Diphyllobothrium

Diphyllobothrium
Proglottids of D. latum
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Platyhelminthes
Class:	Cestoda
Order:	Diphyllobothriidea
Family:	Diphyllobothriidae
Genus:	Diphyllobothrium Cobbold, 1858
Species
Diphyllobothrium cordatum Diphyllobothrium dendriticum Diphyllobothrium elegans Diphyllobothrium lanceolatum
Synonyms
Cordicephalus Wardle, McLeod & Stewart, 1947

Diphyllobothrium is a genus of tapeworms which can cause diphyllobothriasis in humans through consumption of raw or undercooked fish. The principal species causing diphyllobothriasis is D. latum, known as the broad or fish tapeworm, or broad fish tapeworm. D. latum is a pseudophyllid cestode that infects fish and mammals. D. latum is native to Scandinavia, western Russia, and the Baltics, though it is now also present in North America, especially the Pacific Northwest. In Far East Russia, D. klebanovskii, having Pacific salmon as its second intermediate host, was identified.^[1]

Other members of the genus Diphyllobothrium include D. dendriticum (the salmon tapeworm), which has a much larger range (the whole northern hemisphere), D. pacificum, D. cordatum, D. ursi, D. lanceolatum, D. dalliae, and D. yonagoensis, all of which infect humans only infrequently. In Japan, the most common species in human infection is D. nihonkaiense, which was only identified as a separate species from D. latum in 1986.^[2] More recently, a molecular study found D. nihonkaiense and D. klebanovskii to be a single species.^[3]