Diphyllobothrium Latum Infection 

  • Author: Robert W Tolan Jr, MD; Chief Editor: Russell W Steele, MD   more...
 
Updated: Jan 9, 2012
 

Background

Human intestinal infection with the fish tapeworm, or broad tapeworm, Diphyllobothrium latum is called diphyllobothriasis. It is endemic in areas where humans frequently consume raw or pickled fish. The associated symptomatology is nonspecific, but megaloblastic anemia is a well-described complication. Diphyllobothrium nihonkaiense infection also causes human diphyllobothriasis, largely clinically indistinguishable from that caused by D latum. The organisms are morphologically indistinguishable, but can be differentiated via polymerase chain reaction (PCR)-based DNA sequence analysis of specific genes. This organism is commonly found in salmon and likely is the cause of all diphyllobothriasis in Japan.[1]

Next

Pathophysiology

Cestodes, a subclass of the phylum Platyhelminthes, has 2 orders that infect humans: Cyclophyllidae and Pseudophyllidea. One of the main differentiating points between the genera of the 2 orders is that the genera of the first order typically have a scolex with 4 suckers whereas the genera of the second order have a scolex with 2 opposing sucking grooves. Another important point of differentiation is that Cyclophyllidae has 2 hosts in its life cycle whereas Pseudophyllidea requires 3.

Diphyllobothrium is an example of the genera under Pseudophyllidea. The species of this genus are all parasites of fish-eating vertebrates. This article focuses on the organism D latum, for which humans are the definitive host.

A full-grown worm can vary in size from 1-15 m and is the longest human tapeworm. It consists of up to 3000-4000 proglottids. The scolex, as mentioned, has 2 sucking grooves, also called bothria. Proglottids are typically wider than they are long (see following image), which is why D latum is called the broad tapeworm.

Microscopy. Proglottids of Diphyllobothrium latum.Microscopy. Proglottids of Diphyllobothrium latum.

In the gravid state, the worms have a distinctive rosette-like uterus in the center. The uterus sheds eggs into the fecal stream via a ventral pore. The eggs are unembryonated when shed and are operculated. The eggs (see following image) must reach fresh water that contains crustaceans and fish to act as the intermediate host to complete their maturation.

Microscopy. Egg of Diphyllobothrium latum with arrMicroscopy. Egg of Diphyllobothrium latum with arrow pointing to operculum.

During a 10-day to 14-day period, they transform into ciliated embryos with 6 hooks (called coracidia) that are released from the open opercula. The coracidia must then be eaten within a short period by crustacea (eg, copepods or water fleas) to undergo the next stage of maturation, which is the first-stage larva or procercoid.

Life cycle of Diphyllobothrium.Life cycle of Diphyllobothrium.

Copepods that contain the procercoid are then eaten by freshwater fish that function as the second intermediate host. Here, the procercoid matures into the plerocercoid or sparganum in the fish muscle fibers. Infected fish are then consumed by progressively larger fish, with the sparganum being passed on, until, finally, the fish is consumed by a human, the definitive host. During the next 3-5 weeks, the plerocercoid larva matures into an adult that can live for up to 10 years.

Thus, the plerocercoid larva infects humans who have ingested heated or frozen freshwater fish. Because of the requirement for intermediate hosts, direct human-to-human transmission does not occur; therefore, no isolation measures are required.

Although actual results of infestation are not well studied, megaloblastic anemia can result. Some scientists believe the mechanism is related to the site of the worm, its marked affinity for vitamin B-12, and, perhaps, an underlying vitamin B-12 deficiency in patients at the outset.

One study demonstrated that when a mixture of vitamin B-12 and gastric juice were placed in the ileum, a hematological remission resulted. This did not occur when the mixture was taken orally. This suggests that D latum preferentially absorbs vitamin B-12 in the blood, preventing vitamin B-12-IF complexes from reaching receptors in the small bowel.

Previous
Next

Epidemiology

Frequency

United States

Outbreaks associated with the increased popularity and availability of fresh salmon (as opposed to canned or frozen salmon) have been described. Also, infestation is related to the popularity of delicacies such as sushi.[2]

International

This is a worldwide disease that affects people near freshwater and appropriate intermediate hosts. Areas where consumption of raw/precooked fish is popular tend to have endemicity (eg, northern Europe, Scandinavia).

Mortality/Morbidity

Occasionally, infestation can lead to severe megaloblastic anemia or intestinal obstruction. No figures are available to assess morbidity from this disease. Outcomes with single-dose therapy are excellent.

Race

No racial predilection has been reported.

Sex

No gender predilection has been documented.

Age

No age predilection has been reported.

Previous
Proceed to Clinical Presentation
 
 
Contributor Information and Disclosures
Author

Robert W Tolan Jr, MD  Chief, Division of Allergy, Immunology and Infectious Diseases, The Children's Hospital at Saint Peter's University Hospital; Clinical Associate Professor of Pediatrics, Drexel University College of Medicine

Robert W Tolan Jr, MD is a member of the following medical societies: American Academy of Pediatrics, American Medical Association, American Society for Microbiology, American Society of Tropical Medicine and Hygiene, Infectious Diseases Society of America, Pediatric Infectious Diseases Society, Phi Beta Kappa, and Physicians for Social Responsibility

Disclosure: Novartis Honoraria Speaking and teaching

Coauthor(s)

Alia Rai, MD  Adolescent Medicine Fellow, Department of Pediatrics, West Virginia University

Alia Rai, MD is a member of the following medical societies: American Academy of Pediatrics, American Medical Association, and Society for Adolescent Medicine

Disclosure: Nothing to disclose.

Martin Weisse, MD  Program Director, Associate Professor, Department of Pediatrics, West Virginia University

Martin Weisse, MD is a member of the following medical societies: Ambulatory Pediatric Association, American Academy of Pediatrics, and Pediatric Infectious Diseases Society

Disclosure: Nothing to disclose.

Specialty Editor Board

Ashir Kumar, MD, MBBS, FAAP  Professor Emeritus, Department of Pediatrics and Human Development, Michigan State University College of Human Medicine

Ashir Kumar, MD, MBBS, FAAP is a member of the following medical societies: American Association of Physicians of Indian Origin and Infectious Diseases Society of America

Disclosure: Nothing to disclose.

Mary L Windle, PharmD  Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Nothing to disclose.

Martin Weisse, MD  Program Director, Associate Professor, Department of Pediatrics, West Virginia University

Martin Weisse, MD is a member of the following medical societies: Ambulatory Pediatric Association, American Academy of Pediatrics, and Pediatric Infectious Diseases Society

Disclosure: Nothing to disclose.

Daniel Rauch, MD, FAAP  Director, Pediatric Hospitalist Program, Associate Professor, Department of Pediatrics, New York University School of Medicine

Daniel Rauch, MD, FAAP is a member of the following medical societies: Ambulatory Pediatric Association, American Academy of Pediatrics, and Society of Hospital Medicine

Disclosure: Baxter Honoraria Consulting

Chief Editor

Russell W Steele, MD  Head, Division of Pediatric Infectious Diseases, Ochsner Children's Health Center; Clinical Professor, Department of Pediatrics, Tulane University School of Medicine

Russell W Steele, MD is a member of the following medical societies: American Academy of Pediatrics, American Association of Immunologists, American Pediatric Society, American Society for Microbiology, Infectious Diseases Society of America, Louisiana State Medical Society, Pediatric Infectious Diseases Society, Society for Pediatric Research, and Southern Medical Association

Disclosure: Nothing to disclose.

References

  1. Arizono N, Shedko M, Yamada M, Uchikawa R, Tegoshi T, Takeda K, et al. Mitochondrial DNA divergence in populations of the tapeworm Diphyllobothrium nihonkaiense and its phylogenetic relationship with Diphyllobothrium klebanovskii. Parasitol Int. Mar 2009;58(1):22-8. [Medline].

  2. Church C, Neill A, Schotthoefer AM. Intestinal infections in humans in the Rocky Mountain region, United States. J Parasitol. Feb 2010;96(1):194-6. [Medline].

  3. Lal S, Steinhart AH. Diphyllobothrium latum: a case of an incidental finding. World J Gastroenterol. Mar 28 2007;13(12):1875-6. [Medline].

  4. Wicht B, Yanagida T, Scholz T, Ito A, Jimenez JA, Brabec J. Multiplex PCR for differential identification of broad tapeworms (Cestoda: Diphyllobothrium) infecting humans. J Clin Microbiol. Sep 2010;48(9):3111-6. [Medline]. [Full Text].

  5. Soga K, Sakagami J, Handa O, Konishi H, Wakabayashi N, Yagi N, et al. Long fish tapeworm in the intestine: an in situ observation by capsule endoscopy. Intern Med. 2011;50(4):325-7. [Medline].

  6. Craig P, Ito A. Intestinal cestodes. Curr Opin Infect Dis. Oct 2007;20(5):524-32. [Medline].

  7. American Academy of Pediatrics. Other tapeworm infections (including hydatid disease). In: Red Book: 2009 Report of the Committee on Infectious Diseases. 28th. Elk Grove Village, IL: American Academy of Pediatrics; 2009:654-5.

  8. Blanton R. Taeniasis and Diphyllobothriasis. In: Nelson Textbook of Pediatrics. 15th ed. Philadelphia, Pa: WB Saunders; 993-5.

  9. Bylund BG. Diphyllobothruim latum. In: Akuffo H, Linder E, Ljungstrom I, Wahlgren M. Parasites of the Colder Climates. London and New York: Taylor & Francis; 2003:169-176.

  10. Byun TJ, Han DS, Ahn SB, Cho HS, Eun CS, Ryu JS, et al. Multiple colonic aphthoid ulcers caused by Diphyllobothrium latum infection. Endoscopy. 2009;41 Suppl 2:E181-2. [Medline].

  11. Cabello FC. Salmon aquaculture and transmission of the fish tapeworm. Emerg Infect Dis. Jan 2007;13(1):169-71. [Medline].

  12. Church C, Neill A, Schotthoefer A. Seasonality of Parasitic Gut Infections in Humans in the Rocky Mountain Region, USA. J Parasitol. Oct 6 2009;1. [Medline].

  13. Dorny P, Praet N, Deckers N, Gabriel S. Emerging food-borne parasites. Vet Parasitol. Aug 7 2009;163(3):196-206. [Medline].

  14. Fuchizaki U, Ohta H, Sugimoto T. Diphyllobothriasis. Lancet Infect Dis. Jan 2003;3(1):32. [Medline].

  15. Hutchinson JW, Bass JW, Demers DM, Myers GB. Diphyllobothriasis after eating raw salmon. Hawaii Med J. Jul 1997;56(7):176-7. [Medline].

  16. Jackson Y, Pastore R, Sudre P, Loutan L, Chappuis F. Diphyllobothrium latum outbreak from marinated raw perch, Lake Geneva, Switzerland. Emerg Infect Dis. Dec 2007;13(12):1957-8. [Medline].

  17. Jeon HK, Kim KH, Huh S, et al. Morphologic and genetic identification of Diphyllobothrium nihonkaiense in Korea. Korean J Parasitol. Dec 2009;47(4):369-75. [Medline]. [Full Text].

  18. Kim JH, Lee JH. Images in clinical medicine. Diphyllobothrium latum during colonoscopy. N Engl J Med. Mar 18 2010;362(11):e40. [Medline].

  19. Kim YJ, Lee MW, Jeon HJ, Yi JG, Paick SH, Kim HG. Sparganosis in the scrotum: sonographic findings. J Ultrasound Med. Jan 2007;26(1):129-31. [Medline].

  20. Lee EB, Song JH, Park NS, Kang BK, Lee HS, Han YJ. A case of Diphyllobothrium latum infection with a brief review of diphyllobothriasis in the Republic of Korea. Korean J Parasitol. Sep 2007;45(3):219-23. [Medline].

  21. Lee MK, Hong SJ, Kim HR. Seroprevalence of tissue invading parasitic infections diagnosed by ELISA in Korea. J Korean Med Sci. Sep 2010;25(9):1272-6. [Medline]. [Full Text].

  22. Lou HY, Tsai PC, Chang CC, et al. A case of human diphyllobothriasis in northern Taiwan after eating raw fish fillets. J Microbiol Immunol Infect. Oct 2007;40(5):452-6. [Medline].

  23. Mercado R, Yamasaki H, Kato M, et al. Molecular identification of the Diphyllobothrium species causing diphyllobothriasis in Chilean patients. Parasitol Res. Mar 2010;106(4):995-1000. [Medline].

  24. Raether W, Hanel H. Epidemiology, clinical manifestations and diagnosis of zoonotic cestode infections: an update. Parasitol Res. Nov 2003;91(5):412-38. [Medline].

  25. Rausch RL, Adams AM, Margolis L. Identity of Diphyllobothrium spp. (Cestoda: Diphyllobothriidae) from sea lions and people along the Pacific coast of South America. J Parasitol. Apr 2010;96(2):359-65. [Medline].

  26. Sampaio JL, de Andrade VP, Lucas Mda C, et al. Diphyllobothriasis, Brazil. Emerg Infect Dis. Oct 2005;11(10):1598-600. [Medline].

  27. Sarukawa S, Kawanabe T, Yagasaki A, Shimizu A, Shimada S. Case of subcutaneous sparganosis: use of imaging in definitive preoperative diagnosis. J Dermatol. Sep 2007;34(9):654-7. [Medline].

  28. Schantz PM, Tanowitz HB, Wittner M. Tapeworm infections. In: Hunter's Tropical Medicine and Emerging Infectious Diseases. 8th ed. Philadelphia, Pa: WB Saunders; 852-4.

  29. Scholz T, Garcia HH, Kuchta R, Wicht B. Update on the human broad tapeworm (genus diphyllobothrium), including clinical relevance. Clin Microbiol Rev. Jan 2009;22(1):146-60, Table of Contents. [Medline].

  30. Skerikova A, Brabec J, Kuchta R, et al. Is the human-infecting Diphyllobothrium pacificum a valid species or just a South American population of the holarctic fish broad tapeworm, D. latum?. Am J Trop Med Hyg. Aug 2006;75(2):307-10. [Medline].

  31. Stanciu C, Trifan A, Singeap AM, Sfarti C, Cojocariu C, Luca M. Diphyllobothrium latum identified by capsule endoscopy--an unusual cause of iron-deficiency anemia. J Gastrointestin Liver Dis. Jun 2009;18(2):142. [Medline].

  32. Taketoma CK, Hodding JH, Kraus DM. Tapeworm. In: Pediatric Dosage Handbook. 7th ed. Lexi-Comp; 2000.

  33. Turner JA. Cestodes. In: Feigin RD, Cherry JD, eds. Textbook of Pediatric Infectious Disease. Vol 2. 5th ed. Philadelphia, Pa: WB Saunders; 2004:2797-816.

  34. von Bonsdorff B, Gordin R. Castle's test (with vitamin B12 and normal gastric juice) in the ileum in patients with genuine and patients with tapeworm pernicious anaemia. Acta Med Scand. 1980;208(3):193-7. [Medline].

  35. Vuylsteke P, Bertrand C, Verhoef GE, Vandenberghe P. Case of megaloblastic anemia caused by intestinal taeniasis. Ann Hematol. Jul 2004;83(7):487-8. [Medline].

  36. Weisse ME, Raszka WV. Cestode infection in children. Adv Pediatr Infect Dis. 1996;12:109-53. [Medline].

  37. Wiwanitkit V. A review of human sparganosis in Thailand. Int J Infect Dis. Nov 2005;9(6):312-6. [Medline].

  38. Yamasaki H, Kuramochi T. A case of Diphyllobothrium nihonkaiense infection possibly linked to salmon consumption in New Zealand. Parasitol Res. Aug 2009;105(2):583-6. [Medline].

  39. Yanagida T, Matsuoka H, Kanai T, Nakao M, Ito A. Anomalous segmentation of Diphyllobothrium nihonkaiense. Parasitol Int. Jun 2010;59(2):268-70. [Medline].

  40. Yera H, Nicoulaud J, Dupouy-Camet J. Use of nuclear and mitochondrial DNA PCR and sequencing for molecular identification of Diphyllobothrium isolates potentially infective for humans. Parasite. Sep 2008;15(3):402-7. [Medline].

  41. Youn H. Review of zoonotic parasites in medical and veterinary fields in the Republic of Korea. Korean J Parasitol. Oct 2009;47 Suppl:S133-41. [Medline]. [Full Text].

 
Previous
Next
 
Life cycle of Diphyllobothrium.
Microscopy. Egg of Diphyllobothrium latum with arrow pointing to operculum.
Microscopy. Proglottids of Diphyllobothrium latum.
 
 
 
All material on this website is protected by copyright, Copyright © 1994-2012 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.

DISCLAIMER: The content of this Website is not influenced by sponsors. The site is designed primarily for use by qualified physicians and other medical professionals. The information contained herein should NOT be used as a substitute for the advice of an appropriately qualified and licensed physician or other health care provider. The information provided here is for educational and informational purposes only. In no way should it be considered as offering medical advice. Please check with a physician if you suspect you are ill.