獸醫(yī)專業(yè)英語揚州大學lesson19

獸醫(yī)專業(yè)英語揚州大學lesson19第1頁/共22頁LessonNineteenFoot-and-MouthDisease第2頁/共22頁NewwordsandphrasesGeographicSerotypeDesignateMortalityMorbidityConvalescenceProtractedRinderpestHusbandrySequelaeLactationPermanentRetardedCompulsoryDemarcationHeterogeneityThresholdpragmaticInseminationSemenAerosolPharyngealEquivocalNeutralizeHomologousPicornavirus第3頁/共22頁TextFoot-and-mouthdiseaseisstillamajorglobalanimalhealthproblem,butitsgeographicdistributionhasbeenshrinkinginrecentyearsascontrolandeliminationprogramshavebeenestablishedinmoreandmorecountries.Sevenserotypesoffoot-and-mouthdiseasevirushavebeenidentifiedbycross-protectionandserologictests,andtheyaredesignatedO,A,C,SAT1,SAT2,SAT3,andAsia1.第4頁/共22頁

Atonetimeoranother,thesevirusesoccurredinmostpartsoftheworld,oftencausingextensiveepidemicsindomesticcattleandswine.Sheepandmanyspeciesofwildlifearealsosusceptible.Mortalityislowbutmorbidityishigh;convalescenceandvirussheddingfromaffectedanimalsmaybeprotractedanditisthesefeaturesthatmakefoot-and-mouthdiseasesoimportant,especiallywhenthevirusisintroducedintocountriespreviouslyfreeof（無…的）disease.第5頁/共22頁Duringthe19thcentury,foot-and-mouthdiseasewaswidelyreportedinEurope,Asia,Africa,andSouthandNorthAmericaandoccurredononeoccasion

（有一次；曾經(jīng)）inAustralia.From1880onward,thecontrolofrinderpest（牛瘟）andtheimprovedhusbandryinthelivestockindustriesinEuropefocusedattentiononfoot-and-mouthdisease.Itssequelaewerefoundtobemoreimportantthantheacuteillness.Indairyherds（奶牛群）,thefebrile(發(fā)熱的)diseaseresultedinthelossofmilkproductionfortherestofthelactationperiod（泌乳期）.第6頁/共22頁Mastitisoftenresultedinapermanentlossofmorethan25%ofmilkproductionandtheretardedgrowthofbeefcattle.Today,manycountrieshaveeithereliminatedfoot-and-mouthdiseasebycompulsory（強制性的）slaughterofinfectedanimalsorhavereduceditsincidencegreatlybyextensivevaccinationprograms.第7頁/共22頁Historically,eachvirustypehasbeenfurthersubtypedonthebasisofquantitativedifferencesincross-protectionandserologictests.Antigenicvariationwithinatypeoccursasacontinuousprocessofantigenicdrift

withoutclear-cut（清晰的）demarcationsbetweensubtypes.Thisantigenicheterogeneityhasimportanteconomicimplicationsforvaccinedevelopmentandselection,asimmunityacquiredthroughinfectionoruseofcurrentvaccinesisstrictlytypespecificand,toalesserdegree,subtypespecific.第8頁/共22頁Difficultyindefiningthethreshold

atwhichanewisolateshouldbegivensubtypestatus

hasalwaysbeenaproblemandcurrentattitudesreflectapragmatic(實用的)approach.Newstrainsarenowcomparedwiththeestablishedvaccinestrainsofcommercialproducers,therebyavoidingthecomplexityofclassifyingnewisolateswithinaneverincreasingcatalogueofsubtypes,

manyofwhichhavelittlerelevancetocurrentproblemsinthefield.第9頁/共22頁Themainrouteofinfectioninruminants(反芻動物)isthroughtheinhalationofdroplets（飛沫）,butingestionofinfectedfood,inoculationwithcontaminatedvaccines,inseminationwithcontaminatedsemen,andcontactwithcontaminatedclothing,veterinaryinstruments,andsooncanallproduceinfection.Inanimalsinfectedviatherespiratorytract,initialviralreplicationoccursinthepharynx（咽）,followedbyviremiaspreadtoothertissuesandorgansbeforetheonsetofclinicaldisease.

inhalation[,inh?‘lei??n]n.吸入；吸入藥劑；inhale[in'heil]vt.吸入；猛吃猛喝vi.吸氣Viraemia[vai‘ri:mi?].病毒血癥；viremia

[vai'ri:mi?]n.〈美〉病毒血癥

ruminant

['ru:min?nt]adj.反芻動物的,沉思的；pharynx

['f?ri?ks]n.[解]咽insemination

[in,semi'nei??n]n.授精,播種；semen

['si:m?n,-men]n.精液instrument

[,instrum?nt]n.器具,儀器樂器；傀儡；正式的文件,文書；第10頁/共22頁Viralexcretioncommencesabout24hourspriortotheonsetofclinicaldiseaseandcontinuesforseveraldays.Aerosols（氣溶膠）producedbyinfectedanimalscontainlargeamountsofvirus,particularlythoseproducedbyswine.Largeamountsofvirusarealsoexcretedinthemilk.Theexcretionofvirusinhightiterindroplets（飛沫）andinmilkhasepidemiologicsignificanceandisimportantforthecontrolofdisease.第11頁/共22頁Foot-and-mouthdiseasevirusmaypersistinthepharynxofsomeanimalsforaprolongedperiodafterrecovery.Incattle,virusmaybedetectableforperiodsupto2yearsafterexposuretoinfection,insheepforabout6months.Viralpersistencedoesnotoccurinswine.Thiscarrierstatehasalsobeenobservedinwildanimals,particularlytheAfricanCapebuffalo（非洲水牛）,whichiscommonlyfoundtobeinfectedwithmorethanoneoftheSATvirustypeseveninareaswherefoot-and-mouthdiseasedoesnotoccurincattle（家牛）.第12頁/共22頁Themechanismsbywhichthevirusproducesapersistentinfection（持續(xù)性感染）inruminantsareunknown.Thevirusispresentinthepharynxinaninfectiousform,for

ifpharyngealfluidsareinoculatedintosusceptibleanimalstheydevelopfoot-and-mouthdisease.Attemptstodemonstratethatcarriercattlecantransmitdiseasebyplacingthemincontactwithsusceptibleanimals

havegivenequivocal(可疑的)results,buttransmissionofvirusfrompersistentlyinfectedAfricanCapebuffalotocattlehasbeenobserved.Recoveryfromclinicalfoot-and-mouthdiseaseiscorrelatedwiththedevelopmentofantibody.第13頁/共22頁TheearlyIgMantibodiesneutralizethehomologoustypeofvirusandmayalsobeeffectiveagainstheterologoustypes.Incontrast,theIgGproducedduringconvalescenceistypespecificand,tovaryingdegrees(從不同的角度來講),subtypespecific.Littleinformationisavailableontheroleofcell-mediatedimmunityinrecoveryfromfoot-and-mouthdisease,butasinotherpicornavirusinfections,ithasbeenassumedtobeofminorimportance.homologous

[h?‘m?l?ɡ?s]adj.相應(yīng)的,類似的,一致的,[生物]同源的；homogeneity[,h?m?ud?e'ni:?ti]同種；同質(zhì)；同次性]heterologous

[,het?‘r?l?ɡ?s]adj.異素[種]的；異種[質(zhì)]的,異要素的heterogeneity[,het?r?ud?i'ni:?ti]n.異質(zhì)性；不均勻性；多相性picornavirus

[pi,k?:n?‘vai?r?s].小核糖核酸病毒pico微小Tovaryingdegrees:

從不同的角度來講第14頁/共22頁Cattlethathaverecoveredfromfoot-and-mouthdiseaseareusuallyimmunetoinfectionwiththesamevirustypeforayearormore,butimmunityisnotconsideredlifelong（縱身的）.Recoveredanimals,however,canbeinfectedimmediatelywithoneoftheothertypesoffoot-and-mouthdiseasevirusanddevelopclinicaldisease.第15頁/共22頁標題和關(guān)鍵詞羊口蹄疫O型和亞洲1型二價滅活疫苗免疫后O型抗體水平的檢測DetectionofTypeOAntibodyLevelsafterImmunizationwithFMDVTypeOandAsia1InactivatedVaccineinSheep關(guān)鍵詞:羊;口蹄疫;滅活疫苗;免疫程序Keywords:sheep;foot-and-mouthdisease;inactivatedvaccine;immuneprocedure第16頁/共22頁摘要:為了探討口蹄疫O型和亞洲1型二價滅活苗免疫接種羊后產(chǎn)生的O型抗體效價,采用不同免疫劑量和不同免疫時間免疫接種羊,應(yīng)用正向間接血凝試驗(IHA),檢測其抗體消長規(guī)律。Abstract:InordertounderstandthetypeOantibodytitersinsheepinoculatedwithFMDtypeOandAsia1inactivatedvaccine,theantibodydynamicswasstudiedbyusingIHAmethodafterwithdifferentdosesandindifferenttime.第17頁/共22頁結(jié)果表明,羔羊母源抗體水平及維持時間與母羊抗體水平呈正相關(guān),有效保護抗體能維持70d左右;首免每只1mL、2mL同時免疫的4組間免疫抗體水平經(jīng)方差分析差異不顯著,首免不能產(chǎn)生有效的保護抗體水平;Theresultsshowedthatlevelsandsustainingtimeoflambmaternalantibodywereproportionaltothoseoftheirparents,theefficientprotectivelevelsofantibodiescouldmaintain70days.Afterthefistvaccination,antibodytitersofsimultaneouslyimmunized4groupswiththedosesof1mLand2mLhadnosignificantdifferenceandcouldnotproduceefficientprotectivelevels.第18頁/共22頁二免2mL、2.5mL不同時間免疫的4組,首免后15d與首免后28d進行二免產(chǎn)生的抗體經(jīng)t檢驗差異極顯著(P<0.01),首免后28d二免的不同劑量組經(jīng)方差分析差異不顯著,有效抗體能維持約170d,首免后15d二免的免疫抗體水平最低;Afterthesecondvaccination,antibodylevelsof4groupsimmunizedindifferenttimewiththedosesof2mLand2.5mLweredifferent.Theantibodylevelsimmunized28daysafterfirstimmunizationwassignificanthigherthanthatimmunized15daysafterfirstimmunization(P<0.01),andtheefficientprotectivelevelcouldmaintain170days.第19頁/共22頁每只三免2mL、3mL的2個劑量組產(chǎn)生的有效抗體均能維持180d,兩組抗體經(jīng)t檢驗差異不顯著(P>0.05)。Afterthethirdimmunization,thedosesof2mLand3mLin2groups,efficientprotectivelevelscouldmaintainhalfayearandtheantibodytitersof2groupswerenotsignificantlydifferent(P>0.05).AnimmuneprocedureforsheepagainstFMDwasrecommendedbasedontheantibodydynamics.第20頁/共22頁

Abstract:InfluenzaAvirusescontinuetocausewidespreadmorbidityandmortality.Thereis