Taxonomic position Phylum platyhelminthes Class Cestoda GENERAL INTRODUCTIONS MORPHOLOGICAL FEATURES Flat and Segmented Scolex equipped with organs of attachment ID: 1045081
Download Presentation The PPT/PDF document "Cestode (tapeworm) " is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
1. Cestode (tapeworm)
2. Taxonomic position Phylum platyhelminthes Class Cestoda GENERAL INTRODUCTIONS
3. MORPHOLOGICAL FEATURESFlat and SegmentedScolex-equipped with organs of attachment: suckers, hooks, groovesNeck - germinal portion germinal – development Strobila:Proglottids – Immature proglottidMature proglottidgravid proglottid
4. Proglottids – each segment in the strobila of a tapeworm, containing a complete sexually mature reproductive system.Gravid – carrying eggs
5. Body wall: Tegument and subtegument (syncytial layer); no coelomic cavityMonoeciousMORPHOLOGICAL FEATURES
6. A coelom is a cavity lined by an epithelium derived from mesoderm. Organs formed inside a coelom can freely move, grow, and develop independently of the body wall while fluid cushions and protects them from shocks
7.
8. Monoecious - (of a plant or invertebrate animal) having both the male and female reproductive organs in the same individual; hermaphrodite.
9. syn·cy·tium - a single cell or cytoplasmic mass containing several nuclei, formed by fusion of cells or by division of nuclei.
10. PHYSIOLOGY AND PATHOGENESIS Surface absorption capabilities Highly developed reproductive functions Anaerobic metabolism All species are parasitic Pathogenic stage may be adult or the larva
11. Metacestode stageLarval stage of a cestode that develop in the intermediate host. Cysticercus - Taenia spp. Hydatid cyst - Echinococcus granulosus Alveolar hydatid cyst - E. multilocularis Cysticercoid - Hymenolepis spp.
12. Taenia soliumTeania saginataEchinococcus granulosusSpirometra mansoniHymenolepis nanaHymenolepis diminutaImportant species
13. Taenia soliumTaenia saginata
14. GENERAL INTRODUCTION Worldwide distribution Large tapeworm Larval infection of Taenia solium may cause serious clinical disease ---CYSTICERCOSIS Taenia solium
15. MorphologyCan be up to 2 to 4 meters long It has a globular scolex with four suckers and 2 circular rows of hooks (rostellum)The gravid proglottids are 5×10 mm with a 7-13 branched uterusThe eggs of T. solium and T. saginata are indistinguishable
16. scolex of T. solium.
17.
18. eggs of Taenia solium and T. saginataThe eggs are rounded or subspherical, diameter 31 - 43 µm, with a thick brown embryophore. Inside each egg is an embryonated oncosphere with 6 hooks. A complete egg always has the primary membrane (shell) that surrounds eggs.
19.
20. Cysticercus
21. Cyticercus - a larval tapeworm that is at a stage in which the scolex is inverted in a sac, and that is typically found encysted in the muscle tissue of the host.
22. Life cycle of T.solium
23. Main points of the life cycle Man is the only definitive host, but he can also be the intermediate host for T.solium Pig is the important intermediate host for T.solium Adult worm reside in the lumen of the upper part of small intestine The infective stage to man are both egg/gravid proglottid and cysticercus for T.solium
24. A tapeworm larval cyst (cysticercus) is ingested with poorly cooked rice-like meatThe larva escapes the cyst and passes to the small intestine where it attaches to the mucosa by the scolex suckersThe proglottids develop as the worm matures in 3 to 4 months
25. Main points of the life cycleThe adult may live in the small intestine as long as 25 years and pass gravid proglottids with the feces When eggs consumed by pigs in which they hatch and form cysticerciT.solium eggs can also infect humans and cause cysticercosis (larval cysts in lung, liver, eye, maxillofacial region and brain)
26.
27. Pathogenesis and clinical featuresAdult worm —TaeniasisLight infections remain asymptomaticHeavier infections may produce abdominal discomfort, epigastric pain, vomiting and diarrhea
28.
29. Metacestode stage –CysticercosisThe cysticercus stage of T. solium can be found anywhere in the body -- subcutaneous, muscles, eye, brain Regardless of the tissue affected, pathological consequences are those of a space-occupying lesion Cysticerci in brain tend to grow a larger size than those in other tissues The process of calcification may be accompanied by the release of antigens -- inflammatory reaction
30. CysticercosisThe incidence of cerebral cysticercosis can be as high 1 per 1000 population and may account for up to 20% of neurological case in some countries (e.g., Mexico); cysticercosis ocular involvement occurs in about 2.5% of patients and muscular involvement is as high as 10% (India).
31. subcutaneous nodulesCysticercus on the eyegroundpseudohypertrophy of muscle
32. Cysticerci in brain
33. Cysticerci in heart
34. Cysticerci in tongue
35. DIAGNOSIS For adult worm infection (Teaniasis) ＊ History of eating raw pork ＊ Find gravid proglottids in feces＊ Perianal swab to find eggs
36. For cysticercosis ＊ Specific diagnosis is difficult to establish, the history and adult worm infection attribute to strong suspicion ＊ Biopsy to subcutaneous lesions ＊ Computerized axial tomography or magnetic resonance imaging＊ Serological examination for specific antibody
37. Epidemiological distributionHigh prevenlence Medium prevelenceLow or no prevelenceEpidemic limited areaData unavialableWorld-wide distribution.Epidemic in central and south America (Mexico), Africa, South-east Asia, eastern Europe, Micronesia .
38. PRINCIPLES OF CONTROL Treat all patients to eradicate the source of larvae parasitism Pumpkin seed and areca nut ; Praziquantel Avoid the fecal contamination of pig feedModernization of raising pigs Pay attention to personal and food hygiene Intensive examination of the pork Adequate cooking or freezing of meat are effective precautions cysticerci do not survive at temperatures below -10℃ and above 50 ℃.
39. Teania saginataCan be up to 4 to 8 meters long The scolex with four suckers The gravid proglottids with a 15-30 branched uterusThe eggs of T. solium and T. saginata are indistinguishable
40.
41. gravid proglottid of T. soliumgravid proglottid of T. saginata
42. LIFE CYCLE
43. Human is the only definitive host, cattle is the intermediate host Adult worm reside in the lumen of the upper part small intestine The infective stage to man is larvaNo cysticercus in humanLIFE CYCLE
44. PATHOGENESIS The adult parasite induces some host reaction The process of calcification may be accompanied by the release of antigens -- inflammatory reaction
45. DIAGNOSIS For adult worm infection Find gravid proglottids in feces
46. T.saginata is prevalent in regions where cattle are raised: Africa, Middle-East, Central and South America, Europe and Asia.DISTRIBUTION
47. PRINCIPLES OF CONTROL Treat the patients --Pumpkin seed and areca nut; PraziquantelModernization of raising cattle Intensive examination of the beef
48. COMPARISON OF THE TWO TAPEWORMS T. soliumT. saginataSizeScolexMature ProglottidGravid proglottid Intermediate HostDisease caused Infective stage Diagnosis Clinical significanceChemotherapy2-4mRostellum & hooks3 lobes of ovaryUterine Branches<13Swine & HumanTaeniasis & cysticercosisEgg & CysticercusEgg may be found in stoolMuch more importantShould be instant4-8mNo2 lobes of ovary >15CattleTaeniasis only Cysticercus Only Perianal egg exam Less than T. soliumNot so urgent