蛔蟲、鞭蟲、鉤蟲(北大)課件

復(fù)習(xí)題？1.試述保蟲宿主與轉(zhuǎn)續(xù)宿主的區(qū)別。2.寄生蟲為什么能在有免疫力的人體中生存而不被排除？寄生蟲病的傳播途徑包括污染或含有寄生蟲的感染期的土壤水食物節(jié)肢動(dòng)物傳播媒介√√√√寄生蟲感染階段是指寄生蟲的：感染人體階段感染保蟲宿主階段感染中間宿主階段感染中間宿主階段感染昆蟲媒介階段√人體寄生蟲病的傳染源包括：僅有病人和帶蟲者醫(yī)學(xué)節(jié)肢動(dòng)物

所有野生動(dòng)物

病人、帶蟲者、感染的動(dòng)物√關(guān)于蟯蟲，下列哪項(xiàng)是錯(cuò)誤的：1.生活史簡(jiǎn)單2.感染率兒童高于成人，城市高于農(nóng)村3.生活史屬間接型4.帶蟲者和病人是唯一的傳染源5.感染方式主要是人群中的間接接觸和肛門－手－口直接感染√AscarisLumbricoidesP162AscarisLumbricoides

Ascarislumbricoides,common

saying“roundwormofman”,isthelargestoftheintestinalnematodesparasitizinghumans.Itisthemostcommonwormfoundinhuman.Itisworldwideindistributionandmostprevalentthroughoutthetropics,sub-tropicsandmoreprevalentinthecountrysidethaninthecity

似蚓蛔線蟲（蛔蟲）Ascarislumbricoides♀♂一、形態(tài)成蟲活體20~35cm15~31cm活體AdultwormofA.lumbricoides蛔蟲唇瓣掃描電鏡圖“品”受精卵未受精卵脫蛋白質(zhì)膜受精卵

蟲卵蛋白質(zhì)膜卵殼卵細(xì)胞新月形間隙卵黃顆粒成蟲（小腸）卵隨糞入土潮濕、蔭蔽、O2充足21-30。C感染期卵經(jīng)口誤食、孵出幼蟲、體內(nèi)移行二生活史錄像錄像侵入腸粘膜的小V、小L右心門靜脈肝肺肺泡（蛻皮2次）咽支氣管氣管食管胃小腸（蛻皮1次）蛔蟲幼蟲的體內(nèi)移行：

1.

Siteofinhabitation:smallintestine2.Infetivestage:embryonatedeggs3.Routeofinfection:bymouth4.Nointermediateandreservoirhosts

5.Lifespanoftheadult:about1year

生活史的特點(diǎn)：III.Pathogenesis

Therearetwophasesinascariasis:1.Theblood-lungmigrationphaseofthelarvae:Duringthemigrationthroughthelungs,thelarvaemaycauseapneumonia.Thesymptomsofthepneumoniaarelowfever,cough,blood-tingedsputum,asthma.Largenumbersofwormsmaygiverisetoallergicsymptoms.Eosionophiliaisgenerallypresent.TheseclinicalmanifestationisalsocalledLoeffler’ssyndrome.2.Theintestinalphaseoftheadults.Thepresenceofafewadultwormsinthelumenofthesmallintestineusuallyproducesnosymptoms,butmaygiverisetovagueabdominalpainsorintermittentcolic,especiallyinchildren.Aheavywormburdencanresultinmalnutrition.Moreseriousmanifestationshavebeenobserved.Wanderingadultsmayblocktheappendicallumenorthecommonbileductandevenperforatetheintestinalwall.Thuscomplicationsofascariasis,suchasintestinalobstruction,appendicitis,biliaryascariasis,perforationoftheintestine,cholecystitis,pancreatitisandperitonitis,etc.,mayoccur,inwhichbiliaryascariasisisthemostcommoncomplication.錄像致?。╬athogenesis)錄像1、幼蟲致病2、成蟲致病蛔蟲性哮喘并發(fā)癥掠奪營(yíng)養(yǎng)

引起變態(tài)反應(yīng)哮喘,蕁麻疹并發(fā)癥(國(guó)內(nèi)報(bào)告8468例)膽道蛔蟲癥4556例(53.8%)蛔蟲性腸梗阻2337例(27.6%)蛔蟲性闌尾炎143例蛔蟲性胰腺炎17例蛔蟲性哮喘1352例蛔蟲性肝膿腫33例直接涂片法四、診斷（diagnosis)改良加藤法錄像五、流行與防治

(EndemityandPrevention)Worldwidedistribution,verycommoninChina,especiallyinthecountryside.Factorsfavoringthespreadofthetransmission:1.

Simplelifecycle.2.Enormouseggproduction(240,000eggs/day/female).3.Theseeggsarehighlyresistanttoordinarydisinfectants(duetotheascroside).

Theeggsmayremainviableforseveralyears.4.Socialcustomsandlivinghabits.5.Disposaloffecesisunsuitable.流行1.Treatmenttoascariasis:Mebendazole,AlbendazoleandLevamizoleareeffective.2.Sanitarydisposaloffeces.3.Hygienichabitssuchascleaningofhandsbeforemeals.4.Healtheducation.防治Trichuristrichiura(毛首鞭形線蟲)1.Introduction:

Thecommonnameof

Trichuristrichiuraiswhip-worm(鞭蟲),adultsliveincaecum(盲腸)ofhumanandresultintrichuriasis(鞭蟲病)

2.Morphology:

1)Adultsresembleawhip,anteriorwithahair-likelashandposteriorwiththehandle.Mouthcavityisprovidedwithaminutespear2)Male:about4cmlong,posteriorisspirallycoiled.3)Female:about5cmlong,posteriorextremitystraight.

4)

EggAtypicalbarrelshapewithtwopolarplugs(2)Size:50-54μmby22-23μm

(3)Theexternallayeroftheshelloftheeggisyellowbrown(4)Anovumisintheeggwhenitpassedwithstool3.Lifecycleadults（cecum）

eggs1T~7T/dailymoist、warm3~5w

infectiveeggslarvae

（smallintestine）

adults

（cecum）

migrationdowncecumLarvaedonotentercirculationsystem！ingestion

4.PathologyFeedingontissuefluidandblood;Theslenderanteriorendspenetrateintothegutmucosaandmakelesions;Symptoms:Symptomsaredeterminedlargelybythewormburden:lightinfectionsareasymptomatic.Heavierinfectionsarecharacterizedby:1)chronicmucousandbloodydiarrhea2)abdominalpains3)hemorrhageandanemia(貧血)orrectalprolapse(直腸脫垂)inheavyinfectionchildren4)Theinfectionmayresultinmalnutritionandgrowthretardation5.DiagnosisDiagnosisisbasedonsymptomsandthepresenceofeggsinfeces6.PrevalenceandcontrolTrichuriasisoftenprevailwithascariasis17.38%ofpopulationinfectedwiththisparasiteinChinaThetreatmentandcontrolcanrefertoascariasis

十二指腸鉤口線蟲和美洲板口線蟲（鉤蟲）(Hookworm)一、形態(tài)成蟲♀♂♀♂十二指腸鉤口線蟲美洲板口線蟲前進(jìn)AncylostomaduodenaleNecatoramericanusand消化系統(tǒng)的特點(diǎn)：1、口囊發(fā)達(dá)2、咽管壁肌肉發(fā)達(dá)3、頭腺、咽管腺分泌抗凝素、乙酰膽堿酯酶。大小體形口囊交合傘背輻肋十二指腸鉤蟲美洲鉤蟲“C”“S”兩對(duì)鉤齒一對(duì)板齒交合刺尾刺有無圓形扁圓形遠(yuǎn)端分兩支，每支再分3小支基部先分兩支，每支再分2小支♀:10~13x0.6mm♂:8~11x0.4~0.5mm♀:9~11x0.4mm♂:7~9x0.3mm前進(jìn)十二指腸鉤蟲口囊美洲鉤蟲口囊實(shí)物掃描電鏡圖十二指腸鉤蟲口囊美洲鉤蟲口囊實(shí)物標(biāo)本十二指腸鉤蟲交合傘美洲鉤蟲交合傘十二指腸鉤蟲背輻肋美洲鉤蟲背輻肋十二指腸鉤蟲背輻肋美洲鉤蟲背輻肋鉤蟲卵大小形狀顏色卵殼內(nèi)容物其他中等大小橢圓形無色透明4~8個(gè)卵細(xì)胞極薄卵殼與卵細(xì)胞間有透明間隙卵細(xì)胞透明間隙卵殼蟲卵二生活史成蟲（小腸）卵隨糞入土潮濕、蔭蔽、O2充足25~30。C桿狀蚴經(jīng)皮膚、體內(nèi)移行、2次蛻皮、5~7周2次蛻皮絲狀蚴（感染期幼蟲）遷延移行二、生活史錄像侵入皮膚小V、小L右心肺肺泡咽支氣管氣管食管胃小腸（蛻皮2次）鉤蚴的體內(nèi)移行錄像生活史的特點(diǎn)：1、寄生部位：2、感染期：3、感染途徑：4、感染方式：5、遷延移行：6、絲狀蚴特性：7、轉(zhuǎn)續(xù)宿主：小腸絲狀蚴皮膚、口、胎盤、乳汁等接觸泥土、生食蔬菜和轉(zhuǎn)續(xù)宿主肉類、母嬰傳播等向溫性、向觸性豬、犬、靈貓等錄像1、幼蟲致病2、成蟲致病三、致病（pathogenesis)鉤蚴性皮炎“糞毒”鉤蚴性肺炎哮喘腹瀉和異嗜癥貧血消化道出血嗜酸性粒細(xì)胞增多癥嬰兒鉤蟲病1、邊吸血邊排血；2、咬附部位滲血；3、更換咬附位置，原傷口仍滲血；4、蟲體活動(dòng)造成組織、血管損傷引起失血。鉤蟲引起貧血的原因：四、診斷（diagnosis)直接涂片法飽和鹽水浮聚法鉤蚴培養(yǎng)法優(yōu)點(diǎn)缺點(diǎn)簡(jiǎn)便易行易漏診檢出率高，可鑒定蟲種費(fèi)時(shí)檢出率高，較常用稍費(fèi)時(shí)五、流行與防治

(EndemityandPrevention)

1.種植蔬菜與經(jīng)濟(jì)作物地區(qū)

2.用新鮮糞便施肥

3.種植時(shí)手腳接觸泥土的機(jī)會(huì)多鉤蟲病流行的特點(diǎn)與原因五、流行與防治

(EndemityandPrevention)錄像1、被鉤蚴污染的尿布；2、睡沙袋、穿“土褲子”；嬰兒感染鉤蟲的途徑：3、經(jīng)胎盤感染；4、經(jīng)乳汁感染；鉤蟲病的防治

控制傳染源

a).治療鉤蚴性皮炎:用左旋咪唑或15%

b)