IntroductiontoinfectiousdiseasesGangXINDepartmentofMicrobiologyandImmunologyterms單擊此處添加小標題單擊此處添加小標題單擊此處添加小標題添加標題InfectiologyInfectionInfectiousdiseasesInfectiologist打開率35%25%20%10%Infectiousdiseasesarecausedbypathogenicmicroorganisms,suchasbacteria,viruses,parasitesorfungi;thediseasecanbespreaddirectlyorindirectly,formonepersontoanother.InfectiousdiseasesCommunicablediseasesWoundinfectionlunginfectionpathogenhostOutlinePathogenHostPathogenesisofinfectionClassificationofinfectionClinicalmanifestationsLaboratorydiagnosisofinfectiousdiseasesTreatmentandpreventionpathogenTypesofpathogens添加標題karuo-,nutorcellnucleus添加標題eu-,Good;well;true添加標題pro-,before添加標題TypesofpathogensSubcelluar添加標題Prokaryotic添加標題Viruses,prion添加標題Bacterial,chlamydiae,rickettsiae,mycoplasmas添加標題Eukaryotic添加標題Protozoa,fungi,helminthes,arthropods添加標題prionAprionisaninfectiousagentcomposedofproteininamisfoldedformDisease:BovinespongiformencephalopathyMadcowdisease(MCD)VirusesThetermvirion(pluralvirions)isalsousedtorefertoasingle,stableinfectiveviralparticlethatisreleasedfromthecellandisfullycapableofinfectingothercellsofthesametypeAvirusisasmallinfectiousagentthatcanreplicateonlyinsidethelivingcellsoforganisms.Bacteria

(singular:bacterium)chlamydiaechlamyd-,mantle(acloak)Chlamydiainfectionchlamydiaconjunctivitisortrachomarickettsiaerickets,vitaminDdeficiencyThegenusRickettsiaisnamedafterH.T.Ricketts(1871–1910),whostudiedRockyMountainspottedfever,andeventuallydiedoftyphusafterstudyingthatdisease.Disease:spottedfever,typhusandscrubtyphusTickhemolymphcellsinfectedwithR.rickettsii.FromtheCDC.SymptomsofScrubtyphusfeverheadachemusclepaincoughgastrointestinalsymptomshemorrhagingandintravascularcoagulation.maculopapularrash,eschar（焦痂）,splenomegalyandlymphadenopathiesaretypicalsigns.Mycoplasmamykes(fungus)andplasma(formed)SpirochetesyphilisSaddlenoseFungi

(singular:fungus)Tinea(=ringworm

)ofskinTineapedisTineamanusTineacrurisGroupofextremelysmallsinglecell(unicellular)oracellularorganismsthatarefoundinmoistsoilorwater.Theytendtoexistasparasites,livingoffotherlifeforms.Protos(First)andzoon(animal)protozoa

(singular:protozoon)helminthsHelmins=wormhelminthsareworm-likeorganisms(Parasiticworms)thatliveandfeedofflivinghosts,receivingnourishmentandprotectionwhiledisruptingtheirhosts'nutrientabsorption,causingweaknessanddisease.Hookwormsattachedtotheintestinalmucosa.arthropodsGreekarthron,"joint",andpodós"foot",whichtogethermean"jointedfeet”CulexMosquitoAedesMosquitoTicksPathogenfactorsvirulencepathogenicityistheabilityofapathogentoproduceaninfectiousdiseaseinanorganism.Thevirulencefactorsofbacteria

MethodsbywhichbacteriacausediseaseAdhesionColonizationInvasionImmuneresponseinhibitorsToxins12345Thevirulencefactorsofbacteria

Adhesion.Manybacteriamustfirstbindtohostcellsurfaces..Colonization.Somevirulentbacteriaproducespecialproteinsthatallowthemtocolonizepartsofthehostbody.Invasion.Somevirulentbacteriaproduceproteinsthateitherdisrupthostcellmembranesorstimulateendocytosisintohostcells.Thesevirulencefactorsallowthebacteriatoenterhostcellsandfacilitateentryintothebodyacrossepithelialtissuelayersatthebodysurface.Immuneresponseinhibitors.Manybacteriaproducevirulencefactorsthatinhibitthehost'simmunesystemdefenses.Toxins.Manyvirulencefactorsareproteinsmadebybacteriathatpoisonhostcellsandcausetissuedamage.MethodsbywhichbacteriacausediseaseMinimuminfectivedoseinvasionminimumlethaldose

(MLD)thesmallestamountoftoxinthatwillkillanexperimentalanimal.medianinfectivedose

(ID50)theamountofpathogenicmicroorganismsthatwillcauseinfectionin50percentofthetestsubjects.infectivedose

thatamountofpathogenicorganismsthatwillcauseinfectioninsusceptiblesubjects.HostfactorssusceptibilitydispositionImmunesystemAntibody,immunoglobulinIcebergconceptofinfectionInfectiousdiseasespectrumIfalargenumberofindividualsareequallyexposedtoaninfectiousagent,theydonotallrespondinthesamemanner.Infact,theremaybeabroadrangeofresponses:SomedonotbecomeinfectedatallSomebecomeinfectedbutdevelopnosymptomsSomebecomeinfectedanddevelopmildormoderatesymptomsSomebecomeinfectedanddevelopseveresymptomsSomedieasaresultoftheirinfectionPathogenesisofinfectionClinicalmanifestationsofinfectiousdiseasesOrgansystem-basedNon-specificFeverAnorexiaFatigueMuscleachesSkinrashLossofappetiteastateofphysicaland/ormentalweaknessMaryMallonwasanasymptomaticcarrieroftyphoidfever.Overthecourseofhercareerasacook,sheinfected53people,threeofwhomdied.Host-PathogenInteractions:SymbioticRelationshipsMutualismCommensalismParasitismNeutralismAsymbioticrelationshipinwhichbothspeciesbenefitAsymbioticrelationshipinwhichoneorganismderivesbenefitandtheotherisunharmedAsymbioticrelationshipinwhichonespecies,theparasite,benefitsattheexpenseoftheother,thehostThestateofbeingneutral;neutralityprefix,avariantofsyn-beforeb,p,andm=Together

=Life;livingorganismairborneinfection

dropletinfectionvector-borneinfectionwaterborneinfectionbloodborneinfectionModeofinfectionSneezingcanspreadthefluvirustootherpeople.airborneinfection

onethatiscontractedbyinhalationofmicroorganismsorsporessuspendedinaironwaterdropletsordustparticles.dropletinfection

infectionduetoinhalationofrespiratorypathogenssuspendedonliquidparticlesexhaledbysomeonealreadyinfected(dropletnuclei).vector-borneinfectioninfectioncausedbymicroorganismstransmittedfromonehosttoanotherbyacarrier,suchasamosquito,louse,fly,ortick.waterborneinfectioninfectionbymicroorganismstransmittedinwater.Classificationofinfections1TypeofthepathogenDegreeofinvolvementBacterial,viral,fungal,parasiticLocal/focal,generalizedManneracquiredCommunity,hospital/nosocomialClassificationofinfections2Autoinfectionvs.cross-infectionTypeofoccurrenceSuperinfectionvs.reinfectionOpportunisticinfectionEndogenousvs.exogenoussepsisaninfectioncausedbyaninfectiousagentthatisalreadypresentinthebody,buthaspreviouslybeeninapparentordormant.aninfectionthatdevelopsfrombacterianormallyoutsidethebodythathavegainedaccesstothebodyaninfectioncausedbyadiseaseagentthatisalreadypresentinthebody

aninfectionbyanorganismthatdoesnotordinarilycausediseasebutbecomespathogenicundercertaincircumstances(e.g.,impairedimmuneresponses).thetransmissionofacommunicablediseasefromonepersontoanotherbecauseofapoorbarrierprotectionaninfectionfollowingapreviousinfection,especiallywhencausedbymicroorganismsthathavebecomeresistanttotheantibioticsusedearlierasecondinfectionbythesamemicroorganism,eitherafterrecoveryorduringtheoriginalinfection12345678abacterialinfectioninthebloodstreamorbodytissuesCross-infection01Exogenousinfection02Endogenousinfection03Opportunisticinfection04Reinfection05Superinfection06Autoinfection07Sepsis08LaboratorydiagnosisofinfectiousdiseasesproceduresGoldstandardtestMicroscopyandStainingproceduresCultureandsensitivitySerologictestStainingproceduresUrinalysisandfecalysisSpecimensmear(blood,stool)GramStainingZeihl-NeelsonstainKOH(potassiumhydroxide)testforfungiGramstain

astainingprocedureinwhichmicroorganismsarestainedwithcrystalviolet,treatedwithstrongiodinesolution,decolorizedwithethanol,andcounterstainedwithacontrastingdye;thoseretainingthestainaregram-positive,andthoselosingthestainbutstainingwiththecounterstainaregram-negative.單擊此處添加小標題GramStainingTheZiehl-Neelsenstain,alsoknownastheacid-faststain,wasfirstdescribedbytwoGermandoctors;FranzZiehl(1859-1926),abacteriologistandFriedrichNeelsen(1854-1898),apathologist.Itisaspecialbacteriological