Manual of basic techniques for a health laboratory - libdoc.who.int

4. Parasitology 151Fig. 4.101 SchistosomesFig. 4.102 Hydatid cystsLength: 0.5–1.5cm.Colour: white.The flat male is rolled around the thread-like female, which is slightly longer. Eachschistosome has two suckers near the head.Echinococcus granulosus (hydatid cyst)Echinococcus granulosus worms are found in dogs. The worms are 3–6mm long.Humans and livestock may become infected by accidental ingestion of the eggs,which then develop into hydatid cysts in the liver or lungs (Fig. 4.102).Size: about 150mm.Shape: round, irregular or oval, with one pole slightly flattened.Content: fine granules and a distinct ring of 10–30 hooklets.Colour: colourless and transparent.Hydatid disease occurs preferentially in areas where sheep are bred, such as Eastand North Africa, South America, the Arabian peninsula, Australia and NewZealand.