Dibothriocephalus latus is a pseudophyllidea cestode called chinese tapeworm have 2 suckers within scolex. it has 2 intermediate hosts first is the copepod and the second is fish before mammalian ( dog, cat, bear, human.. etc.) will eat it to become an adult tapeworm.

1. Dibothriocephalus latus

2. Hashemite University
Diphyllobothrium Latum
Course : Parasitology _ Advanced
Instructor : Dr. Naim Ismail
Presenter : Belal Abu Haneya

4. Outline
• Classification
• Introduction
• Morphology
• Symptoms
• Diagnosis
• Treatment

5. Classification

6. Comparison between Pseudophyllidea and
Cyclophyllidea
Pseudophyllidea Cyclophyllidea
Scolex 2 slit-like sucking 4 cup-shaped suckers
(bothria) with or without hooks
Genital on the flat surface on the margin of the
pore of the segment segment
Intermediate 2 1
host

7. Introduction
• Dibothriocephalus latus, or Diphyllobothrium latum is a fish
tapeworm
• most common in waters of the Northern Hemisphere
• infests humans and other mammals that eat fish, particularly
bears and dogs

8. • measuring 10 meters in length with 4000 proglottids *
• * a segment of a tapeworm containing both male and female reproductive organs

9. • Fertilized eggs pass from the host’s body in the feces
• In a water medium they develop into a hair-like larva
• eaten by tiny crustaceans, which, in turn, are eaten by a fish

10. Morphology
• The adult worm is composed of three segments:
* the scolex (head) * the neck * the lower body
• Each side of the scolex has a slit-like groove, which is
a **bothrium for attachment to the intestine.
• The scolex attaches to the neck, or proliferative region.
• From the neck grow many proglottid segments which contain
the reproductive organs of the worm.
* elongate, dorsal or ventral longitudinal grooves on the scolex of cestoda

15. • D. latum is the longest tapeworm in humans, averaging ten
meters long. Adults can shed up to a million eggs a day.
• In adults, proglottids are wider than they are long (hence the
name broad tapeworm).
• As in all pseudophyllid cestodes, the genital pores open
midventrally.

16. Diphyllobothrium latum at Tadas
Ivanauskas Zoological Museum

17. Life cycle

18. Clinical symptoms
• Symptoms of diphyllobothriasis are generally mild,
and can include
Diarrhea
Abdominal pain
Vomiting
weight loss
Fatigue
Constipation
Discomfort

20. • Approximately four out of five cases are asymptomatic and
may go many years without being detected
• In a small number of cases, this leads to severe vitamin
B12 deficiency due to the parasite absorbing 80% or more of
the host’s B12 intake
• anemia can also lead to subtle demyelinative neurological
symptoms

21. Diagnosis
• Diagnosis is usually made by ..
* identifying proglottid segments
* characteristic eggs in the feces
• these simple diagnostic techniques are able to identify the
nature of the infection to the genus level, which is usually
sufficient in a clinical setting

22. • when the species needs to be determined (in
epidemiological studies)
restriction fragment length polymorphisms ( RFLP )can
be effectively used
* PCR can be performed on samples of purified eggs
* or native fecal samples following sonication of the eggs
to release their contents

23. • Another interesting potential diagnostic tool and treatment is
• the contrast medium, Gastrografin
• introduced into the duodenum
• allows both visualization of the parasite
• shown to cause detachment and passing of the whole worm.

24. Treatment
• The standard treatment for diphyllobothriasis, as well as many
other tapeworm infections is
• single dose of Praziquantel, 5–10 mg/kg PO once for both
adults and children
• An alternative treatment is Niclosamide, 2 g PO once for
adults or 50 mg/kg PO once for children

25. • Praziquantel is not FDA approved for this indication
and
• Niclosamide is not available for human use in the
United States.

26. Epidemiology
• People at high risk for infection have traditionally been those
who regularly consume raw fish.
• Many regional cuisines include raw or undercooked food
including
• sushi and sashimi in Japanese cuisine
• carpaccio di persico in Italian
• tartare maison in French-speaking populations
• ceviche in Latin American cuisine
• marinated herring in Scandinavia.

27. • With emigration and globalization..
• the practice of eating raw fish in these and other
dishes has brought diphyllobothriasis to new parts of
the world and created new endemic foci of disease

28. References
• Muratov, IV; Posokhov, PS (1988). "Causative agent of human
diphyllobothriasis--Diphyllobothrium klebanovskii sp.
n.". Parazitologiia 22 (2): 165–70
• Yamane, Y; Kamo, H; Bylund, G; Wikgren, BJ (1986). "Diphyllobothrium
nihonkaiense sp. nov (Cestoda: Diphyllobothriidae)---revised identification
of Japanese broad tapeworm". Shimane J Med Sci 10: 29–48