《Measles麻疹》.ppt

MEASLES,FenHuaChen,M.D.,PhD.DepartmentofPediatrics,TheThirdAffiliatedHospitalSunYat-senUniversity,Measlesisanacuteviralinfectioncharacterizedbyamaculopapularrasheruptingsuccessivelyovertheneck,face,body,andextremitisandaccompaniedbyahighfever.,DEFINITION,ETIOLOGY,MeaslesvirusAnRNAvirusofthegenusMorbillivirusinthefamilyofParamyxoviridaeOneserotype,humansonlyhostStableantigenicityRapidlyinactivatedbyheatandlightSurvivalinlowtemperature.,EPIDEMIOLOGY,InfectionsourcesPatientsofacutestageandviralcarriersofatypicalmeaslesTransmissionHighlycontagious,approximately90%ofsusceptiblecontactsacquirethedisease.Respiratorysecretions:maximaldisseminationofvirusoccursbydropletsprayduringtheprodromalperiod(catarrhalstage).Contagiousfrom5daysbeforesymptoms,5daysafteronsetofrashSeasons:inthespring,peakinFeb-May,PATHOGENESISANDPATHOLOGY,PortalofentryRespiratorytractandregionallymphnodesEntersbloodstream(primaryviraemia)monocytephagocytesystemtargetorgans(secondaryviraemia)TargetorgansTheskin;themucousmembranesofthenasopharynx,bronchi,andintestinaltract;andintheconjunctivae,ectResultingIn-1)Koplikspotsandskinrash:serousexudationandproliferationofendothelialcellsofthecapillaries,vasculitis2)Conjunctivis,PATHOGENESISANDPATHOLOGY,3)Laryngitis,croup,bronchitis:generalinflammatoryreaction4)Hyperplasiaoflymphoidtissue:multinucleatedgiantcells(Warthin-Finkeldeyreticuloendothelialgiantcells)maybefound5)Interstitialpneumonitis:Hechtgiantcellpneumonia.6)Bronchopneumonia:duetosecondarybacterialinfections7)Encephalomyelitis:perivasculardemyelinizationoccursinareasofthebrainandspinalcord.8)Subacutesclerosingpanencephalitis(SSPE):degenerationofthecortexandwhitematterwithintranuclearandintracytoplasmicinclusionbodies,CLINICALMANIFESTATION,TypicalManifestation:patientshavnthadmeaslesimmunization,orvaccinefailurewithnormalimmunityorthosehavntusedimmuneglobulin1.Incubationperiod(infectiontosymptoms):6-18days(average10days)2.Prodromalperiod:3-4daysNon-specificsymptoms:fever,malaise,anorexia,headacheClassicaltriad:cough,coryza,conjunctivitis(withphotophobia,lacrimation),CLINICALMANIFESTATION,Enanthem(Koplikspots):Pathognomonicformeasles24-48hrbeforerashappears1mm,grayishwhitedotswithslight,reddishareolaeBuccalmucosa,oppositethelower2ndmolarsfadesoonafterrashonset,CLINICALMANIFESTATION,Koplikspots,CLINICALMANIFESTATION,3.Rashperiod3-4daysExanthem:Erythematous,non-pruritic,maculopapularUpperlateraloftheneck,behindears,hairline,facetrunkarmsandlegsTheseverityofthediseaseisdirectlyrelatedtotheextentandconfluenceoftherash,CLINICALMANIFESTATION,CLINICALMANIFESTATION,CLINICALMANIFESTATION,CLINICALMANIFESTATION,Temperature:RisesabruptlyastherashappearsReaches40orhigherSettlesafter4-5daysifpersists,suspectsecondaryinfectionCoryza,fever,andcough:IncreasinglysevereuptothetimetherashhascoveredthebodyLymphadenopathy(posteriorcervicalregion,mesenteric)splenomegaly,diarrhoea,vomitingChestXray:Maybeabnormal,eveninuncomplicatedcases,CLINICALMANIFESTATION,4.Recoveryperiod3-4daysExanthem:FadesinorderofappearanceBrannydesquamationandbrownishdiscolorationEntireillness10days,CLINICALMANIFESTATION,CLINICALMANIFESTATION,AtypicalManifestation:1.MildmeaslesInpatients:administeredimmuneglobulinproductsduringtheincubationperiodandimmunizedagainstmeasles;ininfants8moLongincubationperiodandshortprodromalphaseMildsymptomNoKoplikspotTherashtendstobefaintNobrannydesquamationandbrownishdiscolorationoccurastherashfadesNocomplicationsandshortcourse,CLINICALMANIFESTATION,2.Severemeasles:Incaseswithmalnutrition,hypoimmunityandsecondaryinfectionPersistenthyperpyrexia,sometimeswithconvulsionsandevencomaExanthem:CompletelycoveredtheskinConfluent,petechiae,ecchymosesThehemorrhagictypeofmeasles(blackmeasles),bleedingmayoccurfromthemouth,nose,orbowel.disseminatedintravascularcoagulation(DIC),CLINICALMANIFESTATION,CLINICALMANIFESTATION,3.Atypicalmeaslessyndroma:Recipientsofkilledmeaslesvirusvaccine,wholatercomeincontactwithwild-typemeaslesvirus.Distinguishedbyhighfever,severeheadache,severeabdominalpain,oftenwithvomiting,myalgias,respiratorysymptoms,pneumoniawithpleuraleffusionExanthem:Firstappearsonthepalms,wrists,soles,andankles,andprogressesinacentripetaldirection.Maculopapularvesicularpurpuricorhemorrhagic.Koplikspotsrarelyappear,CLINICALMANIFESTATION,Atypicalmeaslessyndroma,CLINICALMANIFESTATION,4.MeaslesabsentofrushImmunodepressed,orpassiveimmunizedrecentlycasesandoccasionallyininfants9mowhohaveappreciablelevelsofmaternalantibodyNon-specificityDifficulttodiagnosis,COMPLICATIONS,1.RespiratoryTractLaryngitis,tracheitis,bronchitisduetomeaslesitselfLaryngotrachobronchitis(croup)causeairwayobstructiontorequiretracheostomySecondarypneumoniaimmunocompromised,malnourishedpatients.pneumococcus,groupAStreptococcus,StaphylococcusaureusandHaemophilusinfluenzaetypeB.ExacerbationofTB,COMPLICATIONS,2.Myocarditis3.MalnutritionandVitaminAdeficiency,COMPLICATIONS,4.CNSTheincidenceofencephalomyelitisis1-2/l,000casesofmeaslesOnsetoccurs2-5daysaftertheappearanceoftherashNocorrelationbetweentheseverityoftherashillnessandthatoftheneurologicinvolvementEarlier-directviraleffectinCNSLaterimmuneresponsecausingdemyelinationSignificantmorbidity,permanentsequelaementalretardationandparalysisSubacutesclerosingpanencephalitis(SSPE):extremelyrare,6-10yearsafterinfection.Progressivedementia,fatal.Interactionofhostwithdefectiveformofvirus,LABORATORYEXAMINATION,Isolationofmeaslesvirusfromaclinicalspecimen(e.g.,nasopharynx,urine)SignificantriseinmeaslesIgGbyanystandardserologicassayPositiveserologictestformeaslesIgMantibodyImmunofluorescencedetectsMeaslesantigensMultinucleatedgiantcellsinsmearsofnasalmucosaLowwhitebloodcellcountandarelativelymphocytosisinPBMeaslesencephalitisraisedprotein,lymphocytesinCSF,DIAGNOSIS,characteristicclinicalpicture:MeaslescontactKoplikspotFeaturesoftheskinrashTherelationbetweentheeruptionandfeverLaboratoryconfirmationisrarelyneeded,DIFFERENTIALDIAGNOSIS,Therashofmeaslesmustbedifferentiatedfromthatofrubella;roseolaintantum;enteroviralinfections;scarletfever;anddrugr