急性胃腸炎病毒e課件

GastrointestinalVirusesItisthoughtthatvirusesareresponsibleforupto3/4ofallinfectivediarrhoeas.1Viralgastroenteritisisthesecondmostcommonviralillnessafterupperrespiratorytractinfection.2Indevelopingcountries,viralgastroenteritisisamajorkillerofinfantswhoareundernourished.Rotavirusesareresponsibleforhalfamilliondeathsayear.3Manydifferenttypesofvirusesarefoundinthegutbutonlysomeareassociatedwithgastroenteritis.4ViralGastroenteritisAssociatedwithgastroenteritisRotavirusesAdenoviruses4041Caliciviruses嵌杯病毒NorwalklikevirusesorSRSV(SmallRoundStructuredViruses)AstrovirusesSRV(SmallRoundViruses)CoronavirusesTorovirusesFoundinthegut,notnormallyassociatedwithgastroenteritisPolio1CoxsackieA2CoxsackieB3Echo4Enteroviruses68-715HepatitisA6HepatitisE7Adenoviruses1-398Reoviruses9FoundinthegutasopportunisticinfectionCMVHSVVZVHIVGastrointestinalVirusesVirusGenomeTypicaldiseaseincubationDurationRotaviruses:GroupA,B,Cds-segmentedRNAMajorcauseofdiarrheainchildren1-3days24-56h5-8days3-7daysCalicivirusesNorwalkagentsssRNAInfectsadultsandchildrenEpidemicviralgastroenteritis1-3days18-24h1-3days12-48hEAd40,41LineardsRNAdiarrheainchildren7-8days8-12dAstrovirus+ssRNAInfectsmainlychildrenandelderly1-4days1-4dRotavirusA;Adenovirus40,41;CoxsackieA24virusInfants:Norwalkvirus;Calicivirus嵌杯病毒;astrovirus;RotavirusB;Reovirus.Infants,children,andadultsGastrointestinalVirusesHumanRotavirusImportantCharacteristicsnmround,doubleshelled,enclosingagenomeof11segmentsofdoublestrandedRNA.GroupsofRotavirusesGroupAsubtypes1,2,3,4(mainhumanpathogens)

(Further7subtypes)alsoinfectanimals(monkey,calf,mouse)GroupBInfectspigsandrats

FoundtocauseextensiveoutbreaksinChinainpastdecadeGroupCInfectsPigs(OccasionallyMan)GroupDInfectsbirdsGroupEInfectspigsEssentiallyaningestiondisease(faecal-oralroute)Incubationisshort:1to3daysIllness:Suddenonsetwaterydiarrhoea,withorwithoutvomiting.Maylastupto6days(orlongerifimmunocompromised).Thediseaseisselflimiting.Complications:Dehydrationmayresult,thiscanbesevereandlifethreateninginyoungchildren.PathogenesisGroupA:Mainpathogenofinfantilediarrhea01GroupB:Causeepidemicadultdiarrhea02GroupC:Causehumanoranimalsporadicdiarrhea03PathogenesisPAGEofRNAsegments,ELISAIEM,Cellculture,LatexagglutinationPCR020304050601Lab.DiagnosisImmunity:sIgATreatmenttreatmentofdehydrationbyoraland/orintravenousfluidsandelectrolytesPreventionNonspecificfactors:improvedhygiene,education,cleanwater

Specific-Breastfeedinghelpstoprovidepassiveimmunityinthenewborn(frommaternalantibodies),

Vaccinationisstillexperimental.0102EntericAdenovirusesNakedDNAviruses,75nmindiameter.Fastidiousentericadenovirustypes40and41areassociatedwithgastroenteritis.Associatedwithcasesofendemicgastroenteritis,usuallyinyoungchildrenandneonates.Cancauseoccasionaloutbreaks.Possiblythesecondmostcommonviralcauseofgastroenteritis(7-15%ofallendemiccases).SimilardiseasetorotavirusesMostpeoplehaveantibodiesagainstentericadenovirusesbytheageofthree.DiagnosedbyelectronmicroscopyorbythedetectionofadenovirusantigensinfaecesbyELISAorotherassays.SmallRNAviruses,namedbecauseofstar-shapedsurfacemorphology,28nmindiameter.Responsibleforupto10%ofcasesofgastroenteritis.Mostpeoplehaveantibodiesbytheageofthree.Associatedwithcasesofendemicgastroenteritis,usuallyinyoungchildrenandneonates.Cancauseoccasionaloutbreaks.Similardiseasetorotaandadenoviruses.Diagnosedbyelectronmicroscopyonly,oftenverydifficultbecauseofsmallsize.AstrovirusesDiagnosedbyelectronmicroscopyonly,oftendifficulttodiagnosebecauseofsmallsize.04Majorityofchildrenhaveantibodiesagainstcalicivirusesbytheageofthree.05SmallRNAviruses,characteristicsurfacemorphologyconsistingofhollows.particles35nmindiameter.01LikeNorwalktypeviruses,vomitingistheprominentfeatureofdisease.03Associatedmainlywithepidemicoutbreaksofgastroenteritis,althoughoccasionallyresponsibleforendemiccases.02CalicivirusesNorwalk-like

VirusesSmallRNAviruses,withraggedsurface,35nmindiameter,nowclassifiedascaliciviruses.Alwaysassociatedwithepidemicoutbreaksofgastroenteritis,adultsmorecommonlyaffectedthanchildren.Associatedwithconsumptionofshellfishandothercontaminatedfoods.Aerosolspreadpossibleaswellasfaecal-oralspread.Alsonamed"wintervomitingdisease",withvomitingbeingtheprominentsymptom,diarrhoeausuallymild.Antibodiesacquiredlaterinlife,intheUS,only50%ofadultsareseropositivebytheageof50.DiagnosisismadebyelectronmicroscopyandbyPCR.RNAviruseswithacrown-likeappearanceNotconvincingassociatedwithgastroenteritisatpresentCoronaviruses01Smallvirus-likeparticleswithasmoothsurface,22-28nmindiameterMaypossiblybeparvoviruses,enteroviruses,orcubicba