ORGANISM 9--Echinococcus multilocularis
COMMON NAME: Hydatid cyst tapeworm.
GEOGRAPHICAL DISTRIBUTION: Northern Hemisphere, in cold or arctic climates.
PATHOGENESIS: Varies with location of cyst; inflammatory reactions; fibrous cysts;
hemorrhages; cyst pressure; necrosis of adjacent tissues; hepatic
cysts often inthe right lobe; cysts also in lung, kidneys, bones, brain and other
organs; may metastasize like a cancer; secondary infections; eosinophilia;
HABITAT: Intestine of canines (adult worm); soft tissue and bones of intermediate
hosts (larval stage).
INTERMEDIATE HOST: Man and mice, moles and herbivores.
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 3-54. Life cycle of Echinococcus multilocularis.