医学英语感染病.ppt

Introductiontoinfectiousdiseases,GangXINDepartmentofMicrobiologyandImmunologygxiterms,Infectiology,Infection,Infectiousdiseases,Infectiologist,Infectiousdiseasesarecausedbypathogenicmicroorganisms,suchasbacteria,viruses,parasitesorfungi;thediseasecanbespreaddirectlyorindirectly,formonepersontoanother.,Infectiousdiseases,Communicablediseases,Woundinfection,lunginfection,pathogen,host,Outline,PathogenHostPathogenesisofinfectionClassificationofinfectionClinicalmanifestationsLaboratorydiagnosisofinfectiousdiseasesTreatmentandprevention,pathogen,Typesofpathogens,eu-,Good;well;true,pro-,before,karuo-,nutorcellnucleus,Typesofpathogens,Subcelluar,Prokaryotic,Viruses,prion,Bacterial,chlamydiae,rickettsiae,mycoplasmas,Eukaryotic,Protozoa,fungi,helminthes,arthropods,prion,Aprionisaninfectiousagentcomposedofproteininamisfoldedform,Disease:Bovinespongiformencephalopathy,Madcowdisease(MCD),Viruses,Thetermvirion(pluralvirions)isalsousedtorefertoasingle,stableinfectiveviralparticlethatisreleasedfromthecellandisfullycapableofinfectingothercellsofthesametype,Avirusisasmallinfectiousagentthatcanreplicateonlyinsidethelivingcellsoforganisms.,Bacteria(singular:bacterium),chlamydiae,chlamyd-,mantle,(acloak),Chlamydiainfection,chlamydiaconjunctivitis,ortrachoma,rickettsiae,ThegenusRickettsiaisnamedafterH.T.Ricketts(18711910),whostudiedRockyMountainspottedfever,andeventuallydiedoftyphusafterstudyingthatdisease.,rickets,vitaminDdeficiency,Disease:spottedfever,typhusandscrubtyphus,TickhemolymphcellsinfectedwithR.rickettsii.FromtheCDC.,SymptomsofScrubtyphus,feverheadachemusclepaincoughgastrointestinalsymptomshemorrhagingandintravascularcoagulation.maculopapularrash,eschar（焦痂）,splenomegalyandlymphadenopathiesaretypicalsigns.,Mycoplasma,mykes(fungus)andplasma(formed),Spirochete,syphilis,Saddlenose,Fungi(singular:fungus),Tinea(=ringworm)ofskin,Tineapedis,Tineamanus,Tineacruris,Groupofextremelysmallsinglecell(unicellular)oracellularorganismsthatarefoundinmoistsoilorwater.Theytendtoexistasparasites,livingoffotherlifeforms.,Protos(First)andzoon(animal),protozoa(singular:protozoon),helminthsareworm-likeorganisms(Parasiticworms)thatliveandfeedofflivinghosts,receivingnourishmentandprotectionwhiledisruptingtheirhostsnutrientabsorption,causingweaknessanddisease.,helminths,Helmins=worm,Hookwormsattachedtotheintestinalmucosa.,arthropods,Greekarthron,joint,andpodsfoot,whichtogethermeanjointedfeet”,Pathogenfactors,pathogenicity,virulence,istheabilityofapathogentoproduceaninfectiousdiseaseinanorganism.,Thevirulencefactorsofbacteria,Methodsbywhichbacteriacausedisease,Adhesion,Colonization,Invasion,Immuneresponseinhibitors,Toxins,12345,Thevirulencefactorsofbacteria,Adhesion.Manybacteriamustfirstbindtohostcellsurfaces.Colonization.Somevirulentbacteriaproducespecialproteinsthatallowthemtocolonizepartsofthehostbody.Invasion.Somevirulentbacteriaproduceproteinsthateitherdisrupthostcellmembranesorstimulateendocytosisintohostcells.Thesevirulencefactorsallowthebacteriatoenterhostcellsandfacilitateentryintothebodyacrossepithelialtissuelayersatthebodysurface.Immuneresponseinhibitors.Manybacteriaproducevirulencefactorsthatinhibitthehostsimmunesystemdefenses.Toxins.Manyvirulencefactorsareproteinsmadebybacteriathatpoisonhostcellsandcausetissuedamage.,Methodsbywhichbacteriacausedisease,invasion,minimumlethaldose(MLD)thesmallestamountoftoxinthatwillkillanexperimentalanimal.,Minimuminfectivedose,medianinfectivedose(ID50)theamountofpathogenicmicroorganismsthatwillcauseinfectionin50percentofthetestsubjects.,infectivedosethatamountofpathogenicorganismsthatwillcauseinfectioninsusceptiblesubjects.,Hostfactors,susceptibility,disposition,Immunesystem,Antibody,immunoglobulin,Icebergconceptofinfection,Infectiousdiseasespectrum,Ifalargenumberofindividualsareequallyexposedtoaninfectiousagent,theydonotallrespondinthesamemanner.Infact,theremaybeabroadrangeofresponses:SomedonotbecomeinfectedatallSomebecomeinfectedbutdevelopnosymptomsSomebecomeinfectedanddevelopmildormoderatesymptomsSomebecomeinfectedanddevelopseveresymptomsSomedieasaresultoftheirinfection,Pathogenesisofinfection,Clinicalmanifestationsofinfectiousdiseases,Non-specific,Organsystem-based,FeverAnorexiaFatigueMuscleachesSkinrash,astateofphysicaland/ormentalweakness,Lossofappetite,MaryMallonwasanasymptomaticcarrieroftyphoidfever.Overthecourseofhercareerasacook,sheinfected53people,threeofwhomdied.,Host-PathogenInteractions:SymbioticRelationships,MutualismCommensalismParasitismNeutralism,Asymbioticrelationshipinwhichbothspeciesbenefit,Asymbioticrelationshipinwhichoneorganismderivesbenefitandtheotherisunharmed,Asymbioticrelationshipinwhichonespecies,theparasite,benefitsattheexpenseoftheother,thehost,Thestateofbeingneutral;neutrality,prefix,avariantofsyn-beforeb,p,andm=Together,=Life;livingorganism,airborneinfectiondropletinfectionvector-borneinfectionwaterborneinfectionbloodborneinfection,Modeofinfection,Sneezingcanspreadthefluvirustootherpeople.,airborneinfectiononethatiscontractedbyinhalationofmicroorganismsorsporessuspendedinaironwaterdropletsordustparticles.dropletinfectioninfectionduetoinhalationofrespiratorypathogenssuspendedonliquidparticlesexhaledbysomeonealreadyinfected(dropletnuclei).vector-borneinfectioninfectioncausedbymicroorganismstransmittedfromonehosttoanotherbyacarrier,suchasamosquito,louse,fly,ortick.waterborneinfectioninfectionbymicroorganismstransmittedinwater.,Classificationofinfections1,Typeofthepathogen,Degreeofinvolvement,Bacterial,viral,fungal,parasitic,Local/focal,generalized,Manneracquired,Community,hospital/nosocomial,Classificationofinfections2,Typeofoccurrence,Endogenousvs.exogenous,Autoinfectionvs.cross-infection,Superinfectionvs.reinfection,sepsis,Opportunisticinfection,aninfectioncausedbyaninfectiousagentthatisalreadypresentinthebody,buthaspreviouslybeeninapparentordormant.,aninfectionthatdevelopsfrombacterianormallyoutsidethebodythathavegainedaccesstothebody,aninfectioncausedbyadiseaseagentthatisalreadypresentinthebody,aninfectionbyanorganismthatdoesnotordinarilycausediseasebutbecomespathogenicundercertaincircumstances(e.g.,impairedimmuneresponses).,thetransmissionofacommunicablediseasefromonepersontoanotherbecauseofapoorbarrierprotection,aninfectionfollowingapreviousinfection,especiallywhencausedbymicroorganismsthathavebecomeresistanttotheantibioticsusedearlier,asecondinfectionbythesamemicroorganism,eitherafterrecoveryorduringtheoriginalinfection,12345678,abacterialinfectioninthebloodstreamorbodytissues,Cross-infectionExogenousinfectionEndogenousinfectionOpportunisticinfectionReinfectionSuperinfectionAutoinfectionSepsis,Laboratorydiagnosisofinfectiousdiseases,Goldstandardtest,procedures,MicroscopyandStainingproceduresCultureandsensitivitySerologictest,Stainingprocedures,UrinalysisandfecalysisSpecimensmear(blood,stool)GramStainingZeihl-NeelsonstainKOH(potassiumhydroxide)testforfungi,GramStaining,Gramstainastainingprocedureinwhichmicroorganismsarestainedwithcrystalviolet,treatedwithstrongiodinesolution,decolorizedwithethanol,andcounterstainedwithacontrastingdye;thoseretainingthestainaregram-positive,andthoselosingthestainbutstainingwiththecounterstainaregram-negative.,Zeihl-Neelsenstain,TheZiehl-Neelsenstain,alsoknownastheacid-faststain,wasfirstdescribedbytwoGermandoctors;FranzZiehl(1859-1926),abacteriologistandFriedrichNeelsen(1854-1898),apathologist.Itisa