Diphyllobothrium latum

Definitions & Key takeaways

Diphyllobothrium latum is a parasitic cestode (flatworm) contracted by ingesting raw freshwater fish, hence its reputation as the fish tapeworm. The parasite attaches to the lining of the intestine and disrupts the absorption of vitamin B12, causing its deficiency. It presents with features of vitamin B12 deficiency, including macrocytic megaloblastic anemia. Symptoms can include abdominal pain, diarrhea, weight loss, and anemia.