禽流感与人类流感病毒

AvianandHumanInfluenza

禽流感與人類流感病毒新光醫院感染科張藏能Influenza:AHistoricalPerspectiveFirstwell-recordedpandemicoccurredin1580OriginatedinAsiaandsubsequentlyspreadtoAfrica,Europe,andAmerica.In1932,influenzaviruswasfirstidentifiedinthelaboratoryasthecausativeagentresponsiblefortheseperiodicoutbreaksofrespiratoryillness.OrganismorInfectionTotalno.ofpatientsN=200(%)Rinovirus105(53)Coronavirus14(7.0)Influenza12(6.0)Parainfluenza7(4.0)RSV4(2.0)Adenovirus2(1.0)Enterovirus1(0.5)C.pneumoniae1(0.5)M.pneumoniae1(0.5)S.pneumoniae1(0.5)Doublevirusinfection10(5.0)Viralandbacterialinfection6(3.0)EtiologyoftheCommonCold

prospectivestudyduring10months

MakelaMJ.JClinMicro1998流感(Influenza)的真面目流感(Influenza)與感冒(cold)是完全不同的疾病。流感是一種可怕的疾病，它曾在1918年度造成全球超過2000萬人死亡。流感是一種年年發生的疾病。流感造成的社會成本是其他疾病無法比擬的。PathogenTotal(%)N=267Bacterialpathogens144(54)S.pneumonia129(48)H.influenza20(7)Atypicalpathogens60(22)C.pnuemoniae35(13)M.pnuemonia9(3)Legionella9(3)Virus62(23)InfluenzaA50(19)InfluenzaB2(1)RSV11(4)

CommunityacquiredpnuemoniainadultsadmittedtohospitalLimWSThorax2001流行感冒病毒依其基因分為A型、B型及C型A型流行感冒病毒主要流行於人類、家禽、豬、馬等B型及C型流行感冒病毒則迄今只發現於人類間流行流感病毒的分類Influenzaevirus:epidemiologyAgvariation:Hemagglutinin,Neuraminidase.Agdrift(抗原飄變):minorchange&occureveryyear.TypeAandBAgshift(抗原移變):newvirus,heraldpandemic(全面流行)influenzae.1918H1N1----1957H2N2.OnlyTypeAInfluenzaViruses:StructureEnvelopeproteins Hemagglutinin(HA):functionsin attachmentandpenetration Neuraminidase(NA):cleavessialicacidfromglycoconjugates;facilitateselutionofprogenyvirionsfrominfectedcells

M2:functionsinuncoatingandvirusmaturationTheInfluenzaAVirusPrimaryAgdeterminant-glcoproteinHemagglutinin:H1-15Neuraminidase:N1-9.InfluenzaPandemic:origin?1918pandemicwasassociatedwithanunusuallyhighcase-fatalityrateinyounghealthyadults.Theoriginofthe1918Spanishinfluenzavirusisstillaworkinprogress.Gradualadaptationofavianinfluenzavirusestohumantransmission.Thereissomeevidencethatthisoccurredinthe1918H1N1pandemic.SequenceandphylogeneticanalysisoftheHA,NA,andgenesegmentsofthesesamplessuggeststhatanavianinfluenzaviruswastransmittedtohumansandpigs,developingseparatelineagessometimebefore1918.Itseemstobemoreakintothe"birdflu"thatemergedinHongKongin1997.Webster,RobertG.Science.293(5536):1773,2001PersonswithIncreasedRiskforComplicationsfromInfluenza≥50yearsofageChronicpulmonaryorcardiovasculardiseaseChronicmetabolicdisease,renaldysfunction,hemoglobinopathies,immunosuppressionChildren&teens(6mo.-18yr.)takingaspirinWomeninthe2ndor3rdtrimestersofpregnancy

InfluenzaBPredominantInfluenzaAPredominantDistributionofInfluenzaIsolatesbySubtypeSeptember29,2002–June13,2003A:78%B:22%A:77%B:23%A:49%B:51%A:42%B:58%*A:22%B:78%A:72%B:28%A:41%B:59%A:86%B:14%A:57%B:43%InfluenzaVirusesIsolatedby

WHO/NREVSSCollaboratingLaboratories

2002-0358%A42%B73%A(H1)27%A(H3N2)InfluenzaevirusIncubation:1-3daysdependingontheinitialviralinoculum.Majorfocusofinfection:ciliatedrespiratoryepithelium.Sinusitis(鼻竇炎)，OtitisMedia(中耳炎)Bronchitis(支氣管炎)，Pneumonia(肺炎)，有下列疾病時會更加重症狀:

Asthma(哮喘病)，COPD(慢性阻塞性肺病)

流感感染的併發症SystemicComplicationsMyositis(肌炎),Myocarditis(心肌炎)，Encephalitis(腦炎)胸部併發症LaboratoryDiagnosisDetectionofAntigen

-arapiddiagnosiscanbemadebythedetectionofinfluenzaantigenfromnasopharyngealaspiratesandthroatwashingsbyIFTandELISAVirusIsolation

-virusmaybereadilyisolatedfromnasopharyngealaspiratesandthroatswabs.Serology

-aretrospectivediagnosismaybemadebyserology.CFTmostwidelyused.HAIandEIAmaybeusedtogiveatype-specificdiagnosisRT-PCR禽流感avianinfluenzavirus

bird-flu(FowlPlague)雞瘟TransmissionofthediseasetohumansremainsamajorconcernAvianInfluenzaCausedbyOrthomyxoviridae,typeA(multiplestrandedRNAvirus)Multiplespikeglycoproteins— Hemagglutinin(15) Neuraminidase(9)VirusesclassifiedoncombinationofHandNtypes(eg.H5N2)Recombinationoccursverycommonlyby“shiftanddrift”Subdivisionsofvirustypesonbasisofpathogenicity:LowpathogenicityHighpathogenicityPathogenicitydeterminedbylivebirdinoculationsorviralgenomicsequencinganalysisEstablishingviralH&N/pathotypeveryimportantinoutbreakresponseBirdscangetall15Hand9NtypesoftypeAInfluenzaHighpathogenicity:alwaysoftheH5orH7subtypes,butnotallH5andH7virusesarehighlypathogenicPathogenesisIncubationPeriod:3-14daysHighlycontagious(100%)LowPath–lowmortality,recoverin3weeksHighPath–95%mortalitywithin24hrsHPAI-clinicalsignsClinicalsignsDiseaseinmostspeciesofbirds--inUS,mostinchickensandturkeysRepiratorydisease—snicking,sneezing,lacrimation,sinusitis,etc.edema,hemorrhages,cyanosisofcombsandwattlesHighmortalityNeurologicdisease(insomecases)MaybesuddenmortalitywithoutsignificantclinicalsignsChangeineggshellpigmentation,shell-lesseggsproducedEdematous,cyanoticcombandwattlesofachicken禽流感

AvianInfluenza目前禽流感停留在禽鳥傳染病的階段，偶有人類因為密切接觸禽鳥，遭大量病毒感染，但人和人之間不會互相傳染。AvianInfluenzainHongKong1997:

casepresentOn9May1997,apreviouslyhealthy3-year-oldboy,whowasaresidentofHongKong,oftenplayedwithpetducks,developedasorethroat,drycough,andfever.Hospitalizedon15May---remarkableforleukopenia(WBC:2000)----nextday,hedevelopedprogressiverespiratorydistressassociatedwithhypoxemia.-----diedon21Maywithseveralcomplications,includingrespiratoryfailure,renalfailure,anddisseminatedintravascularcoagulopathyAvianInfluenzainHongKong1997:

casepresentFinaldiagnosis:Reyesyndrome,acuteinfluenzapneumonia,andrespiratorydistresssyndromeInfluenzaA(H5N1)viruswasisolatedfromatrachealaspiratecollectedonMay19.AvianInfluenzainHongKong1997

A型流行性感冒H5N1香港一九九七年出現十八個病例，其中六例死亡，死亡率為33.3％病徵及發病初期，與一般流感類似，但發燒可高至41°C，且較一般流感容易影響肝功能，也較易引致淋巴細胞減少及呼吸衰竭，甚至多器官功能衰竭而死亡。死者多是平時身體頗健康的成年人。AvianInfluenzainHongKong1999

H9N2

SeveralcasesofhumaninfectionwithavianH9N2virusoccurredinHongKongandSouthernChinain1999.ThediseasewasmildandallpatientsmadeacompleterecoveryAgain,therewasnoevidenceofreassortment南韓爆發禽流感(H5N1)

上萬雞隻暴斃

2003-12-16西部的山口縣官員周一表示，當地一家禽農場約有6,000雞隻已因感染禽流感而病死。越南禽流感嚴重

2004-1-1