人体寄生虫学 Clonorchis sinensis(肝吸虫)

IntroductionToTrematodesClonorchisSinensisCommonFeaturesofHumanTrematodes1.Mostadulttrematodesaredorsoventrallyflattened,bilaterallysymmetric,leaf-shapedortongue-like.2.Allofthemhavetwosuckers,anoralandaventralsucker.3.Thedigestivetractisdegenerate.Theendofintestineisacecumwithoutanus.4.Thereproductivesystemisdevelopedandhermaphroditic.5.Excretorysystemincludesflamecells,capillaries,collectingtubulesandanexcretorybladder.6.Eggsofmostspecieshaveanoperculum(lid,盖)and/orasmallspine(knob).Thedevelopedeggcontainsamiracidium.7.Theyarebiohelminths.Onlygettingintofreshwatercaneggsdevelop.Theirintermediatehostsareinwater.1stintermediatehostsareallsnailsand2ndintermediatehostsvariesfromspecies.8Alternationofgenerationsispresentintheirlifecycles.9.Infetivestageisusuallyametacercria10.Lifecyclemodel:adult成虫eggs虫卵miracidium毛蚴sporocyst胞蚴redia雷蚴cercaria尾蚴encystedmetacercaria囊蚴water

SexualreproductionasexualreproductionDIGENELARVAEeggmiracidiumsporocystcercariarediaClonorchissinensisClonorchissinensiswasnamedafterthatthewormwasdiscoveredinthebileductofaChinesecarpenterinCalcutta,aharborcityofIndia,in1874.ourarchaeologistsfoundthisworminabodyfromatombdatingfromthesecondcenturyB.C.inJiangling,HubeiProvince.TheChineseliverflukeisdistributedinAsia(FarEastregion).Theinfectionsresultfromeatingraworhalf-cookedfreshwaterfishandshrimps.Thewormsblockingthebilepassagescauseclonorchiasis,whichfinallymaybecomethebiliarycirrhosis.I.morphology1.Adult:

(1)sunflowerseed-like;(2)measuring10-25x3-5mm;(3)theoralsuckeratthetopisslightlylargerthantheventralsuckerlocatedintheanterior1/5partofthebody;(4)reproductivesystemishermaphroditic;genitalporeisinfrontoftheacetabulum;twodeeplybranchedtestesintandemarelocatedintheposteriorthirdpartofthebody;theovary,oviduct,uterusareinthemidpart;vitellineglandsareinthelateralfields;(5)thedigestivetractisdividedintotwoceca;(6)thepouch-likedexcretorybladderopensattheposteriorend.AdultwormofC.sinensis2.Egg:lookslikeasesameseedunderthelowpowerandawatermelonseedunderthehighpower.Itisyellowbrownincolor,averages29x17чm(thesmallesthelminthegg).Theshellisthickandthereareanoperculumandasmallknobontheposteriorend.Thecontentisamiracidium.3.metacercariaisspherical,0.138X0.1mm,infishmuscles.Clonorchissinensisegg.ScanningelectronTheoperculumisvisibleononeend.Thesurfaceoftheeggiscoveredwithawrinkledmembrane,givingitanappearanceofmelonskin.Ⅱ.LifeCycle1.Infectivestage:metacercaria;2.Infectiverouteandmode:eatingrawfreshwaterfishandshrimpswithmetacercariae;3.Siteofinhabitation:bileducts;4.Biohelnimth:1stInt.hosts:Bithyniasnail;2ndint.hosts:fishofFamilyCyprinidaesuchaspseudorasboraparva麦穗鱼,Cypriuscarpio鲤鱼,Aristichthysnobilis大头鱼,Mylopharyngodonpiceus青鱼.5.Reservoirhosts:Cat,dog;6.Lifespan:20-30years,1stInt.hosts:BithyniafishofFamilyCyprinidaesuchaspseudorasboraparva麦穗鱼Cypriuscarpro鲤鱼Aristichthysnobilis大头鱼Mylopharyngodonpiceus青鱼hissinensisShandongUniversissinensisMetacercariaeareingestedwithraworundercookedinfectedfishLarvamigratestobileductWormmaturesinbileductLarvahatchesin1smallintestineEggspass\infeces'EggseatenbysnailCyprinoidfishCercarialeaves/snail,Iencystsonfish/MiracidiumhatchesinsnailAdultsliveinbileductMetacercariainfishmuscle)hissinensisⅢ.pathologyandsymptomsLiverflukesliveinbilepassages（mechanicalandchemicalirritations）InflammationandproliferationofbiliaryepitheliumFibrosisofthepassagewallandmechanicalobstructionduetowormsBilestreamblockageHighpressureinbileductsEnlargementofbileductBilesecretionstopsbacterialinfectionCholangitis（胆管炎）Cholecystitis（胆囊炎）cholelithiasis（胆石症）BileisstoredincreasinglyinhepaticCellsanddiffusesbetweenthemPortalv.hypertensionfunctionfailureAscites,splenomegaly，anemia，comalivercancerDegenerationoflocalhepaticcellsNecrosisoflocalhepatieccellsRegenerationofdamagedtissueBiliarycirrhosjs（thelivergetshardandgreen）die肝吸虫感染肝脏标本Clinicalmanifestation(1)Lightinfection:nosymptoms(2)Generalcase:poorappetite,fullnessinabdomen,diarrhea,physicalweakness,hepaticpain,hepatomegaly.(3)Severecase:icterus(jaundice),systemictoxemia,chill,fever,vomiting,vertigo,mentaldisorder,emaciation,ascites.Thepatientsdieofcoma,infectivecomplications,hemorrhageofupperpartofdigestivetract.(4)Inchildcase:physicalandmentalgrowthsareretarded(dwarf).肝肿大腹水类侏儒症型肝吸虫病IV.

DiagnosisSymptoms+signs+experienceofeatingrawfishandshrimp+discoveryofliverflukeeggStoolexamination:*1.alkalidigestivemethod(NaOH10%)2.Watersedimentationmethod3.Directfecalsmear*4.Duodenalaspiration(drainage)5.lmmunologictestsareforreferenceonly.V.

TreatmentandPrevention1.Drugofchoiceispraziqantel(吡喹酮).Othereffectivedrugsincludehexachloroparaxylol(六氯对二甲苯)，bithionol(硫双二氯酚或别丁bitin).2.Prevention(1)Healtheducation