人體寄生蟲學(xué)課件：Cestoda（絳蟲）

1、Cestoda（絳蟲）Teaching Building: No. 5 Office Room: 5303-1Taenia soliumTaenia solium(鏈狀帶絳蟲) is called pork tapeworm(豬肉絳蟲、豬帶絳蟲、有鉤絳蟲).Adult worms live in human small intestine causing taeniasis (絳蟲病). The larval stage cysticercus(bladder worm) lives in pigs tissues and occasionally in human tissues causi

2、ng cysticercosis（囊尾蚴病或囊蟲?。? Above diseases are prevalent all over the world.The global distribution of teniasis/cysticercosis infection WHO estimates that 50 million people are infected by the teniasis/cysticercosis complex, and that 50,000 of them die each year (0.1 %). I. Morphology1. Adult is fla

3、ttened and ribbon-like, creamy white in color.I. Morphology1. Adult measures about 2-4 m. It has 700-1000 proglottides.1. Adult is composed of a head, neck and segmented strobilus(鏈體).Strobilus: consist of proglottides(節(jié)片) including young, mature & gravid proglottides.scolexneckstrobilusYoung proglo

4、ttid未成熟節(jié)片Mature proglottid成熟節(jié)片Gravid proglottid妊娠節(jié)片I. Morphology(1) Scolex Global, 1mm 4 suckers1 rostellum(頂突 )25-50 hooklets arranged in a double crown Image and text copyright Dennis Kunkel. (2) Neck The short and slender neck is the budding zone containing germinative cells from which new segmen

5、ts grow to form a long strobilus. (3) StrobilaImmature proglottid 未成熟節(jié)片（幼節(jié))Mature proglottid 成熟節(jié)片（成節(jié)） Gravid proglottid 妊娠節(jié)片（孕節(jié)）Immature (young) proglottides are transverse rectangle, located in the anterior part of the body and inner organs are developing. Mature proglottidSquare in shape , located

6、 in the mid part of the body and have developed reproductive organsIncluding 150-200 testesA centrally straight uterus 3 lobes of ovary A vitelline glandGravid (pregnant) proglottidLong rectangle, located in the posterior part of the body and contain a branched uterus filled with 40000 eggsThe numbe

7、r of main branches on each side of the uterus stem is 7-13India Ink TechniqueThe species confirmation can be made by counting the number of the main lateral branches of uterusNote : less than 13 lateral uterine branches (one side)2. EggSphericalAverage 34m in diameter With a thick radially striated

8、brown embryophore (胚膜)Inside each is an oncosphere (六鉤蚴) with 6 hookletsThe eggs of Taenia saginata and T. solium are indistinguishable morphologically3.Cysticercus (bladder worm)A semitransparent and elliptic bladder, white, 0.6-1cmFilled with fluid and a white invaginated scolex with 4 suckers and

9、 hooklets in the bladderBean-pork meat (米豬肉或豆豬肉)The scolex evaginates Under stimulation of bile The scolex invaginatesin the bladderII. Life cycle1.Definitive (Final) host: man2.Intermediate host: pig (or man) 3.Infective stage: cysticercus and egg4.Infective mode: eating raw bean-pork5. Site of inh

10、abitation: adult in small intestine, cysticercus in tissues6. Infective mode of cysticercosis: endo-auto-infection, exo-auto-infection and foreign infection7.Life span: more than 25 years; the cysticercus can survive 5-6 years in human bodyLife Cycle of Taenia solium Attach to intestinal mucosascole

11、x evaginates adults gravid proglottides develop into fall off duodenum In human small intestine and are 2-3 months discharged in feces man eats cysticercus in raw pork Pig eats eggs or In intermediate hosts man gets infection 60-70days develop into cysticercus onchosphere hatch in all parts of the b

12、ody larval migration in duodenum penetrate intestinal wall into blood streamIII. Pathogenesis and Clinical Manifestations1. Teaniasis The adult irritates the small intestine and produces toxic materials causing abdominal pain, indigestion, diarrhea, emaciation, nervous disorder, urticaria, eosinophi

13、lia and etc.2. Cysticercosis The clinical manifestations vary with the location and number of cysticerci. Cysticercosis is divided into three types.(1) Subcutaneous and muscular typeThe subcutaneous nodules are usually found in torso, arms, legs, neck, and face. They are movable and painless. The mu

14、scular pain results from worms in muscles. Note this cysticercus in the tongue(2) Ocular typeThe cysticercus in the eye causes visual disturbance.A died worm will provokes the local inflammation leading to blindness.(3) Brain typeClinical manifestations include headache, nausea, vomiting, epilepsy (

15、癲癇), paralysis (癱瘓), diplopia (復(fù)視), disequilibrium (平衡障礙), dizziness (頭暈), mental disorder and weakness in limbs. NeurocysticercosisThree main symptoms: epilepsy, intracranial pressure (顱內(nèi)壓增高), mental disorder.Image courtesy of Dr. Ana Flisser, National Autonomous University of Mexico IV. Diagnosis1

16、.The confirmative diagnosis of taeniasis is made by finding the characteristic gravid proglottids or eggs. (1) Direct fecal smear; (2) floatation technique; (3) scotch tape technique （壓片）for gravid proglottid 2. Cysticercosis: Biopsy for subcutaneous type; Ophthalmoscope for ocular type; X-ray, Comp

17、uterized tomograph (CT) and magnetic resonance (MR) for brain3. Immunological tests are for reference only: Enzyme-linked immunosorbent assay (ELISA) MR ImageV. Treatment and prevention1. Treatment of taeniasis (1). Chinese herb medicine: Areca nut (檳榔) and Pumpkin seed（南瓜子）are very effective and sa

18、fe. (2). Praziquatel can be used for the patient in whose brain there is no cysticercus. It is very effective.2. Treatmen of cysticercosisSurgical removal is required for ocular and superficial cysticercosis. Praziquantel is effective for the cerebral cysitcercosis but the patient must take praziqua

19、ntel in a special hospital. 3. Prevention(1) Health education; pay attention to personal and food hygiene; (2) Avoid eating raw or uncooked pork; (3) Sanitary inspection of slaughter house; (4) Control and sanitary disposal of feces; (5) Treat all patients to eradicate the source of infection. A clo

20、se mouth catches no fliesTaenia saginataTaenia saginata is called beef tapeworm （牛肉絳蟲、牛帶絳蟲、無鉤絳蟲、肥胖帶絳蟲）.The adult worm lives in the human small intestine and cause taeniasis. The larval stage (cysticercus bovis) lives in the cattle tissues. This disease is prevalent all over the world. 1. Body length

21、 & number of proglottid 24m, 7001000 proglottidsI. MorphologyDifferences between T. solium and T.saginata 48m, 10002000 proglottids2. scolex T. solium T. saganita1mm in diameter, with 4 suckers and hooklets 2mm in diameter , with 4 suckers but no hooklet 3. Mature proglottid T. solium T. saginata3 l

22、obes of ovary 2 lobes of ovary 4. Gravid proglottid T. soliumT. saginata713 uterine leteral branches on one side 1530 uterine leteral branches on one side 5. CysticercusCysticercus cellulose Cysticercus bovisscolex with hooklets found in pig and man no hooklet on scolex only found in cattle The biol

23、ogical differences between T. solium and T. saginata_ T. solium T. saginata_Number of gravid usually several segments usually single segmentproglottid detached Mode of proglottids passively expelled actively migrate out of anuspassing outDisease caused in man taeniasis and cysticercosis taeniasis_ E

24、gg: same as that of T. solium II. Life cycleIII. PathogenesisUsually only single worm is present and the patient is no symptom. Some patients may complain of migrating proglottids from anus with pruritus at the perianal region. Abdominal discomfort, nausea, vomiting, constipation or diarrhea may occ

25、ur. IV. DiagnosisFinding of gravid proglottids by scotch tape technique. Finding of eggs at the perianal region by cellophane tape method.V. Treatment Same as that of T. solium南瓜子200g去皮、炒熟、研末，清晨空腹口服1小時(shí)后口服檳榔片（150-200g）煎劑200ml半小時(shí)后再口服2030g硫酸鎂導(dǎo)瀉 Notice:The successful criterion of therapy is that the sco

26、lex is expelled, so the recognition of the scolex in the patients stool after the application of taenifuge is important. When the entire worm has been expelled, the therapy is successful, otherwise the strobila will regrow if the scolex remains in the small intestine.Echinococcus granulosus細(xì)粒棘球絳蟲包生絳

27、蟲或犬絳蟲The adult worm lives in the small intestines of canine animals.Its metacestode (larval stage) lives in the tissues of herbivores or man, which causes echinococcosis (hydatid disease or hydatidosis棘球蚴病或包蟲病). This disease is prevalent in pastoral areas. 1. AdultThe smallest tapeworm, 2-7mm.It con

28、sists of a scolex, neck and three segments.I. Morphology 1. AdultScolex is about 0.3 mm in diameter, bears a rostellum with a double crown of 28-48 hooklets and 4 suckers. The middle proglottid has 45-65 testes, and paired irregular ovaries. The gravid proglottid has a median uterus with from 12 to

29、15 lateral branches filled with about 500 ova. 2. EggSame as T. solium and T. saginata3. Hydatid cyst（棘球蚴）Hydatid cyst is spherical, from 1cm to 20 cm in size in the human or animal body.3. Hydatid cyst （棘球蚴）II. Life cycle 1. Definitive hosts: dogs (canine)2. Intermediate hosts: herbivores (sheep, goat, camel, horse) and man3. Infective stage: egg4. Infective route: ingesting eggs by mouth5. Hydatid cyst survives 40 years, several generations are in a cy