1、Ascaris LumbricoidesP162 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 a
2、nd more prevalent in the countryside than in the city 2035cm1531cm Adult worm of A. lumbricoides蛋白质膜蛋白质膜卵壳卵壳卵细胞卵细胞新月形间隙新月形间隙卵黄颗粒卵黄颗粒n 1. Site of inhabitation: small intestine 2. Infetive stage: embryonated eggs 3. Route of infection: by mouth 4. No intermediate and reservoir hosts 5. Life span of th
3、e adult: about 1 year III. Pathogenesis There are two phases in ascariasis: 1. The blood-lung migration phase of the larvae: During the migration through the lungs, the larvae may cause a pneumonia. The symptoms of the pneumonia are low fever, cough, blood-tinged sputum, asthma. Large numbers of wor
4、ms may give rise to allergic symptoms. Eosionophilia is generally present. These clinical manifestation is also called Loefflers syndrome. n 2. The intestinal phase of the adults. The presence of a few adult worms in the lumen of the small intestine usually produces no symptoms, but may give rise to
5、 vague abdominal pains or intermittent colic, especially in children. A heavy worm burden can result in malnutrition. More serious manifestations have been observed. Wandering adults may block the appendical lumen or the common bile duct and even perforate the intestinal wall. Thus complications of
6、ascariasis, such as intestinal obstruction, appendicitis, biliary ascariasis, perforation of the intestine, cholecystitis, pancreatitis and peritonitis, etc., may occur, in which biliary ascariasis is the most common complication.哮喘哮喘,荨麻疹荨麻疹(国内报告国内报告 8468例例)胆道蛔虫症胆道蛔虫症 4556例例(53.8%)蛔虫性肠梗阻蛔虫性肠梗阻 2337例
7、例(27.6%)蛔虫性阑尾炎蛔虫性阑尾炎 143例例蛔虫性胰腺炎蛔虫性胰腺炎 17例例蛔虫性哮喘蛔虫性哮喘 1352例例蛔虫性肝脓肿蛔虫性肝脓肿 33例例 World wide distribution, very common in China, especially in the countryside.Factors favoring the spread of the transmission:1. Simple life cycle. 2. Enormous egg production ( 240,000 eggs/ day/ female ).3. These eggs are
8、highly resistant to ordinary disinfectants (due to the ascroside). The eggs may remain viable for several years. 4. Social customs and living habits.5. Disposal of feces is unsuitable.n1.Treatment to ascariasis: Mebendazole, Albendazole and Levamizole are effective.n2.Sanitary disposal of feces.n3.H
9、ygienic habits such as cleaning of hands before meals.n4.Health education.1. Introduction: The common name of Trichuris trichiura is whip-worm(鞭虫鞭虫), adults live in caecum (盲肠盲肠) of human and result in trichuriasis(鞭虫病鞭虫病) 1) Adults resemble a whip, anterior with a hair-like lash and posterior with
10、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. (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
11、 brown (4) An ovum is in the egg when it passed with stool 3. Life cycle adults（cecum） eggs1T7T/daily moist、warm 35w infective eggs larvae （small intestine） adults （cecum） migration down cecum Larvae do not enter circulation system！ingestion4. Pathology+Feeding on tissue fluid and blood;+The slender
12、 anterior ends penetrate into the gut mucosa and make lesions;Symptoms are determined largely by the wormburden: +light infections are asymptomatic. +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
13、脱垂) in heavy infection children 4) The infection may result in malnutrition and growth retardation +Diagnosis is based on symptoms and the presence of eggs in feces +Trichuriasis often prevail with ascariasis+17.38% of population infected with this parasite in China +The treatment and control can re
14、fer to ascariasis十二指肠钩口线虫美洲板口线虫“C”“S”有有无无: 1013 x 0.6mm: 8 11 x 0.40.5mm: 911 x 0.4mm: 7 9 x 0.3mm美洲美洲美洲1 1、边吸血边排血；、边吸血边排血；2 2、咬附部位渗血；、咬附部位渗血；3 3、更换咬附位置，原伤口仍渗血；、更换咬附位置，原伤口仍渗血；4 4、虫体活动造成组织、血管损伤引起失血。、虫体活动造成组织、血管损伤引起失血。 1.1.种植蔬菜与经济作物地区种植蔬菜与经济作物地区 2.2.用新鲜粪便施肥用新鲜粪便施肥 3.3.种植时手脚接触泥土的机会多种植时手脚接触泥土的机会多1 1、被钩蚴污染的尿布；、被钩蚴污染的尿布；2 2、睡沙袋、穿、睡沙袋、穿“土裤子土裤子”；3 3、经胎盘感染；、经胎盘感染；4 4、经乳汁感染；、经乳汁感染； 控制传染源控制传染源 a a) ). .治疗钩蚴性皮炎治疗钩蚴性皮炎: :用左旋咪唑或用左旋咪唑或15%15% b b) ). .治疗钩虫病治疗钩虫病: :首选肠虫清首选肠虫清( (阿苯达唑阿苯达唑) ) 联合用药联合用药,如如:甲苯咪唑甲苯咪唑+噻嘧啶噻嘧啶噻嘧啶噻嘧啶+左旋咪唑左旋咪唑 粪便无害化处理粪便无害化处理 个人防护个人防护 噻苯咪唑软膏涂擦噻苯咪唑软膏涂擦. .
