1. Diphyllobothrium Latum
Karla Bennett
May 2012

2. General Information It is known as the “fish tapeworm”
Diphyllobothrium latum is a cestode (a hermaphrodiditic worm that is a parasite of the vertebrate intestinal tract).

3. Terminology
Plerocercoid-the larval form. Also the infective stage found in the raw flesh of freshwater fishes.
D. latum- the adult worm
Proglottids- the segments of the flat worm. Each contains both male and female reproductive organs
Scolex- the part on the anterior end that is long and spoon-shaped. It is what the worm uses to attach itself to the intestinal tract.

4. History of Diphyllobothriasis
Its distribution is worldwide
It occurs where pickled or insufficiently cooked fish are part of the cultural diet. (Northern temperate areas)

5. Hosts and Intermediates
Intermediates: Freshwater fish and copepods
Definitive host: Humans and other vertebrates.

6. Life Cycle

7. Symptoms constipation diarrhea fatigue obstruction of the bowel
pernicious anemia (caused by vitamin B12 deficiency) which can lead to subacute combined degeneration of spinal cord
stomach pain
vomiting
weight loss.

8. Diagnosis and Treatment
Examination of a fecal sample for eggs and proglottoids is the quickest way to diagnose Diphyllobothriasis.
All diphyllobothrium species respond to the same treatment.
The best method is a diatrizoic acid injection into the duodenal wall.
Praziquantel or niclosamide are not as effective because they do not remove the attached head from the intestine wall.

9. Prevention
Cook fish properly. If you eat sashimi or sushi, freeze it first at -10 °C (or below) for two days to kill the tapeworm larvae.
Do not defecate in water. If the fish tapeworm larvae cannot get in touch with the intermediate hosts, they cannot infect humans.

10. Citation
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11. TRIVIA! Name 3 symptoms of Diphyllobothriasis.
What is the name of the best drug for treatment and why is it better than the others?
Name the two intermediate hosts in the lifecycle.
What is the name of the anatomical body part of the parasite that it uses to attach itself to the intestine?
Why does the entire adult worm need to be removed?