GastrointestinalViruses第一頁(yè)，共二十六頁(yè)。ViralGastroenteritisItisthoughtthatvirusesareresponsibleforupto3/4ofallinfectivediarrhoeas.Viralgastroenteritisisthesecondmostmonviralillnessafterupperrespiratorytractinfection.Indevelopingcountries,viralgastroenteritisisamajorkillerofinfantswhoareundernourished.Rotavirusesareresponsibleforhalfamilliondeathsayear.Manydifferenttypesofvirusesarefoundinthegutbutonlysomeareassociatedwithgastroenteritis.

第二頁(yè)，共二十六頁(yè)。AssociatedwithgastroenteritisRotavirusesAdenoviruses4041Caliciviruses嵌杯病毒NorwalklikevirusesorSRSV(SmallRoundStructuredViruses)AstrovirusesSRV(SmallRoundViruses)CoronavirusesToroviruses第三頁(yè)，共二十六頁(yè)。Foundinthegut,notnormallyassociatedwithgastroenteritisPolioCoxsackieACoxsackieBEchoEnteroviruses68-71HepatitisAHepatitisEAdenoviruses1-39Reoviruses第四頁(yè)，共二十六頁(yè)。FoundinthegutasopportunisticinfectionCMVHSVVZVHIV第五頁(yè)，共二十六頁(yè)。GastrointestinalVirusesVirusGenomeTypicaldiseaseincubationDurationRotaviruses:GroupA,B,Cds-segmentedRNAMajorcauseofdiarrheainchildren1-3days24-56h5-8days3-7daysCalicivirusesNorwalkagentsssRNAInfectsadultsandchildrenEpidemicviralgastroenteritis1-3days18-24h1-3days12-48hEAd40,41LineardsRNAdiarrheainchildren7-8days8-12dAstrovirus+ssRNAInfectsmainlychildrenandelderly1-4days1-4d第六頁(yè)，共二十六頁(yè)。GastrointestinalVirusesInfants:RotavirusA;Adenovirus40,41;CoxsackieA24virusInfants,children,andadultsNorwalkvirus;Calicivirus嵌杯病毒;astrovirus;RotavirusB;Reovirus.第七頁(yè)，共二十六頁(yè)。HumanRotavirus第八頁(yè)，共二十六頁(yè)。ImportantCharacteristics70nmround,doubleshelled,enclosingagenomeof11segmentsofdoublestrandedRNA.第九頁(yè)，共二十六頁(yè)。第十頁(yè)，共二十六頁(yè)。GroupsofRotavirusesGroupAsubtypes1,2,3,4(mainhumanpathogens)

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

FoundtocauseextensiveoutbreaksinChinainpastdecadeGroupCInfectsPigs(OccasionallyMan)GroupDInfectsbirdsGroupEInfectspigs第十一頁(yè)，共二十六頁(yè)。第十二頁(yè)，共二十六頁(yè)。PathogenesisEssentiallyaningestiondisease(faecal-oralroute)Incubationisshort:1to3daysIllness:Suddenonsetwaterydiarrhoea,withorwithoutvomiting.Maylastupto6days(orlongerifimmunopromised).Thediseaseisselflimiting.Complications:Dehydrationmayresult,thiscanbesevereandlifethreateninginyoungchildren.第十三頁(yè)，共二十六頁(yè)。PathogenesisGroupA:MainpathogenofinfantilediarrheaGroupB:CauseepidemicadultdiarrheaGroupC:Causehumanoranimalsporadicdiarrhea第十四頁(yè)，共二十六頁(yè)。第十五頁(yè)，共二十六頁(yè)。Immunity:sIgALab.DiagnosisIEM,Cellculture,PAGEofRNAsegments,PCRLatexagglutinationELISA第十六頁(yè)，共二十六頁(yè)。Treatmenttreatmentofdehydrationbyoraland/orintravenousfluidsandelectrolytes第十七頁(yè)，共二十六頁(yè)。PreventionNonspecificfactors:improvedhygiene,education,cleanwater

Specific-Breastfeedinghelpstoprovidepassiveimmunityinthenewborn(frommaternalantibodies),

Vaccinationisstillexperimental.第十八頁(yè)，共二十六頁(yè)。EntericAdenovirusesNakedDNAviruses,75nmindiameter.Fastidiousentericadenovirustypes40and41areassociatedwithgastroenteritis.Associatedwithcasesofendemicgastroenteritis,usuallyinyoungchildrenandneonates.Cancauseoccasionaloutbreaks.Possiblythesecondmostmonviralcauseofgastroenteritis(7-15%ofallendemiccases).SimilardiseasetorotavirusesMostpeoplehaveantibodiesagainstentericadenovirusesbytheageofthree.DiagnosedbyelectronmicroscopyorbythedetectionofadenovirusantigensinfaecesbyELISAorotherassays.第十九頁(yè)，共二十六頁(yè)。AstrovirusesSmallRNAviruses,namedbecauseofstar-shapedsurfacemorphology,28nmindiameter.Associatedwithcasesofendemicgastroenteritis,usuallyinyoungchildrenandneonates.Cancauseoccasionaloutbreaks.Responsibleforupto10%ofcasesofgastroenteritis.Similardiseasetorotaandadenoviruses.Mostpeoplehaveantibodiesbytheageofthree.Diagnosedbyelectronmicroscopyonly,often

verydifficultbecauseofsmallsize.第二十頁(yè)，共二十六頁(yè)。CalicivirusesSmallRNAviruses,characteristicsurfacemorphologyconsistingofhollows.particles35nmindiameter.Associatedmainlywithepidemicoutbreaksofgastroenteritis,althoughoccasionallyresponsibleforendemiccases.LikeNorwalktypeviruses,vomitingistheprominentfeatureofdisease.Majorityofchildrenhaveantibodiesagainstcalicivirusesbytheageofthree.Diagnosedbyelectronmicroscopyonly,oftendifficulttodiagnosebecauseofsmallsize.第二十一頁(yè)，共二十六頁(yè)。Norwalk-like

VirusesSmallRNAviruses,withraggedsurface,35nmindiameter,nowclassifiedascaliciviruses.Alwaysassociatedwithepidemicoutbreaksofgastroenteritis,adultsmoremonlyaffectedthanchildren.Associatedwithconsumptionofshellfishandothercontaminatedfoods.Aerosolspreadpossibleaswellasfaecal-oralspread.Alsonamed"wintervomitingdisease",withvomitingbeingtheprominentsymptom,diarrhoeausuallymild.Antibodiesacquiredlaterinlife,intheUS,only50%ofadultsareseropositivebytheageof50.DiagnosisismadebyelectronmicroscopyandbyPCR.第二十二頁(yè)，共二十六頁(yè)。第二十三頁(yè)，共二十六頁(yè)。OtherPossibleDiarrhoealVirusesCoronavirusesRNAviruseswithacrown-likeappearanceNotconvincingassociatedwithgastroenteritisatpresentSmallRoundVirusesSmallvirus-likeparticleswithasmoothsurface,22-28nmindiameterMaypossiblybeparvoviruses,enteroviruses,orcubicbacteriophagesOccasionallyseeninthefaecesofendemicorepidemiccasesofgastroenteritis第二十四頁(yè)，共二十六頁(yè)。GastrointestinalVirusesVirusGenomeTypicaldiseaseincubationDurationRotaviruses:GroupA,B,Cds-segmentedRNAMajorcauseofdiarrheainchildren1-3days24-56h5-8days3-7daysCalicivirusesNorwal