《蛔虫、鞭虫、钩虫》PPT课件.ppt

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 worldwide in distribution and most prevalent through out the tropics, sub-tropics

2、 and more prevalent in the countryside than in the city,似蚓蛔线虫（蛔虫）,Ascaris lumbricoides,一、形态,成虫,活体,2035cm,1531cm,蛔虫唇 瓣扫描电镜图,“品”,脱蛋白质膜受精卵,虫卵,卵,感染期卵,二 生 活 史,录像,侵入肠粘膜的小V、小L,蛔虫幼虫的体内移行：,生活史的特点：,1、寄生部位： 2、感染阶段： 3、感染途径： 4、雌虫产卵：,小肠,感染期卵,经口感染,每天可多达24万个,三、致病（pathogenesis),录像,1、幼虫致病,2、成虫致病,蛔虫性哮喘,掠夺营养,引起变态反应 哮喘,

3、荨麻疹,并发症 (国内报告 8468例),胆道蛔虫症 4556例(53.8%) 蛔虫性肠梗阻 2337例(27.6%) 蛔虫性阑尾炎 143例 蛔虫性胰腺炎 17例 蛔虫性哮喘 1352例 蛔虫性肝脓肿 33例,直接涂片法,四、诊断（diagnosis),流行,五、流行与防治 (Endemity and Prevention),改良加藤法,防治,Trichuris trichiura (毛首鞭形线虫),1. Introduction: The common name of Trichuris trichiura is whip-worm(鞭虫), adults live in caecum (

4、盲肠) of human and result in trichuriasis(鞭虫病),2. Morphology:,1) Adults resemble a whip, anterior with a hair-like lash and posterior with the handle. Mouth cavity is provided with a minute spear 2) Male: about 4 cm long, posterior is spirally coiled. 3) Female: about 5 cm long, posterior extremity st

5、raight.,4) Egg,A typical barrel shape with two polar plugs (2) Size: 50-54 m by 22-23 m (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）,eggs,1T7T/daily,moist、warm 35w,infective eggs,larvae （small intestine

6、）,adults （cecum）,migration down cecum,Larvae do not enter circulation system！,ingestion,4. Pathology Feeding on tissue fluid and blood; The slender anterior ends penetrate into the gut mucosa and make lesions;,Symptoms:,Symptoms are determined largely by the worm burden: light infections are asympto

7、matic. Heavier infections are characterized by: 1) chronic mucous and bloody diarrhea 2) abdominal pains 3) hemorrhage and anemia (贫血) or rectal prolapse (直肠脱垂) in heavy infection children 4) The infection may result in malnutrition and growth retardation,5. Diagnosis,Diagnosis is based on symptoms

8、and the presence of eggs in feces,6. Prevalence and control,Trichuriasis often prevail with ascariasis 17.38% of population infected with this parasite in China The treatment and control can refer to ascariasis,十二指肠钩口线虫和美洲板口线虫（钩虫）,(Hookworm),一、形态,成虫,十二指肠钩口线虫,美洲板口线虫,前进,Ancylostoma duodenale,Necator a

9、mericanus,and,消化系统的特点：,1、口囊发达 2、咽管壁肌肉发达 3、头腺、咽管腺分泌抗凝 素、乙酰胆碱酯酶。,大小,体形,口囊,交合伞,背辐肋,十二指肠钩虫,美洲钩虫,“C”,“S”,两对钩齿,一对板齿,交合刺,尾刺,有,无,圆形,扁圆形,远端分两支， 每支再分3小支,基部先分两支， 每支再分2小支,: 1013 x 0.6mm,: 8 11 x 0.40.5mm,: 911 x 0.4mm,: 7 9 x 0.3mm,前进,十二指肠钩虫口囊,美洲钩虫口囊,实物扫描电镜图,十二指肠钩虫口囊,美洲钩虫口囊,实物标本,十二指肠钩虫交合伞,美洲钩虫交合伞,十二指肠钩虫背辐肋,美洲钩虫

10、背辐肋,十二指肠钩虫背辐肋,美洲钩虫背辐肋,钩虫卵,中等大小,椭圆形,无色透明,48个卵细胞,极薄,卵壳与卵细胞 间有透明间隙,虫卵,二 生 活 史,迁延移行,二 、生活史,录像,侵入皮肤小V、小L,钩蚴的体内移行,录像,生活史的特点：,1、寄生部位： 2、感染期： 3、感染途径： 4、感染方式： 5、迁延移行： 6、丝状蚴特性： 7、转续宿主：,小肠,丝状蚴,皮肤、口、胎盘、乳汁等,接触泥土、生食蔬菜和转续宿主肉类、母婴传播等,向温性、向触性,猪、犬、灵猫等,录像,1、幼虫致病,2、成虫致病,三、致病（pathogenesis),1、边吸血边排血；,2、咬附部位渗血；,3、更换咬附位置，原伤

11、口仍渗血；,4、虫体活动造成组织、血管损伤引起失血。,钩虫引起贫血的原因：,四、诊断（diagnosis),直接涂片法,饱和盐水浮聚法,钩蚴培养法,五、流行与防治 (Endemity and Prevention),1.种植蔬菜与经济作物地区 2.用新鲜粪便施肥 3.种植时手脚接触泥土的机会多,钩虫病流行的特点与原因,五、流行与防治 (Endemity and Prevention),录像,1、被钩蚴污染的尿布；,2、睡沙袋、穿“土裤子”；,婴儿感染钩虫的途径：,3、经胎盘感染；,4、经乳汁感染；,钩虫病的防治,控制传染源 a).治疗钩蚴性皮炎:用左旋咪唑或15% b).治疗钩虫病:首选肠虫清

12、(阿苯达唑),联合用药,如:甲苯咪唑+噻嘧啶,噻嘧啶+左旋咪唑,粪便无害化处理 个人防护,噻苯咪唑软膏涂擦.,蛔虫的感染阶段是：,受精卵（含一个卵细胞） 感染性虫卵 未受精卵 脱蛋白质膜受精卵,思考题？,蛔虫的流行与蛔虫的：,未受精卵有关 受精卵与未受精卵都有关 受精卵无关 受精卵有关,蛔虫的主要致病阶段是：,受精卵 未受精卵 感染性虫卵 成虫,是非题？,1、钩虫幼虫在体内移行经过肺部引起哮喘是属于幼虫移行症。（）,2、蛲虫卵刚排出即对人体有感染能力（）,3、肠道寄生虫均可通过粪便查到病原体而组织寄生虫则不能。（）,思考题？,1、钩虫感染人体的主要方式及途径是：,2. 经口感染 3. 经媒介昆虫叮咬感染 4. 经胎盘感染 5. 自体感染,1. 经皮肤感染,2、俗称的“粪毒”是指：,1.昆虫性皮炎 2.尾蚴性皮炎 3.丹毒样皮炎 4.钩蚴性皮炎 5.丝虫引起的“流火”,3、钩虫排离人体阶段和感染阶段分别是