Diphyllobothrium Latum (Broad tape worm, Fish tape worm)

1. DiphyllobothriumLatum(Broad tape worm, Fish tape worm) By:Amin Asadian

2. Taxonomy • Phylum: Platyhelminthes • Class: Cestoidea • Subclass: Cestoda • Order: Pseudophyllidea

3. Geographical Distribution Lake regions in Europe, America, CentralAfrica, Russia and Japan

4. Morphology • Length: 3-10 m • Scolex: elongated, almond shaped, 2 bothria

5. Mature segment (no gravid segment): -Broader than long • Ventral C.G.P • Multiple testes • Bilobed ovary • Rosette shaped uterus • Vitelline glands Morphology

6. Proglottid of D. latum

7. Life Cycle

8. D. latum Egg Scolex Proglottids

9. Pathogenesis and Clinical picture 1- Asymptomatic 2- Intestinal disturbances 3- Neurological manifestations 4- Intestinal obstruction 5- Pernicious anaemia

10. 1- Detect eggs and segments in faeces 2- Anaemia in blood picture Diagnosis

11. 1- Praziquantel 2- Niclosamide 3- Vitamin B12 Treatment

12. 1- Sanitary disposal of excreta and sewage 2- Proper cooking/ freezing of fish 3- Treat infected patients 4- Health education Prevention and Control

13. Hymenolepis nana also known as Vampirolepis nana With Special Guest Hymenolepis diminuta

14. Kingdom: Animalia Family: HymenolepididaeGenus: Hymenolepis Taxonomy P hylum:Platyhelminthes Class:Cestoda Order:Cyclophyllidea

15. Only two species of this family can infect humans. • Hymenolepis nana • Hymenolepis diminuta • Hymenolepiasis is the term when a human is infected with either H. diminuta or H. Nana Hymenolepididae • Hymenolepis nana Hymenolepis diminuta

16. H. nana is commonly called the dwarf tapeworm. Nanos = dwarf • H. nana is the most common tapeworm in humans worldwide. • H. nana has been called Vampirolepis nana because H. diminuta has an unarmed rostellum and the rostellar hooks of H. nana were viewed as the basis for putting it in a separate genus. Hymenolepis nana

17. also known as rat tapeworm, is a species of Hymenolepistapeworm that causes hymenolepiasis. It has slightly bigger eggs and proglottids than H. nana and infects mammals using insects as intermediate hosts. The adult structure is 20 to 60 cm long and the mature proglottid is similar to that of H. nana, except it is larger. • H. diminuta is prevalent worldwide, but only a few hundred human cases have been reported. Few cases have ever been reported in Australia, United States, Spain, and Italy. In countries such as Malaysia, Thailand, Jamaica, Indonesia, the prevalence is higher. Hymenolepis diminuta

18. Definitive host • Human • Mice • Rats • Intermediate host (Optional) • Fleas • Beetles Hosts of H. nana The only cestode that parasitizes humans without requiring an intermediate host.

19. Definitive host • Rats • Dogs • Humans • Intermediate host • Grain beetle • Lots of other arthropods Hosts of H. diminuta Only when the intermediate host is ingested by the definitive host will H. diminuta mature.

20. Geographical Distribution Worldwide *Frequently found in temperate zones Rates of infection for H. nana in humans. * 1% in southern United States * 34% in Argentina * 46% Sicily

21. Morphology H. nana • Adult worm are only 10-45 mm long and 0.5-1 mm wide • Neck is long and slender • They have 100-200 segments that are wider then they are long

22. Morphology H. nana • Eggs generally measure between 30 to 47 microns in diameter. • They are round to oval, and should contain a six-hooked oncosphere. • They have polar filaments that lie between the eggshell and the oncosphere.

23. Morphology H. nana • Scolex bears a retractable rostellum armed with a single circle of 20-30 hooks. • The scolex also has four suckers. • Genital pores are unilateral (side of the segment) • Each mature segment contains three testes

24. Morphology H. diminuta • Grows to be about 20 - 60cm or more in length. • Consists of up to 1000 proglottids that are approximately four times as wide as they are long. • Each proglottid contains three round testes, a bi-lobed ovary, a compact vitelline gland and a large uterus opening to a lateral genital pore. • The scolex has four suckers and a retractable rostellum that does not have hooks.

25. Morphology H. diminuta • Eggs are a round or slightly oval and yellowish brown in color. • Eggs are larger at 60 - 80µm in diameter than H. nana eggs. • The oncosphere (hexacanth) has six hooks (of which at least four are visible in top photo). • Can produce over 250,000 eggs per day. Which is one hundred million eggs in slightly over a year.

26. The most characteristic morphological feature of the group is the small number of testes. • The combination of few testes, usually unilateral genital pores, and a large external seminal vesicle permits easy recognition of the family. Morphology

27. Life Cycle H. nana

28. Eggs are ingested by an arthropod intermediate host where they develop into cysticercoids, which can infect humans or rodents upon ingestion. • When eggs are ingested (food, water, hands) the oncospheres contained in the eggs are released. The oncospheres penetrate the intestinal villus and develop into cysticercoid larvae. • Upon rupture of the villus, the cysticercoids return to the intestinal lumen, evaginate their scoleces and attach to the intestinal mucosa where they develop into adults that reside in the ileal portion of the small intestine producing gravid proglottids. Life Cycle H. nana

29. Eggs are passed in the feces when released from proglottids after the proglottids disintegrate in the small intestine.  • An alternate mode of infection consists of internal autoinfection, where the eggs release their oncospheres, which penetrates the villus continuing the infective cycle without passage through the external environment. • The life span of adult worms is 4 to 6 weeks, but internal autoinfection allows the infection to persist for years. • Eggs of H. nana are immediately infective when passed with the stool and cannot survive more than 10 days in the external environment. Life Cycle H. nana

30. Life cycle of H. diminuta Matures in about 20 days.

31. From H. nana….. • By accidentally ingesting tapeworm eggs. • by ingesting fecally contaminated foods and water • by touching your mouth with contaminated fingers • by ingesting contaminated soil. • Once you are infected, the dwarf tapeworm may cause auto infection where the tapeworm may reproduce inside the body and continue the infection. How do you get infected? From H. diminuta …. *Human infection results from eating such foods as dried fruits and precooked breakfast cereals in which the infected grain insects larvae are present. *Eating an intermediate host of H. diminuta.

32. Light infections are asymptomatic. • When large numbers of worms are present, they may give rise to abdominal pain, diarrhea, headache, and various non-specific symptoms. (This is the same for H. diminuta in humans) • H. nana can be deadly in children or people with a weak immune system. The larva will burrow into the walls of the intestine and absorb all the nutrition. • Dehydration can result from prolonged diarrhea. Pathogenesisin H. nana

33. Diagnosis and Treatment • Detection of eggs in feces. • Praziquantel acts very rapidly. • Expect full recovery following treatment. • Seeing tapeworm in intestine. • Fecal float Fecal smear H. nana

34. Prevention • Good hygiene • Elimination of rats and mice • A well-balanced diet to promote resistance to infection • Public health and sanitation programs

35. Pictures Scolex of H. diminuta Scolex of H. nana

36. Pictures Cysticercoid of H. diminuta.

37. Thank you