1. Parasitology

2. Nematohelminthes (Round worms)
Helminthology
Platyhelminthes
(Flat worms)
Nematohelminthes (Round worms)
Trematoda (Flukes)
Nematoda
Ceastoda
(Tape worms)

3. Define:
Disease:-

4. Class Cestoda (Tape Worms)

5. Cestoda

6. In this course we study:
Taenia solium & Taenia saginata
Hymenolepis nana & Hymenolepis diminuta
Echinococcus granulosus.

7. Hymenolepis nana & Hymenolepis diminuta

8. Dwarf tapeworm Rat tapeworm Cosmopolitan Hymenolepiasis
Name:
Hymenolepis nana
Hymenolepis diminuta
Definition:
Dwarf tapeworm
Rat tapeworm
Distribution:
Cosmopolitan
Disease:
Hymenolepiasis
Pathogenicity:
Usually asymptomatic.
In case of severe, heavy infection there may be abdominal pain, enteritis and diarrhoea.
Anaemia & nervous symptoms can occur in children.
Generally there is no effect on the host.

11. Definitive host: Intermediate host: Diagnostic stage:
Hymenolepis nana
Hymenolepis diminuta
Habitat:
Definitive host:
Intermediate host:
Diagnostic stage:

12. Human occasionally rodents.
Hymenolepis nana
Hymenolepis diminuta
Habitat:
Adult:
Mainly in small intestine of human (especially children) ,rats and mice.
In ileum of rats and mice, occasionally in human.
Larva:
In insects principally
Fleas and cockroaches.
Definitive host:
Human occasionally rodents.
Rats & mice; human & dogs are accidental hosts.

13. No intermediate host is required ( rodents).
Hymenolepis nana
Hymenolepis diminuta
Intermediate host:
No intermediate host is required ( rodents).
Insects including fleas, beetles, cockroaches and other.
Diagnostic stage:
Eggs in stool.
Adult worms and proglottides are rarely seen in stool.

14. Infective stage: Mode of infection: Treatment:
Hymenolepis nana
Hymenolepis diminuta
Infective stage:
Mode of infection:
Treatment:

15. Cysticercoid larvae in body cavity of insect.
Hymenolepis nana
Hymenolepis diminuta
Infective stage:
Eggs passed in feces.
Cysticercoid larvae in body cavity of insect.
Mode of infection:
Ingestion of eggs or by Internal autoinfection.
By ingestion of cysticercoid larvae in body cavity of insect via rodent or human

16. * Collective treatment is required for all children of the family.
Hymenolepis nana
Hymenolepis diminuta
Treatment:
Niclosamide (Yomesan®) 4 tablets before meal first day and 2 tablets daily for other 5 days. Praziquantel one dose is sufficient.
* Collective treatment is required for all children of the family.

17. Adult worm of Hymenolepis nana
Adult worm is small thread like, 2-3 cm in length.
It consist of over 100 segments all of which are broader than long.

18. Gravid segment of Hymenolepis diminuta
* Uterine branches is hardly visible.
* Each segment 1 mm wide.

19. of Hymenolepis diminuta
(1) Mature segment (2) Gravid segment
of Hymenolepis diminuta

20. Hymenolepis nana Scolex
The scolex has four suckers which are not visible in this plane of focus (two are marked by *), and an armed rostellum that is clearly visible. 

21. Hymenolepis diminuta Scolex 
The scolex has four suckers.
(two are marked by the *), but no hooks [absence of an armed rostellum].

22. Echinococcus granulosus

23. Echinococcus granulosus
Name:
Echinococcus granulosus
Definition:
Dog tape worm , or hydated tape worm.
Distribution:
In the Mediterranean region
Disease:
Echinococcosis , unilocular hydated cyst.
Morphology:
Scolex: with 4 suckers and a double hook crowned rostellum.
The rest of the body consists of 3 proglottides giving the worm a length of mm.

25. Echinococcus granulosus
Habitat:
Definitive host:
Intermediate host:

26. Echinococcus granulosus
Habitat:
Adult:
In small intestine of doges, foxes and wolves.
Larva:
As hydated cysts in intermediate host tissues.
Definitive host:
Carnivores as doges, foxes and wolves.
Intermediate host:
Cattle, sheep, various herbivores.
Human can be a dead end intermediate host.

27. Echinococcus granulosus
Diagnostic stage:
Infective stage:
Mode of infection:

28. Echinococcus granulosus
Diagnostic stage:
In case of human the hydated cyst diagnosed by X- rays, CT or ultrasound.
Infective stage:
For human eggs of Echinococcus granulosus.
Mode of infection:
Ingestion of eggs from soil, food or drinks contaminated with dog feces or from dog fur.

29. Echinococcus granulosus
Treatment:
Prevention:

30. Echinococcus granulosus
Treatment:
Surgical removal of hydated cysts.
Long time therapy with albendazole (Alzental ® ,Vermizole ®) is found to reduce the cyst growth.
Prevention:
Keeping dogs away from slaughters house.
Proper hygiene concerning dogs.

31. Echinococcosis , unilocular hydated cyst
When the eggs of Echinococcus granulosus are ingested by the intermediate host, eggs hatch in small intestine giving the hooked embryo which penetrate intestinal mucosa and enters the blood circulation.
If the embryo escapes phagocytosis it resides in any tissue, lose its hooks and transforms to a cyst which is 10 mm in diameter. This process may take 5 months.

32. The cyst is composed from an external laminated hyaline membrane followed by a germinal layer. The cyst is filled with a sterile fluid Brood capsules are found inside the cyst, consisting of only germinal layer and protoscoleces. Ruptured capsule give thousands of protoscoleces at the bottom of the cyst, that is the hydated sand.
Hydated cysts can occur in bones, lungs, liver, brain or kidney.

33. Adjacent organs are affected due to presence of the cyst beside the inflammatory reaction against it. Cyst can cause blood vessels erosion and haemorrhage.
Removal of the cysts must done with care; sever allergic reactions or even dissemination of the hydated sand in the rupture. Cyst rupture could happen also in response to cough or muscle strain.

34. Adult worm of Echinococcus granulosus
It is the smallest cestode; composed only from 3 segments (proglottides).

38. Hydated sand