医学英语-感染病.ppt

Introductiontoinfectiousdiseases GangXINDepartmentofMicrobiologyandImmunologygxin terms 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 1871 1910 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 receivingnourishmentandprotectionwhiledisruptingtheirhosts nutrientabsorption causingweaknessanddisease helminths Helmins worm Hookwormsattachedtotheintestinalmucosa arthropods Greekarthron joint andpod s foot whichtogethermean jointedfeet Pathogenfactors pathogenicity virulence istheabilityofapathogentoproduceaninfectiousdiseaseinanorganism Thevirulencefactorsofbacteria Methodsbywhichbacteriacausedisease Adhesion Colonization Invasion Immuneresponseinhibitors Toxins 12345 Thevirulencefactorsofbacteria Adhesion Manybacteriamustfirstbindtohostcellsurfaces Colonization Somevirulentbacteriaproducespecialproteinsthatallowthemtocolonizepartsofthehostbody Invasion Somevirulentbacteriaproduceproteinsthateitherdisrupthostcellmembranesorstimulateendocytosisintohostcells Thesevirulencefactorsallowthebacteriatoenterhostcellsandfacilitateentryintothebodyacrossepithelialtissuelayersatthebodysurface Immuneresponseinhibitors Manybacteriaproducevirulencefactorsthatinhibitthehost simmunesystemdefenses 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 Itisaspecialbacteriologicalstainusedtoid