美国呼吸道疾病防控

StevenD.DudleyDVMPresidentCEOVeterinaryMedicalCenter/PrairieLivestockSupplyWorthingtonMN美国控制猪呼吸道疾病的经验ControlofSwineRespiratoryDiseas`eintheUSA我们今天要谈谈下列疾病的控制经验

WewilltalkaboutSwineDiseasesbelowtoday圆环病毒病

(PCVD)Porcinecircovirusdisease蓝耳病(PRRSV)(BlueEar)

猪流感病毒SwineInfluenzaVirus猪圆环病毒-临床症状包括

PorcineCircovirus–clinicalproblemsinclude:影响繁殖Reproductiveeffects猪圆环相关的繁殖障碍疾病PCV2AssociatedReproductiveFailure猪圆环导致胎盘感染PCV2Uterineinfectionofpiglets对生长猪的影响EffectsonGrowingPigs呼吸系统-肺炎Respiratory–pneumonia消瘦Gauntwasteawaypigs皮炎Dermatitisskinlesions肠炎（伴有体重减轻和轻度呼吸系统综合症）Enteritiswithweight-losswithminimalrespiratorycomplications加重其他病原的感染Allowsotherpathogenstobecomemoresevere猪圆环感染特点

CharacteristicsofPCV2Infection猪圆环病毒血症期长，较其它病毒更难以彻底清除PCV2infectionhaslongerviremiaandlongerclearancethanmostotherviraldiseases.生命力顽强PCV2virusisarobustvirusthatishardtokill.猪圆环的免疫抑制可引起其它疾病Immuno-suppressionaffectsfromPCV2arewidelynotedcausinganincreaseimpactofotherdiseases.繁殖障碍ReproductiveeffectsofPCV2可在任何时间感染母猪Infectionofsowsoccursatanytime当母猪和后备母猪的抗体水平下降的时候，仔猪感染风险增加Risk

ofinfectiontopigletsincreaseswhensoworgiltantibodiesdecrease.感染来源

SourceofPCV2infection母猪群感染InfectiontoSowHerd最常见途径是通过阴性后备猪或未免疫后备猪Mostcommonrouteofinfectionisnaivegiltsorpoorlyvaccinatedgilts后备猪出现病毒血症-胎盘带毒继而感染仔猪Giltsbecomeviremic–virusthengoestotheuterusandpigletsbecomeinfected.仔猪感染InfectiontoPiglets病毒血症的怀孕母猪通过胎盘感染仔猪Pigletinfectionoccursfromsowviremiainutero通过病毒血症产后母猪的鼻腔分泌物感染Exposuretonasalsecretionsfromviremicsowsafterfarrowing初乳带毒Colostrumcanbeasourceofinfection猪圆环病毒-免疫方案

PorcineCircovirus–PrinciplesofSowVaccination免疫方案-如果种猪群有问题

VaccinationProtocol–BreedingHerdifproblemsarepresent用圆环灭活苗或组织苗对所有母猪普注，3周后加强一次

Massvaccinateentirebreedingherdandrepeatin3weeks免疫母猪以防止生产障碍Vaccinatesowstopreventreproductivedisease

priortobreeding为保持整个群体稳定、抗体整齐，除母猪普注外，后备母猪进入生产群6周前也要免疫一次

Followinginitialmassvaccination,maintainstableanduniformherdimmunitylevelbyvaccinatingallreplacementgiltsbeforetransfertobreedingherd

猪圆环在母猪群的流行情况

PCV2prevalenceinsowherdsDr.DarinMadsenISUpresentation最近研究表明，临床表现有繁殖障碍的母猪群中，50%以上的母猪感染有圆环病毒Recentstudiesshowmorethan50%ofsowherdsareaffectedwithsomesortofreproductivecomponent.多数在引进后备母猪时进行免疫Mostherdsvaccinatereplacementgiltsenteringtheherd多数美国人不接种怀孕母猪Mostproducersarenotroutinelyvaccinatingthebreedingherd建议免疫母猪群（以及仔猪免疫）Recommendvaccinatingsowherds

(inadditiontopigletvaccination)免疫母猪和后备母猪可避免以下两种情况SowandgiltvaccinationwillpreventthetworeproductiveeffectsofPCV2繁殖障碍ReproductiveFailure胎盘感染UterineInfection免疫母猪的好处AdvantagesofSowvaccination提高母猪和后备母猪的抗体水平Increaseantibodylevelsinsowsandgilts减少母猪和后备母猪的病毒血症Decreaseviremiainsowsandgilts母猪接种圆环疫苗的弊端

DisadvantagesfromvaccinatingsowswithPCV2不免疫母猪的原因ReasonstonotvaccinatesowsforPCV2vaccineinthesowherd花费大Costofthevaccine母源抗体干扰仔猪免疫Maternalinterferenceofpigletvaccination仍然有争议Continuestobedebated母猪免疫的益处

Additionalreasonstovaccinatesows继发感染-415个来源不同的母猪场Secondaryeffectsseenon415differentsowfarms.免疫母猪Vaccinatedsowsthensee减少断奶到配种的时间decreaseweantoservice降低母猪死亡率decreasesowmortality降低仔猪死亡率decreasepigletmortality增加仔猪断奶重increasepigletweanweight.怀孕母猪的亚临床感染下降Decreasesubclinicalportionofinfectioninthebreedingherd.最近发现如果同时免疫母猪和哺乳仔猪可降低保育猪的发病率Recenttrendnotedthatifvaccinatebothsowsandpigletswillseedecreasedproblemsinthenursery.猪圆环病毒影响母猪有2种表现

SowsimpactedbyPCV2intwoways

繁殖障碍PCV2associatedreproductivefailure引起后备母猪和母猪的临床症状Clinicalaffectsongiltsandsows后备母猪和母猪食欲下降GiltsandSowsgoofffeed偶尔发生流产Abortionscanoccurbutrare主要引起死胎和木乃伊胎Primarilyseestillbornsandmummies将死胎送检实验室Diagnosisismadebysendinginstillbornlitterstolab

胎盘感染PCV2uterineinfection母猪和后备母猪不表现明显的临床症状Noclinicalaffectstosowsorgilts新生弱仔带毒WeakpigletsbornthathavethePCV2virusinthem猪圆环相关的繁殖障碍

PCV2associatedreproductivefailure母猪未经免疫时IfnoPCV2sowvaccineisusedISUestimatesthat12%的死胎与猪圆环相关12%ofstillbornlittersatISUwereassociatedwithPCV2需排除可导致死胎和木乃伊胎的其它疾病Otherdiseaseproblemsthatneedtoberuledoutifstillbornsandmummiesarepresent首先排除猪细小病毒PorcineParvo猪蓝耳病毒PRRSvirus猪流感SwineInfluenza样品数很重要Numbersubmittedisimportant.当问题猪有50%以上感染了PCV2的话，意味着问题很大WhenPCV2problemsonly50%ofstillbornsareinfected每窝至少3个阴性仔猪以确定未感染Send3pigletsfromeachlittertoruleoutdiseasepresence冻存死胎，一次性送检Foreaseofsendingsamples,keepstillbornsinfreezerorfrigandcollect.Thensubmitatonetime..胎盘感染PCV2uterineinfection比繁殖障碍更普遍Morecommonthanreproductivefailure感染所有的胎次Allparitiesaffected无临床表现NoClinicalsignsingiltsorsows主要产弱仔Primarilyseeweakbornpiglets.妊娠期对仔猪的影响

Effectsofpigletinfectionduringgestation妊娠早期Infectionearlyingestation心肌感染heartinfection(myocardialinfection)死胎Pigletsborndead妊娠后期Infectioninlategestation淋巴凋亡lymphoiddepletion弱仔Weakpigsborn继发感染MorelikelytohavePCV2associateddiseaselater妊娠后期（70天后）仔猪可产生主动免疫PigscandevelopimmunitytoPCV2ifexposedinlategestation(after70daysofgestation)仔猪产生抗体PigletsbuildantibodiestoPCV2仔猪出生后抗体阳性PigletsbornwithpositiveantibodytoPCV2诊断Diagnosismadebytesting样品需为初乳前的仔猪血清Pigletsfromsowsusingpre-suckledserum2项检测LookingfortwodifferentthingsPCR–检测病毒抗原testingforthePCV2virusIFA–检测抗体testingforantibodypresence母猪的免疫时间

Timingofsowvaccination如何确定接种时间Sowvaccinationneedtoconsidertiming不建议产前免疫Pre-farrowvaccineisnotrecommended因为母源抗体水平的升高会对仔猪免疫反应产生影响Thiswillincreasematernalantibodiestoalevelthatwillinterferewithpigletvaccinationresponse母猪和后备母猪在产后或者配种前接种Wanttovaccinatesowsandgiltspostfarroworprebreeding配种前-114天内，母猪的抗体水平下降，继而初乳里的抗体水平也下降Pre-breeding-114daysforsowantibodylevelstodecreasewhichwoulddecreasethelevelofantibodiesinthecolostrum增加仔猪免疫的成功率Thiswillimprovethechanceofsuccessfulpigletvaccination仔猪免疫时间

Pigletvaccinationtiming母源抗体对仔猪免疫可能存在一定的影响Impactofmaternalantibodylevelsinpigletsmayinterferewithsuccessfulvaccinationforpiglets在美国，这个仍是个待探讨的问题ThiscontinuestobedebatedbyveterinariansintheUSDr.Madsen认为高母抗对仔猪免疫影响不大Dr.MadsenatISUthinksifhighantibodiesaretransmittedtothepigletthatthiscouldnegativelyaffectpigletvaccination如果IFA值在320及以下则无影响UsingIFAtestingif1:320orbelownointerference.如果高于320，则可能有干扰Above320theninterferencemaybeaproblem.母猪免疫Sowvaccination无需每胎必免。各猪场可根据自己的状况来确定。Don’tneedtovaccinateeverybreedingcycle.Dependsonthefarm.蓝耳阴性场，母猪一年免疫一次IfPRRSnaivethenvaccinatedamsonceperyear.

蓝耳阳性场，每3个月免疫一次IfPRRSpositivethenvaccinateevery3months猪流感或者蓝耳稳定猪场则一年免疫2次。同时免疫其它疫苗。IfSIVorPRRSstablethensemi-annualvaccination.Morediseasethenbetterneedtovaccinate.如何检测通过胎盘感染的仔猪Howtotestpigstoseeifpigletsbecomeinfectedinuterus选取20个不同的仔猪血清Take20serumsfromdifferentpiglets初乳前检测Pre-suckletesting出生时检测。收集颈静脉血或者脐带血。注意：一定是初乳前的血液。Bethereatthebirth.Doajugulartestorcollectumbilicalcordblood.Criticaltotakepre-suckleblood.将每4份血液混成1份，20份样缩减为5份，进行PCR检测病毒。4poolsof5anddoPCRlookingforthevirus.如果阳性则进一步确诊

Ifpositivethendomoretesting.同时检测猪圆环病毒抗体AlsotestantibodiesforPCV2注意反饲！

ManureFeedbackconcerns!猪圆环病毒对反饲的影响？Manurefeedback.WhateffectwouldthishaveonPCV2?病毒血症的母猪或后备母猪通过粪便和鼻分泌物散毒Sowsorgiltsthatareviremiccanshedvirusinfecesandnasalsecretion.反饲未免疫母猪可能导致其感染圆环病毒。FeedbacktoothersowscouldexposethemtoPCV2virusifnovaccineisused猪圆环病毒的免疫方案

PorcineCircovirus-VaccinationProtocols免疫方案-生长猪

VaccinationProtocol–GrowingPigs3周龄时普免-商品苗或自家特制苗

Vaccinateallpigletsat3weeksofagewithCommercialPCVorTissueAutogenousVaccine使用双针型的需要在3周后加强免疫

If2dose–BoosterVaccinatepiglets3weekslaterwithsameproduct根据免疫应答情况，考虑免疫次数和接种时机

Evaluatedosageandtimingofvaccinationasresponseindicates猪蓝耳病(PRRS)PRRSControlOptionsintheUSA:蓝耳病在美国的控制方案蓝耳病区域性净化方案PRRSEliminationandEradication–Regionalcontrol猪群与蓝耳病共存方案PRRS(Decidingtolivewiththediseaseandestablishaprogram)不处理，期待好结果Donothingandhopeforthebest

蓝耳病控制的关键KeystoPRRSControl建立蓝耳病稳定的母猪群（血检阳性、PCR阴性）

CreateaPRRSStableherdwheresowsareserologicallyantibody(Elisa)positivebutarevirus(PCR)negative诊断程序–持续的监测

Diagnosticprogram–Implementtestingprotocol当病毒血症存在时，PCR是确诊母猪、后备猪或其他猪是否是阳性的关键手段

PCRtestiscriticaltodetermineifsows,giltsorpigsarepositiveandwhenviremiaisoccurring确定猪场病毒的毒株

Determinethestrainorstrainspresentonthefarm后备母猪驯化-确保血检阳性、PCR阴性，与母猪保持一致

GiltAcclimitization–Giltsmusthaveuniformstatuswiththesowherd.NeedPRRSserologicpositivetofarmvirusbutPCRnegative猪场蓝耳病的评估

EvaluationofPRRSFarms:评估临床症状，将猪场的情况进行分类

Evaluateclinicalsymptomsandcategorizethestatusofthefarm通过PCR和血清学诊断确定在断奶仔猪中是否存在蓝耳病毒的感染

UsePCRandserologydiagnosticstoconfirmthepresenceorabsenceofPRRSinsowsandweanedpigsPCR检测可以确定免疫时间和剂量

PCRdiagnosticswilldeterminewhichcontrolprogramorvaccinewillberecommendedProtocoltodeterminePRRSStatusSowsTestsowsifclinicalsignsarepresentIfnoclinicalsignsinsowsthennotestingonsowsTestsowsthatareabortingorofffeedTake15samplesandpoolforPCRtestingProtocoltodeterminePRRSStatusPigletsTest30sucklingpiglets15pigsthataretheoldestsucklingpigs15pigsthatare1weekyoungerTesthalfthatarepoorpigsandhalfgoodpigsUsePCRonlytolookforthePRRSvirusElisaantibodiescouldbefromcolostrumorinfectionProtocoltodeterminePRRSStatusNurserypigsTestpigsthathavebeeninthenurseryfor30daysTest10to30pigsTakesomesamplesfrompoorpigsandsomefromgoodpigsTestforPCR(virus)andElisa(antibodies)GiltreplacementsTestgiltsbeforetheyenterthebreedingherdTestforPCR(virus)andElisa(antibodies)Testgiltsthathavebeeninthebreedingherdfor30daysTestforPCR(virus)andElisa(antibodies)PositivePCRfromtestingIsolatePRRSvirusDon’tisolatePRRSvirusTrytoisolatethevirusSequencethevirusComparetopriorfarmstrainsComparetoMLVvaccinethatwillbeusedSequencethevirusfromthePCRComparetopriorfarmstrainsComparetoMLVvaccinethatwillbeused蓝耳病感染母猪群的分类

PRRSSowFarms“StatusClassifications”

发病状态

Outbreak不稳定状态

Unstable稳定状态

Stable阴性

NegativeCycleofPRRSinfectiononsowherds“Outbreak”–lasts4to6weeks“Unstable”–lasts6weeksto2yearstoforever“Stable”–lastsuntilyougetthenextstrainofPRRSorstopvaccinatingandgetPRRSbackIfgetanewstraingobacktothe“Outbreakstatus”Negative–lastsuntilyougetexposedtoaPRRSstrain蓝耳病感染母猪群的分类

PRRSSowFarms“StatusClassifications”1.发病状态Outbreak母猪Sows母猪PCR检测阳性SowsPCRpositive并有临床表现Clinicaldiseasepresent

仔猪

Piglets仔猪PCR检测阳性

PigsPCRpositive有临床症状

Clinicallysickpiglets蓝耳病发病状态“PRRSOutbreakStatus”

有临床症状表现ClinicalDiseasePresent

母猪和仔猪同时出现病毒血症

Viremiaisoccurringinbothsowsandp