蛔虫、鞭虫、钩虫

Ascaris LumbricoidesP172Ascaris LumbricoidesAscaris 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 and more prevalent in the countryside than in the city 似蚓蛔线虫似蚓蛔线虫 （蛔虫（蛔虫） Ascaris lumbricoides一、形态一、形态成成虫虫活体活体2035cm1531cm蛔蛔虫虫唇唇 瓣瓣扫扫描描电电镜镜图图受受精精卵卵未未受受精精卵卵脱蛋白质脱蛋白质膜受精卵膜受精卵虫卵虫卵蛋白质膜卵壳卵细胞新月形间隙卵黄颗粒成虫成虫（小肠（小肠）卵卵 随粪入土随粪入土潮湿、荫蔽、潮湿、荫蔽、 O2充足充足21-30。 C感染期卵感染期卵经经 口口 误食、孵出幼虫、误食、孵出幼虫、 体内移行体内移行二二生生活活史史录像录像侵入侵入 肠粘膜肠粘膜 的小的小 V、小、小 L右心右心门静脉门静脉 肝肝肺肺 肺泡肺泡 （蜕皮（蜕皮 2次）次）咽咽支气管支气管气管气管 食管食管 胃胃 小肠小肠 （蜕皮（蜕皮 1次）次）蛔虫幼虫的体内移行蛔虫幼虫的体内移行：生活史的特点生活史的特点：1、 寄生部位 ：2、 感染阶段 ：3、 感染途径 ：4、 雌虫产卵 ：小肠小肠感染期卵感染期卵经口感染经口感染每天可多达每天可多达 24万个万个三、致病三、致病 （ pathogenesis)录 像录 像1、幼虫致病、幼虫致病2、成虫致病、成虫致病蛔虫性哮喘蛔虫性哮喘并发症并发症掠夺营养掠夺营养引起变态反应引起变态反应 哮喘 ,荨麻疹并发症并发症(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例直接涂片法直接涂片法四、诊断四、诊断 （ diagnosis)流行流行五、流行与防治五、流行与防治(Endemity and Prevention)改良加藤法改良加藤法防治防治Trichuris trichiura (毛首鞭形线虫 )1. Introduction:The common name ofTrichuris trichiura is whip-worm(鞭虫 ), adults live in caecum (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 spear2) Male: about 4 cm long, posterior is spirally coiled.3) Female: about 5 cm long, posterior extremity straight. 4) Egg (1) 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 eggwhen it passed with stool 3. Life cycleadults（ cecum）eggs1T7T/daily moist、 warm35winfective eggslarvae（ small intestine）adults（ cecum）migration down cecum Larvae do not enter circulation system！ingestion4. Pathologyn Feeding on tissue fluid and blood;n The slender anterior ends penetrate into the gut mucosa and make lesions;Symptoms:Symptoms are determined largely by the wormburden: n light infections are asymptomatic. n 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 children4) The infection may result in malnutrition and growth retardation 5. Diagnosisn Diagnosis is based on symptoms and the presence of eggs in feces 6. Prevalence and controln Trichuriasis often prevail with ascariasisn 17.38% of population infected with this parasite in China n The treatment and control can refer to ascariasis十二指肠钩口线虫和美洲板口线虫十二指肠钩口线虫和美洲板口线虫 （钩虫）（钩虫）(Hookworm)一、形态一、形态成成虫虫 十二指肠钩口线虫 美洲板口线虫Ancylostoma duodenale Necator americanusand消化系统的特点消化系统的特点 ：1、 口囊口囊 发发 达达2、咽管壁肌肉、咽管壁肌肉 发发 达达3、 头头 腺、咽管腺分泌腺、咽管腺分泌 抗凝抗凝素 素 、乙、乙 酰酰 胆碱胆碱 酯酯 酶酶 。大小大小体形体形口囊口囊交合伞交合伞背辐肋背辐肋十二指肠钩虫十二指肠钩虫 美洲钩虫美洲钩虫“C” “S”两两 对对 钩钩 齿齿 一一 对对 板板 齿齿交合刺交合刺尾刺尾刺 有 无圆形圆形 扁圆形扁圆形远端远端 分两支，分两支，每支再分每支再分 3小支小支基部基部 先分两支，先分两支，每支再分每支再分 2小支小支: 1013 x 0.6mm: 8 11 x 0.40.5mm: 911 x 0.4mm: 7 9 x 0.3mm十二指肠钩虫口囊十二指肠钩虫口囊 美洲钩虫口囊美洲钩虫口囊实物扫描电镜图实物扫描电镜图十二指肠钩虫口囊十二指肠钩虫口囊 美洲钩虫口囊美洲钩虫口囊实物标本实物标本十二指肠钩虫交合伞十二指肠钩虫交合伞 美洲 钩虫交合伞钩虫交合伞十十二二指指肠肠钩钩虫虫背