1. Diphyllobothrium Latum (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, Central Africa, Russia and Japan

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

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

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

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

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

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

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

15. Hymenolepididae 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
Hymenolepis nana
Hymenolepis diminuta

16. Hymenolepis nana
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.

17. Hymenolepis diminuta
also known as rat tapeworm, is a species of Hymenolepis tapeworm 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.

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

19. Hosts of H. diminuta Definitive host Intermediate host Rats Dogs
Humans
Intermediate host
Grain beetle
Lots of other arthropods
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 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 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 µm 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. Morphology
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.

27. Life Cycle H. nana

28. Life Cycle H. nana
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.

29. Life Cycle H. nana
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.

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

31. How do you get infected? 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.
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. Pathogenesis in H. nana 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.

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