Below you will find more information about Bothriocephalosis from Medigest. If you believe that you are suffering from any of the symptoms of Bothriocephalosis it is important that you obtain an accurate diagnosis from a medical professional to ensure that you obtain the correct medication or treatment for your condition. There are medical conditions that carry similar symptoms associated with Bothriocephalosis and therefore the information provided by Medigest is offered as a guideline only and should never be used in preference to seeking professional medical advice. The information relating to Bothriocephalosis comes from a third party source and Medigest will not be held liable for any inaccuracies relating to the information shown.


Bothriocephalosis (also known as Diphyllobothriasis) is an infection with an intestinal parasite. The parasite is a fish tapeworm known as Diphyllobothrium latum. Human infection is caused by eating undercooked fish contaminated with the bacteria. Adult tapeworms may infect humans, felines, canids, pinnipeds, bears, and mustelids, though the accuracy of the records for some of the nonhuman species is disputed. Immature eggs are passed in the feces of the mammal host (the definitive host, where the worms reproduce).


Microscopic identification of eggs found in the stool is the basis of specific diagnosis. Eggs are typically numerous and can be demonstrated without concentration techniques. Examination of proglottids passed in the stool can also be of diagnostic value. Diagnostic tools include microscopy and morphologic comparison with other intestinal parasites. Though it is hard to identify the eggs or proglottids to the species level, the difference among them is of little medical importance because, like most adult tapeworms in the intestine, all members of this genus respond to the same drugs.


Praziquantel and niclosamide are historical treatments that should no longer be used as first line of therapy in developed countries because they result in destruction and disintegration of the worm which may make it impossible to confirm that the scolex (or head of the worm) has been passed, which is the only way to confirm cure. Praziquantel or niclosamide should only be given out in situations when endoscopy is not available or is not possible. The preferred treatment for all tapeworm infections is injection of diatrizoic acid into the duodenum, which causes the worm to detach itself and be passed whole.

Symptoms and Signs

Bothriocephalosis can last for decades if left untreated. Most infections are do not show symptoms. Manifestations may include diarrhea, abdominal discomfort, vomiting and weight loss. Vitamin B12 deficiency with subsequent megaloblastic anemia can occur, but has not for several decades in infections caused by D. latum, possibly because of improved nutrition. In one test, almost half of the ingested vitamin was absorbed by D. latum in otherwise healthy patients, while 80-100% was absorbed by the worm in patients with anemia. It is not known why anemia happens in some cases but not others. Massive infections may also result in intestinal obstruction. Migration of proglottids can lead to cholecystitis or cholangitis. Patients affected by bothriocephalosis may also suffer from abdominal pain, nausea, and a reduced appetite. Anemia and Vitamin B12 deficeincy can also result from the infection. Females cases are disproportionately reported, most likely because of the higher likelihood for them to be involved in meal preparation, rather than any morphological differences.

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