Liver Cestodes
Revision as of 14:40, 7 June 2010 by Bara (talk | contribs) (Created page with '*tapeworms *have both intermediate and final hosts in their life cycle *main expression in the UK are the encysted forms that utilise the liver a…')
- tapeworms
- have both intermediate and final hosts in their life cycle
- main expression in the UK are the encysted forms that utilise the liver and other organs in intermediate hosts
Taenia hydatigena
- the most important species
- final host
- dog
- alimentary tract
- intermediate host
- ruminant, horse, or pig
- life cycle is completed when the carnivore eats the tissues of the intermediate host containing the cysts
- the intermediate stage - Cysticercus tennuicollis
- fluid filled cysts on the surface of the liver and in the peritoneal cavity
NB: other Taenia species have muscle and brain as preferred sites in the intermediate hosts
Some can infect humans - zoonoses
Echinococcus granulosus
- Hydatid Disease
- final host
- dog, fox, and other canids
- intermediate host
- sheep most commonly affected
- ox and horses
NB: can also affect man - zoonosis
- hydatids - the cyst form
- develops from the ova
- occur in the lung and liver
- cysts are usually multiple
- 5-10cm in diameter
- contain a clear fluid with numerous scolices or "hydatid sand"
- the small calcified lesions that are sometimes present in the liver of sheep may represent degenerate hydatid cysts
- can be very prevalent in some geographical areas