2、蛔蟲、鞭蟲、鉤蟲寄生蟲

1、,Ascaris Lumbricoides,P172,,Ascaris Lumbricoides,,Ascaris lumbricoides , common saying “round worm of man”, is the largest of the intestinal nematodes parasitizing humans. It is the most common worm found in human. It is

2、 worldwide in distribution and most prevalent through out the tropics, sub-tropics and more prevalent in the countryside than in the city,似蚓蛔線蟲（蛔蟲）,Ascaris lumbricoides,♀,♂,一、形態(tài),成蟲,活體,20~35cm,15~31cm,蛔蟲唇 瓣掃描電鏡圖,“品”,脫蛋

3、白質(zhì)膜受精卵,蟲卵,,卵,感染期卵,二生活史,錄像,侵入腸粘膜的小V、小L,,蛔蟲幼蟲的體內(nèi)移行：,生活史的特點：,1、寄生部位：2、感染階段：3、感染途徑：4、雌蟲產(chǎn)卵：,小腸,感染期卵,經(jīng)口感染,每天可多達24萬個,,三、致?。╬athogenesis),錄　像,1、幼蟲致病,2、成蟲致病,蛔蟲性哮喘,,掠奪營養(yǎng),引起變態(tài)反應(yīng) 哮喘,蕁麻疹,并發(fā)癥(國內(nèi)報告 8468例),,膽道蛔蟲癥 4556例(53.

4、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),,流行,五、流行與防治　　(Endemity and Prevention),改良加藤法,防治,Trichuris trichiura (毛首鞭形線蟲),1. Introduction: The common name of Tr

5、ichuris trichiura is whip-worm(鞭蟲), adults live in caecum (盲腸) of human and result in trichuriasis(鞭蟲病),,,,,,2. Morphology:,1) Adults resemble a whip, anterior with a hair-like lash and posterior with the handle.

6、 Mouth cavity is provided with a minute spear2) Male: about 4 cm long, posterior is spirally coiled.3) Female: about 5 cm long, posterior extremity straight.,4) Egg,A typical barrel shape with two po

7、lar plugs (2) Size: 50-54 µm by 22-23 µm (3)The external layer of the shell of the egg is yellow brown (4) An ovum is in the egg when it passed with stool,,3. Life cycle,adults（cecum）,eg

8、gs,1T~7T/daily,moist、warm 3~5w,infective eggs,larvae （small intestine）,adults （cecum）,migration down cecum,Larvae do not enter circulation system！,ingestion,,,,

9、,,,,,4. PathologyFeeding on tissue fluid and blood;The slender anterior ends penetrate into the gut mucosa and make lesions;,Symptoms:,Symptoms are determined largely by the wormburden: light infections are asympto

10、matic. Heavier infections are characterized by: 1) chronic mucous and bloody diarrhea 2) abdominal pains 3) hemorrhage and anemia (貧血) or rectal prolapse (直腸脫垂) in heavy infection children 4) The

11、infection may result in malnutrition and growth retardation,5. Diagnosis,Diagnosis is based on symptoms and the presence of eggs in feces,,6. Prevalence and control,Trichuriasis often prevail with ascariasis17.3

12、8% of population infected with this parasite in China The treatment and control can refer to ascariasis,(Hookworm),一、形態(tài),成蟲,,♀,♂,♀,♂,,十二指腸鉤口線蟲,美洲板口線蟲,前進,Ancylostoma duodenale,Necator americanus,and,消化系統(tǒng)的特點：,1、口囊發(fā)

13、達2、咽管壁肌肉發(fā)達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”,兩對鉤齒,一對板齒,交合刺,尾刺,有,無,,,,,,圓形,扁圓形,遠端分兩支，每支再分3小支,基部先分兩支，每支再分2小支,,♀: 10~13 x 0.6mm,♂: 8 ~11 x 0.4~0.5mm,♀: 9~11 x 0.4mm,♂: 7 ~9 x 0.3mm,前進,十二指腸鉤蟲口囊,

14、美洲鉤蟲口囊,實物掃描電鏡圖,,十二指腸鉤蟲口囊,美洲鉤蟲口囊,實物標本,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,中等大小,橢圓形,無色透明,4~8個卵細胞,極薄,卵殼與卵細胞間有透明間隙,,蟲卵,二生活史,遷延移行,二 、生活史,錄像,侵入皮膚小V、小L,鉤蚴的體內(nèi)移行,,錄像,生活史的特點：,1、寄生部位：2、感染期：3、感染途徑：4、感染

15、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),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

16、水浮聚法,鉤蚴培養(yǎng)法,五、流行與防治　　(Endemity and Prevention),1.種植蔬菜與經(jīng)濟作物地區(qū) 2.用新鮮糞便施肥 3.種植時手腳接觸泥土的機會多,鉤蟲病流行的特點與原因,五、流行與防治　　(Endemity and Prevention),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

17、).治療鉤蚴性皮炎:用左旋咪唑或15% b).治療鉤蟲病:首選腸蟲清(阿苯達唑),聯(lián)合用藥,如:甲苯咪唑+噻嘧啶,噻嘧啶+左旋咪唑,糞便無害化處理 個人防護,噻苯咪唑軟膏涂擦.,蛔蟲的感染階段是：,受精卵（含一個卵細胞）　感染性蟲卵　未受精卵　脫蛋白質(zhì)膜受精卵,√,思考題？,蛔蟲的流行與蛔蟲的：,未受精卵有關(guān)受精卵與未受精卵都有關(guān)受精卵無關(guān)受精卵有關(guān),√,蛔蟲的主要致病階段是：,受精卵　未受精卵　感染性蟲

18、卵　成蟲,√,是非題？,1、鉤蟲幼蟲在體內(nèi)移行經(jīng)過肺部引起哮喘是屬于幼蟲移行癥。（　　）,2、蟯蟲卵剛排出即對人體有感染能力（　?。?3、腸道寄生蟲均可通過糞便查到病原體而組織寄生蟲則不能。（　?。?思考題？,1、鉤蟲感染人體的主要方式及途徑是：,2. 經(jīng)口感染3. 經(jīng)媒介昆蟲叮咬感染4. 經(jīng)胎盤感染5. 自體感染,1. 經(jīng)皮膚感染,√,2、俗稱的“糞毒”是指：,1.昆蟲性皮炎　2.尾蚴性皮炎 3.丹毒樣皮炎 4.鉤蚴

19、性皮炎 5.絲蟲引起的“流火”,√,3、鉤蟲排離人體階段和感染階段分別是：,1.蟲卵和桿狀蚴2.蟲卵和絲狀蚴3.桿狀蚴和絲狀蚴4.含蚴卵和微絲蚴5.微絲蚴和絲狀蚴,√,4、經(jīng)口吃入感染期蟲卵，可引起：,1.蛔蟲病2.鞭蟲病3.旋毛蟲病4.鉤蟲病5.蟯蟲病,√,√,√,8、關(guān)于蟯蟲，下列哪項是錯誤的：,1.生活史簡單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