Introduction of Cestodes(Tapeworms)

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1 Introduction of Cestodes(Tapeworms)
1. 带状、体扁、分节。         长几mm至几m。如细粒棘球绦虫长2--7mm, 牛带绦虫长8m。由几个至上千个节片组成。如细粒棘球绦虫只有4节。阔节裂头绦虫由 节组成。 2.无口、无消化道、无体腔。 3. 头节有吸槽或4个吸盘 。 4. 雌雄同体。生殖器官高度发达。

2 Taenia solium Taenia saginata
链状带绦虫 Pork tapeworm / Hook tapeworm 猪肉绦虫/有钩绦虫 Taenia saginata 肥胖带绦虫 Beef tapeworm / Hookless tapeworm 牛肉绦虫/无钩绦虫

3 Taenia spp. (saginata and solium), adult worm: the chain of proglottides is called the strobila, and may be composed of over proglottides. T.saginata may measure 9 m, whereas T.solium may reach 6 m Taenia spp. adult worm The chain of proglottids is called the strobila, and may be composed of over proglottids. T.saginata may measure 9 m, whereas T.solium may reach 6 m.

4 The beef tapeworm (Living specimen)
来源 The beef tapeworm (Living specimen)

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6 Morphology Adult 乳白色、长而扁、带状、分节,雌雄同体。 3 regions of worm body：
头节scolex 、颈节neck、链体strobila

7 头节 颈部 Tape worm 链体 幼节 immature 成节 mature 孕节 ——细小、直径约1mm，具有4个吸盘。
——短而宽。生殖器官尚未发育成熟。 成节 mature 链体 ——近方形。具成熟雌雄生殖器官。 孕节 gravid proglottids ——长方形。只见子宫, 其高度分支 子宫内充满虫卵，每孕节子宫内含有几万个虫卵。

8 图：猪带绦虫 2 1 1.头节 2.头端顶面 3.成熟节片 4.孕卵节片 5.虫卵 3 5 4

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10 The scolex of T. solium hooklets rostullum suckers
The scolex of T. solium (show here) has four suckers and an armed-rostellum. The scolex of T. saginata looks similar but lacks hooks. These two species can be differentiated by counting the number of uterine branches in the proglottids; T. solium has between 7 to 13 per side, while T. saginata has 15 to 20. 来源 The scolex of T. solium

11 Gravid proglottid of T. solium
Gravid proglottid, India ink technique. Taenia solium Note : Less than 14 lateral uterine branches (one side). 来源 Gravid proglottid of T. solium

12 Can not differentiate T. saginata from T. solium
Wet mount. Note : Brown, striated embryophore. Can not differentiate T. saginata from T. solium 来源 Taenia spp. egg Can not differentiate T. saginata from T. solium

13 Egg 类圆形 卵壳薄，易破裂 壳内具有放射条纹的胚膜 embryophore 含六钩蚴 oncosphere

14 脱卵壳虫卵

15 cysticercus 囊尾蚴 白色囊状物 内含透明囊液 两层囊壁 内层增厚为头节

16 猪囊尾蚴

17 Life cycle of Taenia solium

18 Life cycle of Taenia solium The life cycle of Taenia solium is similar to that of T. saginata.  The adults (length 2 to 7 m; less than 1,000 proglottids, which are less active than in T. saginata, and each with 50,000 eggs; longevity up to 25 years) develop not only in humans but also some other animal species (monkeys, hamsters).  The cysticercus develops not only in striated muscle, but also in the brain, liver, and other tissues of pigs and other animals, including humans.  Humans develop taeniasis when they ingest undercooked pork meat containing cysticerci.  They develop cysticercosis by ingesting T. solium eggs, either by ingestion of fecally contaminated food, or by autoinfection.  In the latter case, a human infected with adult T. solium ingests eggs produced by that tapeworm, either through fecal contamination or, more arguably, from proglottids carried into the stomach by reverse peristalsis.

19 life cycle 猪（牛） 人 成虫 (人小肠) 孕节虫卵 六钩蚴 囊尾蚴 成虫 钻进肠壁 组织内 血循环 六钩蚴 囊尾蚴 钻进肠壁
带 绦 虫 卵 人吃进 血循环 六钩蚴 囊尾蚴 钻进肠壁 皮下、肌肉、脑、眼等 血循环

20 life cycle 虫卵 成虫 囊尾蚴 (人) (猪、人) 孕节 误食

21 绦虫病 Taeniasis ：口入含囊尾蚴的猪肉 囊尾蚴病 Cysticercosis ：口入虫卵
Infective stage 绦虫病 Taeniasis ：口入含囊尾蚴的猪肉 囊尾蚴病 Cysticercosis ：口入虫卵 囊尾蚴病感染方式： 自身感染：体内、体外自身感染 Intrinsic or extrinsic auto-infection 异体感染

22 Main points of life cycle
人是猪带绦虫唯一终宿主 成虫寄生于小肠内 猪带绦虫中间宿主是人或猪 猪囊尾蚴寄生于皮下肌肉和脑等组织

23 Pathogenesis 绦虫病 Taeniasis（成虫所致） 损伤肠壁，消化道功能紊乱 肠梗阻
囊尾蚴病 Cysticercosis（囊尾蚴所致） 皮下肌肉结节 脑部致癫痫,颅内高压，精神症状 眼部致视力障碍

24 致病 体壁吸收营养。微毛增大吸收面积。 (一）成虫所致绦虫病 Taeniasis 3．堵塞肠腔，引起肠梗阻 1．夺取营养
2．损伤肠壁、引起消化道症状 体壁吸收营养。微毛增大吸收面积。 饥饿感。 3．堵塞肠腔，引起肠梗阻 擦伤肠上皮细胞。 腹部隐痛、消化不 良、 恶心、腹泻、消瘦等。

25 致 病 危害比成虫大 （二）囊尾蚴所致囊尾蚴病 Cysticercosis 3．眼囊尾蚴病 1．皮下及肌肉囊尾蚴病 2．脑囊尾蚴病 最常见。
寄生皮下或粘膜。引起皮下结节或包块。 寄生肌肉, 出现酸痛感、发胀感, 假性肌肥大症。 最严重、最危险。 轻者无症状。 重者可出现三大症状：1）癫痫发作(最常见)。 2）颅内压增高 。 3）精神症状。 3．眼囊尾蚴病 危害仅次于脑囊尾蚴病。 可寄生眼任何部位。大多为单个眼。轻者视力障碍，重者失明。可致视网膜 剥离、并发白内障、青光眼等。

26 807例囊尾蚴病 眼 46％ 脑 40.9% 皮下 6.3% 肌肉 3.5% 其它 3.2%

27 Cysticercosis of the skeletal muscle
Cerebral cysticercosis

28 Subcutaneous cysticercosis

29 舌囊尾蚴病

30 猪囊尾蚴病假性肌肥大患者

31 眼结膜猪囊尾蚴病

32 Diagnosis （一）猪带绦虫病的诊断 肛拭法→查虫卵
1．询问病史 2．病原检查 1）有否吃生猪肉史 2）有否排节片史 尤其牛带绦虫 肛拭法→查虫卵 Anal swab: to find egg at perianal region 粪检法→查孕节：子宫分支鉴别虫种 Fecal exam: to find segment (species identification)

33 Diagnosis （二）囊尾蚴病的诊断 1．皮下及浅表肌肉囊尾蚴病 ——手术摘出结节、压片查头节。 2．脑及深部组织囊尾蚴病
——免疫、X线、B超、CT、核磁共振检查。 3．眼囊尾蚴病 ——眼底镜、B超，可见活动头节。

34 Epidemiology 分布：世界性，地方性 流行因素： 饮食习惯，烹调不当； 粪便污染牧草水源； 猪饲养不善－放养.

35 Treatment Taeniasis 吡喹酮首选 南瓜子槟榔疗效好 （查头节考核疗效） 阿苯达唑或吡喹酮
Cysticercosis 手术摘除 阿苯达唑或吡喹酮

36 Prevention 治疗病人 管理厕所，建圈养猪 加强肉类检验与管理 改变饮食习惯，不生食肉类

37 两种带绦虫形态比较 T. solium T. saginata Size 2-4m 4-8m
proglottids Scolex 圆顶突小钩 方无小钩 Mature proglottid Ovary 3叶 叶 Gravid proglottid: 支 支 Uterine branches

38 The scolex of T. saginata
Taenia saginata Adult-scolex 来源 The scolex of T. saginata

39 The scolex of T. saginata
Taenia saginata . Note : Four suckers, no rostellum 来源 The scolex of T. saginata Taenia saginata, fresh specimen

40 Gravid proglottid of T. saginata
Taenia saginata Gravid proglottid , India ink technique. Note : More than 14 lateral uterine branches (one side). 来源 Gravid proglottid of T. saginata

41 Cysticercus cellulosae (10*5 mm in size)

42 Life cycle of Taenia saginata
Life cycle of Taenia saginata Humans are the only definitive hosts for Taenia saginata.  The adult tapeworms (length: usually 5 m or less, but up to 25 m) reside in the small intestine, where they attach by their scolex.  They produce proglottids (each worm has 1,000 to 2,000 proglottids), which mature, become gravid, detach from the tapeworm, and migrate to the anus or are passed in the stool (approximately 6 per day).  The eggs contained in the gravid proglottids (80,000 to 100,000 eggs per proglottid) are released after the proglottid becomes free and are passed with the feces.  The eggs can survive for months to years in the environment.  Cattle and other herbivores become infected by ingesting vegetation contaminated with eggs (or proglottids).  In the animal's intestine, the eggs release the oncosphere, which evaginates, invades the intestinal wall and migrates to the striated muscles, where its develops into a cysticercus.  The cysticercus can survive for several years in the animal. Humans become infected by ingesting raw or undercooked infected meat.  In the human intestine, the cysticercus develops over 2 months into an adult tapeworm, which can survive for more than 30 years. Life cycle of Taenia saginata

43 life cycle 虫卵 成虫 囊尾蚴 （人） （牛） 误食 孕节

44 Tissue(brain, eye, skin etc.)
T.saginata T.solium D.H Human I.H Cattle Swine Habitation Small intestine Tissue(brain, eye, skin etc.) Infective stage Cysticercus bovis Cysticercus Cellulosae Egg Disease Taeniasis Cysticercosis

45 Echinococcus granulosus
细粒棘球绦虫 Echinococcus granulosus

46 Introduce 人兽共患寄生虫病 畜牧区动物群中流行 成虫寄生于犬、狼、狐等 幼虫寄生于人、牛、羊等内脏 引起棘球蚴病

47 Morphology Adult：体长4-7mm 分4节：头颈节，幼节， 成节，孕节 Egg: 与带绦虫卵相似

48 hydatid cyst 棘球蚴 圆形囊状体，似水球，直径可由不足1cm至数十厘米。 棘球蚴由囊壁和囊内含物组成。
囊壁分二层，外为角皮层，内为胚层 胚层：原头蚴 生发囊（育囊）：子囊 孙囊 原头蚴 子囊 囊内充满液体，称棘球蚴液，有强抗原性。

49 Hydatid cyst of the liver

50 hydatid sand Protoscoleces
Protoscolices with double row hooklets and calcareous corpuscles. 来源 hydatid sand Protoscoleces

51 原 头 蚴

52 生活史 成虫寄生：在狗等犬科动物小肠内。 孕节和虫卵随狗等的粪便排出体外。 人、羊等误食虫卵而导致感染。
棘球蚴多寄生于肝、肺、腹腔等，单个寄生，可存活40年 人为中间宿主

53 life cycle 虫卵 成虫 棘球蚴 (犬狼等小肠) (人羊等肝肺) 污染牧草

54 Pathogenesis 棘球蚴病或包虫病 压迫：肝、肺、脑功能障碍 过敏：囊液溢出，过敏休克 播散再生:囊内原头蚴侵入腹腔再发

55 15298例包虫病分析(新疆) 肝 69.97% 肺 19.3% 腹腔 3% 再生 5.3%

56 人脑细粒棘球蚴囊 肝包虫病 眼包虫病

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58 一个母囊内取出的子囊 掏出子囊

59 肝及腹腔多发包虫病手术 患者摘除包虫术后

60 Diagnosis 免疫诊断+超声检查 手术时取囊液查病原体 （严禁穿刺检查！） 肝包虫病人X光片

61 Epidemiology 分布：森林型、畜牧型 流行因素:犬粪污染牧草、水土 人犬密切接触 病畜内脏管理不善喂狗

62 Treatment and Control 加强个人防护，杜绝虫卵感染 处理好病畜内脏 定期为牧犬治疗 外科手术:内囊摘除术(甲醛处理)
术中应务必取尽虫囊并避免囊液外溢 造成过敏性休克或继发性腹腔感染 Albendazole长程治疗