Hydatid disease is caused by the larval forms of Echinococcus tapeworms. E. granulosus is the most frequent parasite, whereas E. multilocularis causes a more aggressive clinical disease.
Hydatid disease is caused by hydatid cysts:
- Echinococcus granulosus :
- classic form of hydatid cyst
- affects liver, lung, kidneys, spleen, brain, musculoskeletal system, heart
- Echinococcus multilocularis :
- alveolar (multilocular) hydatidosis
Structural components of the hydatid cyst :
outer acellular laminated membrane
germinal membrane
protoscolices, attached and budding from the membrane
Localization
pulmonary echinococcosis (pulmonary hydatid cyst)
hepatic echinococcosis (hepatic hydatid cyst)
cardiac echinococcosis (cardiac hydatid cyst)