Diphyllobothrium latum is the
Human tapeworm that comes from fish. Fish and copepod's (crustaceans
found almost everywhere where water is available and they constitute
the biggest source of protein in the oceans) are the intermediate
hosts, while humans and bears are the definitive hosts. The fish,
often pike or salmon, (second host) usually come from arctic and
sub-arctic waters. Many encounters occur when the fish migrate from
salt water to fresh water for breeding. Humans become infested with
the Diphyllobothrium latum tapeworm by ingesting raw or undercooked
The disease resulting from the infestation is called, Diphyllobothriasis.
The symptoms are abdominal distention, flatulence, intermittent
abdominal cramping, and diarrhea. An infestation of Diphyllobothrium
latum may also cause an onset of anemia. The tapeworm competes for
vitamin B12 and it is also thought to interfere with the absorption
of the vitamin, leaving the host susceptible to both Pernicious
anaemia and Megablastic anaemia.
The increased popularity of sushi increases the incidence of Diphyllobothrium
latum infestations in the United States.