Echinococcus multilocularis (1)

Question 1

What is the common name?

Answer 1

Alveolar Hydatid tapeworm

Question 2

What are the final hosts?

Answer 2

Dogs

Cats

Wild canids

 - Red fox
 - Coyote
 - Arctic fox and wolf

Question 3

What are the intermediate hosts?

Answer 3

Rodents

Lagomorphs

Livestock

Humans

Question 4

Describe adults

Answer 4

Up to 6 mm long

Question 5

Describe the 2nd stage larvae

Answer 5

Alveolar Hydatid cyst

Liver with metastasis to other organs

Question 6

Describe eggs

Answer 6

25-40 micro m

Round

Thick shelled

Question 7

Explain the life cycle

Answer 7

Larval stage is alveolar Hydatid cyst

 - Not confined by a capsule
 - Exogenous budding

Infiltrates surrounding tissue

Diffuse growth composed of many compartments (each filled with a gelatinous matrix and many brood capsules)

Hydatid grows like a malignant neoplasm
- Center dies and is filled with necrotic tissue

Grows large becoming space occupying lesion
- Causes pressure necrosis of surrounding tissue

Invasive growth in humans can be fatal

Question 8

What is the site of infection in adults?

Answer 8

Small intestine

Question 9

What is the site of infection of larvae?

Answer 9

Alveolar hydatids in liver

Question 10

Describe the Pathogenesis

Answer 10

Found only in the Northern Hemisphere

Exogenous growth common

Question 11

What is important about Echinococcus multilocularis?

Answer 11

It is ZOONOTIC