1 / 25

Echinococcus granulosus ( 细粒棘球绦虫 )

Echinococcus granulosus ( 细粒棘球绦虫 ). GENERAL INTRODUCTION Worldwide distribution Extra-intestinal tapeworm Small tapeworm Laval infection of E. granulosus may cause serious clinical disease ---hydatidosis/ hydatid disease. Morphology. Only 2-8 mm long Usually comprises of-

kbusby
Download Presentation

Echinococcus granulosus ( 细粒棘球绦虫 )

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Echinococcusgranulosus(细粒棘球绦虫)

  2. GENERAL INTRODUCTION • Worldwide distribution • Extra-intestinal tapeworm • Small tapeworm • Laval infection of E. granulosus maycause serious clinical disease ---hydatidosis/ hydatid disease

  3. Morphology • Only 2-8 mm long • Usually comprises of- • Scolex: with four suckers and 2 circular rows of hooks • neck • immature proglottid • mature proglottid • gravid proglottid • The eggs of E.granulosus and Teania spp. are indistinguishable

  4. Hydatid Cyst: • Round & cystic • Wall – cuticle layer, germinal layer • Contents • cystic fluid, brood capsules, protoscolex, daughter & grand daughter cysts (hydatid sands)

  5. Hydatid cyst Cuticle layer Germinal layer Daughter cyst Granddaugher cyst Protoscolex Brood capsule Brood capsule

  6. Hydatid cyst

  7. Daughter cysts

  8. protoscolex

  9. Life cycle

  10. Definitive host: dog & other canine • Intermediate host: sheep, cattle, camel & human • Infective stage: egg (gravid proglottid) • Sites of hydatid:liver, lungs, abdominal cavity, spleen, kidneys, heart, bones, central nervous system etc • Man is a dead end host

  11. Adult worms in intestine of dog

  12. Pathogenesis • Cause Hydatid Disease (Hydatidosis) • Sites of hydatid cyst: liver, lungs, abdominal cavity, spleen, kidney, heart, bones, brain etc Analysis of 15,289 cases in Xinjiang,China • Liver 69.97% • Lung 19.3% • Abdominal cavity 3%

  13. Clinical menifestations • Depends on the size, the location and the number of cyst. • Pressure –by tremendous size of the cyst. results in disfunction of liver, lung or nervous system • Allergy -due to rupture of cyst, may cause severe allergic reaction • Regeneration – due to rupture of cyst, intracystic protoscolex or germinal layer may be transplanted and result in multiplesecondary infection Secondary regeneration 5.3% • Toxicosisby secretion of worm

  14. Surgical removal of the cysts

  15. Diagnosis • History of contacting with sheep & dogs • Clinical symptoms of a slow-growing tumor accompanied by eosinophilia are suggestive • Parasitological examination for finding scolexes, brood capsules & daughter cysts • Cysts in organs or calcified cysts can be visualized using x-rays, CT & B-ultrasound examination • Biopsy are forbidden unless during operation

  16. Serological examination for specific Ab or Cag. • Intradermal (Casoni) test with hydatid fluid is useful. • Antibodies against hydatid fluid antigens have been detected in a sizable population of infected individuals by ELISA or indirect hemagglutination test.

  17. CT, brain B-ultrasound, liver X-ray, lung CT, liver

  18. Man's arm showing positive skin test for hydatid disease

  19. Epidemiology World distribution. South America (Argentina, Brazil, Uruguay etc ),North America (American, Canada etc) Europe(Iceland, Russia, France, Spain etc), Africa (Kenya, Libya, Egypt, Tunisiaetc ).

  20. Endemic Factors • Contamination of the feces by infected dogs • Intimate contact between dog, herbivorous animal and man in local district • Traveling to endemic areas & importing from endemic areas

  21. Control and treatment • Regular treatment of infected dogs to reduce worm load. • Prevention of dogs from eating infected offals of domestic animals(sheep,etc) in the endemic areas. • Health education and strict personal hygiene. • Avoidance of unnecessary contact with infected dogs. • Surgery is still remains the mainstay of the treatment of hydatid disease. • Albendazole have proved to be effective against hydatid cyst(for median or small size cysts).

  22. Summary T. solium T. saginata E. granulosus Proglottides700-1000 1000-2000 only 3 Rostellumpresent absent present Hooks 25-50 absent 24-48 Uterine branches 7-13 15-30 unregularly branched Definitive hosthuman human dog/wolf Intermediate hostpig/human cattle sheep/human Infective stageegg/cysticercus cysticercus egg

More Related