Descriptivestatisticswerecomputedtoexplorevariablesgatheredfromthedatasources.Means,medians,andpercentileswerecomputedforcontinuousvariableswhilefrequencytableswerecomputedforcategoricalvariables.
The2020editionoftheFMDChapterintheTerrestrialCodestipulatesthatMemberscanapplyfortherecoveryofFMD-freestatuswithin24monthsafterthedateofsuspension.IfFMD-freestatuscannotberecoveredwithinthisperiod,MemberswouldneedtofollowthegeneralprovisionsforrecognitionofFMD-freestatus.However,thisdeadlineof24monthswasonlydescribedintheTerrestrialCodeeditionsof2002andfrom2015onwards.Itwasnotedthatthetime-to-applicationforrecoveryaftersuspensionwaswithin24monthsin75%ofstudyunits;within36monthsin90%ofthestudyunitsandupto5yearsfortheremaining10%ofstudyunits.ConsideringthatthisdeadlinewasnotdescribedintheFMDChapterofalltheeditionsoftheTerrestrialCodeofthestudyperiod,athresholdof36monthswasusedforthepurposesofthestudy.Studyunitsforwhichanapplicationforrecoverywasnotsubmittedwithin36monthsaftersuspensionorbytheendofthestudyperiodwereprogressivelyrightcensored.
Thecurrentstudydocumentsthesuspensions,andrecoveriesofFMD-freestatusfrom1996,whenWOAHfirststartedgrantingofficialFMD-freestatustoitsMembers,untilthefirstsemesterof2020.InformationhasbeensynthesizedfromofficialdocumentationsubmittedbyMemberstoWOAHandsomeexternalsources.ThisuniquestudyhasallowedtoexploreandunderstandtheriskfactorsthatcouldaffectthetimetakentorecoverFMD-freestatusafterithadbeensuspended,andtousethatunderstandingtohelpnationalveterinaryservicestomakeinformeddecisionstomanageFMDatthecountrylevel.Thisdiscussionstartsaddressinggeneralfindingsatthedescriptiveanalysis,thencontinuestodiscussthemainfindingsatthesurvivalanalysis,andconcludeswithlimitationsofthestudy.
InregardtothepercentageoflivestockpopulationatriskduringFMDoutbreaks,itwasfoundthatfewerthan8%ofthetotallivestockpopulationineachstudyunitwereconsideredatrisk,and75%ofoutbreakswerelocalizedevents,whichmeansthattheywererestrictedtoalimitedareaofthestudyunit.Consideringtherelativelylowpercentageoflivestockaffectedandatrisk,andthelocalizednatureoftheseoutbreaks,itispertinenttoaskwhyMembersdidnotopttoapplyfortheestablishmentofacontainmentzone(CZ)asastrategytohastentherecoveryofatleastpartoftheirterritories.SincetheinclusionofprovisionsfortheestablishmentofaCZinthe2008editionoftheTerrestrialCode,thisapproachhasbeenimplementedinonlythreecases(17%).
TherewasalsoevidencethatthestudyunitswhichsharedborderswithFMD-infectedcountriesorzoneswerelesslikelytorecovertheirFMD-freestatusrapidly.ThisisanimportantfindingforMemberstoconsider.TheymayconsidernationalstrategiesthatimplementtargetedorheightenedsurveillanceintheseborderareasaimedattheearlydetectionofFMDvintroduction,aswellasstricterpreventionstrategiesandcontrolsinthemovementofanimalsandanimalproductstoandfromtheseareas,potentially(butnotnecessarily)withinazoningapproach.ThefindingemphasizestheimportanceofregionalcollaborationintransboundaryFMDriskmanagement,bothinpreventingoutbreaksandalsoduringcontroloperationsduringoutbreaks.
Interestingly,itwasobservedthatthestudyunitsthathadtheirFMD-freestatussuspendedwithin12monthsafterrecognitionorrecovery,weremorelikelytotakealongertimetorecoverfromasubsequentoutbreak.ThisfindingillustratesthevulnerabilityofcountriesandzonesintheperiodafterFMDrecognition/recovery,andtheneedforfollow-upworktobedonetomaintaintheFMD-freestatus.ThismaysuggestaneedtoprioritizeresourcesandactivitiesandmaintainvigilanceagainstFMD,particularlyduringthefirstyearofFMD-freestatus,forsuccessfulorcontinuousmaintenanceofthatstatus.ThisisalsoarelevantconsiderationforWOAHtoputaparticularemphasisinfollowingupcountriesorzonesduringthefirstyearafterattainingFMD-freestatus.
TheanalysiscouldnotfindanyassociationbetweentheexistenceofaPPPrelatedtoFMDactivitiesandthetimetorecovertheFMD-freestatus.Nevertheless,theauthorsnotedtheimportanceofPPPsinthemaintenanceofanimalhealthstatusanddiseasecontrolinMembersthroughincreasingawarenessandincentivisingriskmanagement,andMembersshouldthereforebeencouragedtoprovidesuchdatawhenapplyingforofficialrecognitionorrecoveryofFMD-freestatus.Inaddition,theauthorsrecommendWOAHtodevelopaharmonizedmethodologytorecordthistypeofdataordevelopindicatorstoevaluatetheimpactofthiskindofcollaborationinapplicantMembersinthefuture.
Thefollowinglimitationsoftheanalysisshouldalsobenoted.TheFMDChapterintheTerrestrialCode(2002edition,andeditionssince2015)indicatesa24-monthdeadlinetoapplyforrecoveryafterthesuspensionofFMD-freestatus;thiswasnotincludedinothereditionsoftheTerrestrialCode.Therefore,somestudyunitshadalongerperiodfromsuspensiontorecovery(upto5years).ToavoidthosestudysubjectswithprolongedperiodsbetweenthesuspensionoftheirFMD-freestatusandtheirapplicationforrecoveryaffectingtheanalysis,aperiodof36monthswaschosenasathresholdfortheinclusionofthestudyunits.Thisthresholdwasalsochosentoincludealargerproportionofstudyunits,since90%fallwithinthisrange.Thecurrentstudydoesnothavealargesamplesize(n=45),andthiscouldaffectthepowertodetectassociationsbetweenvariablesandthetimetakentorecoverFMD-freestatus.
ThisstudywasconceivedbyWOAH.Thedatacollection,entry,andcleaningweredonebyAC.AC,PT,andMS-Vcontributedtothestatisticalanalyses.Allauthorscontributedtothestudydesign,wrotethereport,read,andapprovedthefinalversionforpublication.
ThisprojectwassupportedbyAgricultureandAgri-FoodCanada(AAFC),throughafundingcontribution(LetterRef.AD/ARB/2018/483)totheWorldOrganisationforAnimalHealth(WOAH).
Theauthorsdeclarethattheresearchwasconductedintheabsenceofanycommercialorfinancialrelationshipsthatcouldbeconstruedasapotentialconflictofinterest.
ThereviewerMEdeclaredapastco-authorshipwithoneoftheauthorMS-Vtothehandlingeditor.
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Keywords:footandmouthdisease,officialFMD-freestatus,suspensionofFMD-freestatus,recoveryofFMD-freestatus,WOAHMembers,survivalanalysis
Citation:CabezasAH,MapitseNJ,TizzaniP,Sanchez-VazquezMJ,StoneMandParkM-K(2022)AnalysisofsuspensionsandrecoveriesofofficialfootandmouthdiseasefreestatusofWOAHMembersbetween1996and2020.Front.Vet.Sci.9:1013768.doi:10.3389/fvets.2022.1013768
Received:07August2022;Accepted:14October2022;Published:28October2022.
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Disclaimer:Allclaimsexpressedinthisarticlearesolelythoseoftheauthorsanddonotnecessarilyrepresentthoseoftheiraffiliatedorganizations,orthoseofthepublisher,theeditorsandthereviewers.Anyproductthatmaybeevaluatedinthisarticleorclaimthatmaybemadebyitsmanufacturerisnotguaranteedorendorsedbythepublisher.