急性胃腸炎病毒e課件

GastrointestinalViruses第1頁(yè)，共26頁(yè)。ViralGastroenteritisItisthoughtthatvirusesareresponsibleforupto3/4ofallinfectivediarrhoeas.Viralgastroenteritisisthesecondmostcommonviralillnessafterupperrespiratorytractinfection.Indevelopingcountries,viralgastroenteritisisamajorkillerofinfantswhoareundernourished.Rotavirusesareresponsibleforhalfamilliondeathsayear.Manydifferenttypesofvirusesarefoundinthegutbutonlysomeareassociatedwithgastroenteritis.

第2頁(yè)，共26頁(yè)。AssociatedwithgastroenteritisRotavirusesAdenoviruses4041Caliciviruses嵌杯病毒NorwalklikevirusesorSRSV(SmallRoundStructuredViruses)AstrovirusesSRV(SmallRoundViruses)CoronavirusesToroviruses第3頁(yè)，共26頁(yè)。Foundinthegut,notnormallyassociatedwithgastroenteritisPolioCoxsackieACoxsackieBEchoEnteroviruses68-71HepatitisAHepatitisEAdenoviruses1-39Reoviruses第4頁(yè)，共26頁(yè)。FoundinthegutasopportunisticinfectionCMVHSVVZVHIV第5頁(yè)，共26頁(yè)。GastrointestinalVirusesVirusGenomeTypicaldiseaseincubationDurationRotaviruses:GroupA,B,Cds-segmentedRNAMajorcauseofdiarrheainchildren1-3days24-56h5-8days3-7daysCalicivirusesNorwalkagentsssRNAInfectsadultsandchildrenEpidemicviralgastroenteritis1-3days18-24h1-3days12-48hEAd40,41LineardsRNAdiarrheainchildren7-8days8-12dAstrovirus+ssRNAInfectsmainlychildrenandelderly1-4days1-4d第6頁(yè)，共26頁(yè)。GastrointestinalVirusesInfants:RotavirusA;Adenovirus40,41;CoxsackieA24virusInfants,children,andadultsNorwalkvirus;Calicivirus嵌杯病毒;astrovirus;RotavirusB;Reovirus.第7頁(yè)，共26頁(yè)。HumanRotavirus第8頁(yè)，共26頁(yè)。ImportantCharacteristics70nmround,doubleshelled,enclosingagenomeof11segmentsofdoublestrandedRNA.第9頁(yè)，共26頁(yè)。第10頁(yè)，共26頁(yè)。GroupsofRotavirusesGroupAsubtypes1,2,3,4(mainhumanpathogens)

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

FoundtocauseextensiveoutbreaksinChinainpastdecadeGroupCInfectsPigs(OccasionallyMan)GroupDInfectsbirdsGroupEInfectspigs第11頁(yè)，共26頁(yè)。第12頁(yè)，共26頁(yè)。PathogenesisEssentiallyaningestiondisease(faecal-oralroute)Incubationisshort:1to3daysIllness:Suddenonsetwaterydiarrhoea,withorwithoutvomiting.Maylastupto6days(orlongerifimmunocompromised).Thediseaseisselflimiting.Complications:Dehydrationmayresult,thiscanbesevereandlifethreateninginyoungchildren.第13頁(yè)，共26頁(yè)。PathogenesisGroupA:MainpathogenofinfantilediarrheaGroupB:CauseepidemicadultdiarrheaGroupC:Causehumanoranimalsporadicdiarrhea第14頁(yè)，共26頁(yè)。第15頁(yè)，共26頁(yè)。Immunity:sIgALab.DiagnosisIEM,Cellculture,PAGEofRNAsegments,PCRLatexagglutinationELISA第16頁(yè)，共26頁(yè)。Treatmenttreatmentofdehydrationbyoraland/orintravenousfluidsandelectrolytes第17頁(yè)，共26頁(yè)。PreventionNonspecificfactors:improvedhygiene,education,cleanwater

Specific-Breastfeedinghelpstoprovidepassiveimmunityinthenewborn(frommaternalantibodies),

Vaccinationisstillexperimental.第18頁(yè)，共26頁(yè)。EntericAdenovirusesNakedDNAviruses,75nmindiameter.Fastidiousentericadenovirustypes40and41areassociatedwithgastroenteritis.Associatedwithcasesofendemicgastroenteritis,usuallyinyoungchildrenandneonates.Cancauseoccasionaloutbreaks.Possiblythesecondmostcommonviralcauseofgastroenteritis(7-15%ofallendemiccases).SimilardiseasetorotavirusesMostpeoplehaveantibodiesagainstentericadenovirusesbytheageofthree.DiagnosedbyelectronmicroscopyorbythedetectionofadenovirusantigensinfaecesbyELISAorotherassays.第19頁(yè)，共26頁(yè)。AstrovirusesSmallRNAviruses,namedbecauseofstar-shapedsurfacemorphology,28nmindiameter.Associatedwithcasesofendemicgastroenteritis,usuallyinyoungchildrenandneonates.Cancauseoccasionaloutbreaks.Responsibleforupto10%ofcasesofgastroenteritis.Similardiseasetorotaandadenoviruses.Mostpeoplehaveantibodiesbytheageofthree.Diagnosedbyelectronmicroscopyonly,often

verydifficultbecauseofsmallsize.第20頁(yè)，共26頁(yè)。CalicivirusesSmallRNAviruses,characteristicsurfacemorphologyconsistingofhollows.particles35nmindiameter.Associatedmainlywithepidemicoutbreaksofgastroenteritis,althoughoccasionallyresponsibleforendemiccases.LikeNorwalktypeviruses,vomitingistheprominentfeatureofdisease.Majorityofchildrenhaveantibodiesagainstcalicivirusesbytheageofthree.Diagnosedbyelectronmicroscopyonly,oftendifficulttodiagnosebecauseofsmallsize.第21頁(yè)，共26頁(yè)。Norwalk-like

VirusesSmallRNAviruses,withraggedsurface,35nmindiameter,nowclassifiedascaliciviruses.Alwaysassociatedwithepidemicoutbreaksofgastroenteritis,adultsmorecommonlyaffectedthanchildren.Associatedwithconsumptionofshellfishandothercontaminatedfoods.Aerosolspreadpossibleaswellasfaecal-oralspread.Alsonamed"wintervomitingdisease",withvomitingbeingtheprominentsymptom,diarrhoeausuallymild.Antibodiesacquiredlaterinlife,intheUS,only50%ofadultsareseropositivebytheageof50.DiagnosisismadebyelectronmicroscopyandbyPCR.第22頁(yè)，共26頁(yè)。第23頁(yè)，共26頁(yè)。OtherPossibleDiarrhoealVirusesCoronavirusesRNAviruseswithacrown-likeappearanceNotconvincingassociatedwithgastroenteritisatpresentSmallRoundVirusesSmallvirus-likeparticleswithasmoothsurface,22-28nmindiameterMaypossiblybeparvoviruses,enteroviruses,orcubicbacteriophagesOccasionallyseeninthefaecesofendemicorepidemiccasesofgastroenteritis第24頁(yè)，共26頁(yè)。GastrointestinalVirusesVirusGenomeTypicaldiseaseincubationDurationRotaviruses:GroupA,B,Cds-segmentedRNAMajorcauseofdiarrheainchildren1-3days24-56h5-8