第一篇医学蠕虫(MedicalHelminth)一、医学蠕虫定义(DefinitionofHelminth)借肌肉的伸缩而蠕动,故名蠕虫,与医学有关的蠕虫,被称为医学蠕虫。总论(Generality)◆土源性蠕虫:这类蠕虫在发育过程中不需要中间宿主,虫卵从终宿主排至外界,在土壤中发育为感染阶段,直接经口或皮肤感染新宿主。Soil-bornnematode:requirednointermediatehost总论(Generality)二、分类(Classification)◆生物源性蠕虫:在发育过程中必须有中间宿主,方能完成其生活史。其幼虫必须经过在中间宿主体内的发育,才能感染新宿主。Bio-bornnematode:requiredintermediatehost总论(Generality)二、分类(Classification)•Nematoda线虫•Cestoda绦虫•Trematoda吸虫医学蠕虫(MedicalHelminth)总论(Generality)形状体腔消化系统生殖系统发育阶段中间宿主危害性线虫成虫>幼虫线状/圆柱状原体腔有口有肛门雌雄异体卵-幼虫-成虫有/无形态生活史线虫纲概述(GeneralityforNematoda)◆土源性线虫:线虫纲概述(GeneralityforNematoda)◆生物源性线虫旋毛形线虫(Trichinellasapiralis)丝虫(Filaria)线虫纲概述(GeneralityforNematoda)似蚓蛔线虫(蛔虫)AscarislumbricoidesClinicCase•A2yearsoldfemalechilddevelopedfever,chills,asthmaticattack(哮喘)andseveredyspnea(呼吸困难).Shedied5dayslater,duringthemedicalcareurgency.Thediagnosiswaspneumonia,associatedwithLoeffier'ssyndrome.Loeffier‘ssyndrome:cough,asthma(哮喘),lowfever,biood-tingedsputumorhemoptysis(咯血),chest-pain,inflammationshadowsinlungsunderX-ray.Thesemanifestationsgoonabout2weeks.Figure1:thealveolarlumenofthelung(肺泡腔)withlongitudinalsections(纵切面)oftheA.lumbricoideslarvae,associatedwithpneumonia.(H&Ex200)ClinicCaseFigure2:thetransversalsections(横切面)oftheA.lumbricoideslarvae.Notetheintestine(central),pairedexcretorycolumnsandtwoproeminentlateralalae(侧线)(diagnosticaspects).Thecuticle(表皮)istransverselystriated.Thereisanintenseinfiltrationbyeosinophilicleukocytes(嗜酸性粒细胞)atthealveolarwall.(H&Ex400)ClinicCase似蚓蛔线虫(蛔虫)Ascarislumbricoides是种大型线虫,寄生于人体的小肠中引起蛔虫病,此病呈世界性分布,但发达国家的感染率明显较低,如美国为1%,而我国农村为90%AscarismorphologyadultShapeColorStructureofhead(×40)唇瓣lip乳突papillaeAscarismorphologyadultStuctureoftail(×40)交合刺AscarismorphologyadultStructureofalimentarytract口ora食道gullet肠intestines直肠recta肛门anusAscarismorphologyadultFemalegenitalsystem子宫uterus输卵管oviduct卵巢overy生殖孔genitaloraAscarismorphologyadulttransversalsections角皮层cutinlayer皮下层endermiclayer侧线lateralalae纵肌层transversalmusclelayer消化道alimentarytractAscarismorphologyadult受精蛔虫卵Fertilizedegg(×100)半月型间隙Crescent-shapedspacing蛋白膜albuminouscoat卵壳shell卵细胞oocyst形状颜色大小内容物卵壳Ascarismorphologyegg受精蛔虫卵Fertilizedegg形状颜色大小内容物卵壳受精膜壳质层蛔甙层Ascarismorphologyegg脱蛋白质膜的受精蛔虫卵(×100)Fertilizedeggwithoutalbuminouscoat卵细胞oocystAscarismorphologyegg卵壳shell半月型间隙Crescent-shapedspacing未受精蛔虫卵unfertilizedegg(×100)卵壳shell卵黄细胞yelkcell蛋白膜albuminouscoatAscarismorphologyegg感染性蛔虫卵(×100)embryonatedeggs幼虫larvalwormsAscarismorphologyeggAscarislifecycle人体内人体外经口感染性虫卵食物、水胃小肠幼虫•小肠血心肺气管食道小肠成虫虫卵受精蛔虫卵感染性虫卵22-30℃有氧、阴蔽潮湿的土壤中约三周随粪便排出Ascarislifecycleconclusion◆第一次蜕皮在虫卵内◆第二、三次蜕皮在肺泡内◆第四次蜕皮在小肠内,发育为童虫蜕皮ecdysisAscarislifecycleconclusion•蛔蚴移行症:蛔...