ORGANISM 8--Echinococcus granulosus
COMMON NAME: Hydatid cyst tapeworm.
GEOGRAPHICAL DISTRIBUTION: Worldwide
PATHOGENESIS: Varies with location of cysts, inflammation reactions, fibrous cysts,
pressure necrosis of adjacent tissue, hepatic cysts often in right
lobe; cysts also in lung, kidneys, bones, brain, and other organs;
secondary infections; eosinophilia.
HABITAT: Intestine of canines (adult worm); soft tissue and bones of intermediate host
INTERMEDIATE HOST: Man and herbivores, sheep.
RESERVOIR HOST: Carnivores (dogs).
INFECTIVE FORM: Egg for intermediate hosts; protoscolices for dogs or other canines.
MODE OF INFECTION: Ingestion.
SPECIMEN SOURCE: Dog feces or tissue (surgical).
Figure 3-52. Life cycle of Echinococcus granulosus.