Diphylloobothriasis (Fish Tapeworm Infection

Diphyllobothrium latum

Adults in the small intestine

CESTODES (TAPEWORMS)

• 1. Most infections are asymptomatic but gastrointestinal symptoms may occur in some patients.
• 2. Aberrant migration of proglottids can cause cholecystitis or cholangitis. Rarely, massive infections may cause intestinal obstruction.

• 1. Eggs are passed unembryonated in feces then ingestion by a suitable crustacean.
• 2. Crustacean then is eaten by fish.
• 3. Freshwater and marine fishes, commonly perch and pike for Dibothriocephaluslatus.

In addition to humans, other carnivorous, fish-eating mammals and a few birds can also serve as definitive hosts.

Consumption of undercooked paratenic host fish.

• 1. Microscopic identification of eggs in the stool is the basis of family level diagnosis.
• 2. Identification of proglottids passed in the stool is also of diagnostic value.