宿主防御區(qū)段-人體寄生蟲血吸蟲交通醫(yī)學(xué)部

Bloodflukes 2015.4Schistosomesareagroupofcloselyrelatedflukesthatinhabitintheportalvascularsystemofmanymammalian.Thereare6specieswhichcaninfectSchistosomahaematobium（埃及血吸蟲）,Schistosomamansoni（曼氏血吸蟲）,Schistosomajaponicum（ SchistosomaSchistosomajaponicum–isdistributedinFarEastandSchistosomajaponicumliveinthemesentericvenules（腸系膜靜脈）ofhumanbodyandotheranimals.Theeggsdepositinwallofintestineandliverandresultinseveredamagetointestineandliver----Morphology–TheyaredioeciousThemalesareshorterthantheTheventralsuckerisneartheoralsucker.Thepairedintestinesconvergeandfuseataboutthemidpointofworm,andthencontinueasasingleguttotheposteriorGut(fuseasingleMale1.2cmlong.Thebodyisflattenedbehindtheventralsucker,andincurvedventrallytoformalongitudinalgroove,gynecophoral (thefemaleresidesinSeventestesarebehindventral77cFemale1.6cmlong,TheovaryisneartheTheuterusisMorphology--Nearlycircularoval,lightyellowishbrownandwithoutanoperculum.Theymeasure67μmby89μm A ateralspineatoneendofThematureeggincludedamiracidium（毛蚴liberateanumberof LifeLifeLifeLifeDevelopmentinintermediathost(snail)Eggs----theciliatedmiracidiaMiracidia----mothersporocysts----daughtersporocysts(noredia)----manycercariae(snail).Cercariaeemergefromthesnailandreachwater.生活LIFE在外界發(fā)蟲 毛 胞蚴（母、子 尾（糞）（水 （釘螺 （水釘Developmentinhumancercariaeswim,penetratetheskinofthehuman,andshed(castoff)theirforkedTheschistosomulaemigratethroughtissuestotheirresidenceintheveins.AdultsresideinthemesentericvenulesThefemalesdepositeggsinthesmallvenules(intestinalwallorliver).Theeggsaremovedtowardthelumenoftheintestine,andareeliminatedwithfeces. 內(nèi)發(fā)尾 童 成（水 （皮下靜脈 （腸系膜靜脈蟲（肝、腸壁CharacteristicsoflifeHumanisfinalhost(indirectlife-Thelocationofadult:mesentericvenules.Infectivestage:Theintermediatehost:Reservoirhost:cattle,dogs,cats,pigs,andotheranimals.Eggsdepositinthewallofgutand 主要致病階段是童蟲血管炎/栓塞/破裂/侵潤 成蟲有時引起腎損害（III型超敏反應(yīng)）蟲卵沉淀于肝及結(jié)腸壁等組織引起蟲卵Schistosomecercarialdermatitis（尾蚴性皮炎Cercarialdermatitisfollowsskinpenetrationbycercariae.CercarialmechanicaldamagetotheImmediatehypersensitivityreactionsoccurattheinvasionsites.Petechialhemorrhages（點狀 edema（水腫）,pruritus（瘙癢）,maculopapularrash（丘疹）.蟲卵致病機(jī)卵內(nèi)毛 可溶性卵抗原（SEA)，刺T淋巴細(xì)胞，使其致敏。當(dāng)致敏的T細(xì)胞再次受到抗原（SEA）刺激后，T種淋巴因子并吸引淋巴細(xì)胞、巨噬細(xì)胞、酸性粒細(xì)胞及纖維細(xì)胞等到蟲卵周圍而形成蟲卵肉芽腫(IV型超敏反應(yīng))。Clinicschistomiasis---Withtheproductionofeggs,theeggsretainedintheintestineandlivertissueinduceinflammation.TheeggsliberateanumberofSEA,evokingminuteabscesses.Theseabscessesfacilitatetheirpassageintothelumen.Theformationofgranuloma（肉芽腫）,fibrosis（纖維化）oftissue(intestinalwallandliver).病理變---病變部位主要是肝臟和結(jié)腸肝臟（門靜脈分支末端）維纖維化、干線型肝硬化結(jié)腸壁（橫結(jié)腸、乙狀結(jié)腸和直腸壁）蟲卵肉芽腫---嗜酸性膿腫---潰瘍---瘢疤---腸壁增厚---腸腔狹窄。ClinicalAcuteChronic----Intestinal----Hepatosplenic----Otherbodysiteand（后遺癥臨床分型及表急性血吸蟲病：發(fā)燒、腹痛、腹瀉、粘液血便、肝腫大、干咳、哮喘等。慢性血吸蟲?。郝愿雇?腹瀉/痢疾(間歇)、肝脾腫大、結(jié)腸壁增厚等。多無明顯癥狀。晚期血吸蟲?。焊斡不?、腹水、門脈高壓、脾臟明顯腫大，甚至消化道 、肝 。侏儒癥(兒童異位血吸蟲?。寒愇患纳彤愇粨p害（肺和腦）AcuteAcuteschistosomiasis(Katayamafever)isassociatedwithheavyprimaryinfectionsandtheinitiationofeggproduction.Characteristicsymptomsincludehighfever,hepatosplenomegaly（肝脾腫大）eosinophilia（酸性粒細(xì)胞升高）anddysentery（痢疾Thisclinicalsyndromeoccursafewweeksaftertheprimaryinfection.IntestinalAseggsaredepositedinthetissues,theantigenicsubstancereleasedbyeggsinvokeahostimmuneresponse.Theformationofgranulomaaroundtheeggs.Granulomaaggregationintheintestinetractwallisthemajorcauseofpathologicchange.TissueofManyeggsareretainedinintestinalLymphocytes,eosinophils,macrophages,andfibroblastsinfiltratearoundeggs.Theintestinalwall esinflamed,thickened,andfibrotic,evenleadingtomechanicalobstruction.LateLatehypersensitivityHepatosplenicEggsdepositedintheportaltriadsoftheliverstimulateagranulomatous（肉芽腫的）response,leadingtocontinuousfibrosisoftheperiportal Themajoreffectoftheliverchangesistheblockageofportalbloodflow,resultinginincreasedportalhypertension（門脈高壓）andthedevelopmentofcollateralcirculation(esophagealvarices).Theliverincreasesinsize.Theliverewhiteandhard.Ascites（腹水）maybeThespleen escongested（充血）andincreasesgreatlyinsize.

血吸 的免 -皮膚和肺血吸蟲的免疫逃封閉抗體假說（卵抗原—童蟲抗原抗 假說（宿主成分包被抗原模擬假說（同源 序列表面受體假說（童蟲有IgGFc受體表膜改變（表膜迅速脫落LaboratoryMicroscopicidentificationofeggscollectedinstoolisthemethodofchoice.TheeggsarebestseeninthedirectsmearortheconcentrationThelarvae(miracidium)maybecultivatedbyfecalcultureinatesttube–毛蚴培養(yǎng)法.Tissuebiopsy(rectalbiopsy，結(jié)腸活檢)maydemonstrateeggswhenstoolexaminationsarenegative.Immunologicaltest:Intradermal（皮試）CercariaeHullenReaction(CHR，尾蚴膜實驗),Circumovalprecipitintest(COP，環(huán)卵沉淀實驗),IHA,ELISA.TreatmentandThedrugofchoiceis（吡喹酮）forinfectionsSanitarydisposalofAvoiddirectcontactwithwatercontaminatedbycercariae.Control