2. dlmedu ryx Trematodes Department of Parasitology Dalian Medical University Ren Yixin

3. dlmedu ryx 8 lessons 6 lessons Trematodes 2 lessons Cestodes a review Clonorchis sinensis Paragonimus westermani Fasciolopsis buski Schistosoma japonicum Teania solium Teania saginata

4. dlmedu ryx TrematodeCestode suckers ribbonlike

5. dlmedu ryx common names Clonorchis sinensis: Chinese liver fluke Paragonimus westermani: lung fluke Fasciolopsis buski: intestine fluke Schistosoma japonicum: blood fluke Teania solium: pork tapeworm Teania saginata: beef tapeworm

6. dlmedu ryx Common characters of Trematodes MorphousLife cycle

7. dlmedu ryx Introduction to Trematoda digenetic trematodes Leaf-shaped or elongate flat body, resistant cuticle, bilaterally symmetrical without body cavity 2 suckers oral sucker ventral sucker Monoecism male and female reproductive system are in the same body attachment locomotion

8. Morphology of Adult Schistosoma

9. dlmedu ryx Trematode Digestive Tract Simple mouth pharynx esophagus intestine Anus absent

10. dlmedu ryx Male reproductive system two testis vas efferens 输出管 vas deferens 输精管 Seminal vesicle 储精囊 prostatic gland 前列腺 ejaculatory duct 射精管 cirrus 阴茎 cirrus pouch 阴茎袋

11. dlmedu ryx Female reproductive system Ovary 卵巢 Oviduct 输卵管 Ootype 卵模 Mehlis gland 梅氏腺 Seminal receptacle 受精囊 Laurer ’ s canal 劳氏管 Vitellaria 卵黄腺 Vitelline duct 卵黄管 Vitelline reservior 卵黄囊 （ vitelline glands ） Uterus 子宫

12. dlmedu ryx Eggs liver fluke's egg lung fluke's egg intestine fluke's eggblood fluke's egg

13. dlmedu ryx Life cycle: several development stages of a fluke Adult eggs miracidium sporocyst Adolescaria metacercaria cercaria redia 童虫 囊蚴 毛蚴胞蚴 雷蚴

14. dlmedu ryx cercariasporocyst metacercaria

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16. One or two intermediate hosts are required : First intermediate host is snail second intermediate host is fresh water fish (clonorchis sinensis) second intermediate host is crab, crayfish (Paragonimus)

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18. *Characters of life cycle* The trematodes are biohelminths, they need 1 or 2 intermediate hosts, the first intermediate host is mainly fresh water snail. Asexual reproduction occurs in the larval stages, sexual reproduction occurs in the adult stage.

19. dlmedu ryx Clonorchis sinensis 华支睾吸虫 Chinese liver fluke Disease is Clonorchiasis In China: more than 1.2×10 7

20. dlmedu ryx The Chinese liver fluke, the trematode Clonorchis sinensis discovered in the bile passage of a Chinese at autopsy in Calcutta, India in 1875 firstly

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22. Morphology Life cycle Pathogenesis & clinical manifestation Diagnosis Epidemiology Prevention & treatment

23. dlmedu ryx Morphology of Clonorchis sinensis Adult : elongate, narrow, 10-25 mm long,3-5mm wide.

24. dlmedu ryx oral sucker pharynx ceca Acetabulum ventral sucker genital pore Seminal receptacle uterus ovary Testis esophagus

25. dlmedu ryx Morphology of Clonorchis sinensis Egg: the smallest 29 ×17µm operculum Tiny knob eggshell broad rim ("shoulder") miracidium

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27. Life cycle of C.sinensis eggmiracidiumsporocystredia cercariametacercarialarva rediacercariametacercaria adult

28. dlmedu ryx Life cycles parafossarulus

29. dlmedu ryx redia

30. dlmedu ryx cercaria

31. dlmedu ryx metacercariae

32. dlmedu ryx First intermediate hosts

33. dlmedu ryx Second intermediate host

34. dlmedu ryx The patholgical consequences of C.sinensis occur mainly in intra-liver secondary bile ducts. The ultimate effect depends on the intensity and duration of the infection. burdens usually small (20-200) Pathogenesis

35. dlmedu ryx Pathogenesis Worm in bile ducts Mechanical irritation Toxic substances Erosion of epithelium Proliferation in biliary epithelium Bile retention, fibrosis,cancer Left lobe is mostly involved

36. dlmedu ryx Two adult worms (arrow) in the ductal lumen

37. dlmedu ryx Pathogenesis extreme thickening of the bile duct (epithelium proliferate). fibrosis * Cholangitis

38. dlmedu ryx White areas show cirrhosis in infected liver * Cirrhosis of liver

39. dlmedu ryx Other symptoms: Jaundice upper abdominal distress diarrhea hepatomegaly

40. dlmedu ryx Epidemiology source of infection route of transmission susceptible population

41. dlmedu ryx Source of C.sinensis infection: Infected human Infected livestock Infected wild animals

42. dlmedu ryx Epidemiology Fish ponds where both snails and fish are present.

43. dlmedu ryx Epidemiology raw fish is considered a delicacy

44. dlmedu ryx Epidemiology Human is infected by eating raw, undercooked, frozen, dried, salted, smoked fish. Metacercariae in fish can withstand salting, smoking, frozen and drying. second intermediate hosts

45. dlmedu ryx Epidemiology Definitive host: Human Reservoir hosts: dogs, cats and rats First and second intermediate host Way of acquiring: eating raw fish with metacercariae

46. dlmedu ryx Diagnosis small with operculum at constricted end broad rim tiny knob 卵 盖 Detection of the characteristic eggs in stool or in bile or fluid obtained from duodenum Associate the history of eating raw fish

47. dlmedu ryx Prevention: safe consumption of infective fish proper sanitation control of human feces. control of the snail and the reservoir hosts The drug of choice is praziquantel 吡喹酮 75 mg/kg, divided 3 doses one day, 2-3days Treatment of Clonorchis sinensis