Tiny Worms – Big Trouble II: Echinococcus granulosus

What kind of pathogen is the dog tapeworm?

Echinococcus granulosus is a tapeworm (Cestoda) measuring 4–7 mm in length, with a hook-bearing scolex and (usually) three proglottids. The mature terminal segments contain up to 1,500 eggs, which are excreted with the dog’s faeces. After the eggs are ingested by the intermediate host, the larvae hatch in the gut and travel in the bloodstream. They primarily attach to the liver, and less commonly to the lungs or other organs, where hydatid cysts form. These consist of a host capsule, a laminated membrane and a germinal layer, from which brood capsules containing protoscolices develop.

Where is the dog tapeworm found?

Echinococcus granulosus is found worldwide. In Europe, the parasite is mainly found in Mediterranean countries and the Balkans,…