Diphyllobothrium

Diphyllobothrium is a genus of parasitic tapeworms of the class Cestoda inhabiting the gastrointestinal tracts of fish, birds, humans and other animals. Humans become infected by eating raw or undercooked freshwater fish carrying the larvae of Diphyllobothrium latum, the broad fish tapeworm, which can grow to many metres and cause vitamin B12 deficiency. Prevention relies on thorough cooking or freezing of fish, proper sewage treatment and inspection of freshwater fisheries. Sushi and sashimi suppliers mitigate the risk through verified freezing protocols that kill the larvae.