D.latum Ova (courtesy of the CDC)
Diphyllobothriasis in humans is caused by a parasite called Diphyllobothrium latum. This parasite belongs to the phylum Platyhelminthes and the class Cestodes. Cestodes are more commonly known as tapeworms due to their flat, ribbon-like body. Diphyllobothrium is the genus to which numerous species belong. Latum is the name of the species that primarily infects humans. Although, several other Diphyllobothrium species have been reported to infect humans, but less frequently; they include D. pacificum, D. cordatum, D. ursi, D. dendriticum, D. lanceolatum, D. dalliae, and D. yonagoensis. D. latum is believed to be the largest human tapeworm, often growing to lengths between 1 and 2 meters (3-7 feet) and potentially capable of attaining 10 meters (32 feet). Other synonyms for this parasitic disease are Dibothriocephalus anemia, fish tapeworm infection, and broad fish tapeworm infection.
Chances are that if you have ever eaten any Sushi, ceviche or uncooked fish you have been at risk for being infected by D.latum! (although not at sufficiently high risks...) So read on!