissible spongiform

encephalopathies• Transmissiblespongiformencephalopathiesmanagementinlivestockfeedsand

Feeding• TransmissiblespongiformencephalopathiesManagementinMeatProduction

EachcourseisprecededbyanintroductiontoBSEcoveringthebackgroundoftrans-missiblespongiformencephalopathies,BSE,biosafety,generalconceptsofepidemiolo-gyandriskassessment,andriskcommunication.Eachcoursealsoincludesdiscussionofaspectsofriskcommunicationthatarerelevanttothetopicbeingpresented.

Onlythosemotivatedindividualswhowillbeimplementingtherelevantinformationinto the national BSE programme, who have some experience (e.g. ability to use amicroscope,veterinarytraining)andhaveadequateEnglishskills,areaccepted.

After each course, the relative success of the course is evaluated focusing on thesuccess of the training methods and effectiveness of the knowledge transfer ratherthanonthelearningoftheindividualtrainees.Therefore,nowrittentestisgiven,butclosecontact ismaintainedwiththetraineesaftertheyreturntotheircountries,andtheirprogressandsuccess in implementationof their training into thenationalBSEprogrammeisfollowedandevaluatedinthefield.

3. Eachof theTSE-specificcourses is thenofferedasan in-countrycourse in thenative language, and is organized by the trainees and the National VeterinaryOfficeswithtechnicalsupportfromtheproject.In-countrycoursesusethesamecurriculumandexpectedoutcomesastheoriginalcourses,andareprovidedwithsupport,technicalassistanceandmaterials(translatedintotheirownlanguage).TheintroductoryTSEandbiosafetycoursecurriculumisalsopresented.Atleastoneexpert trainerassists inpresenting thesecourses.Participantsarechosenaccordingtostrictselectioncriteria,butthenumberofparticipantsandthefre-quencyandlocationofcoursesgivendependsontheneedsofthecountryandthetypeofcourse.

4. The knowledge gained through the courses should then be integrated by thepartnercountrythroughdevelopmentandimplementationofanationalBSEcon-trolprogramme.Theprogrammeispromotedandsupportedbythecountriestoensurethesustainabilityofthesystem.Contact,technicalsupportandfollow-upwiththecountriesisongoingthroughouttheproject.

5. InformationcampaignstoimproveBSEawarenessaretargetedtonationalgov-ernments,producersandconsumers.

6. PartnercountriesaresupportedinthesubmissionofacomprehensivenationalBSEriskassessmenttotheWorldOrganisationforAnimalHealth(OIE)inordertodocumenttheirBSEstatustotheinternationalcommunity.

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