1. Presented By: Dr. Shaymaa Abdalal Medical Parasitology Demonstrator
PROTOZOA
Presented By:
Dr. Shaymaa Abdalal
Medical Parasitology Demonstrator

2. INTESTINAL PROTOZOA

3. INTESTINAL PROTOZOA
Numerous protozoa inhabit the gastro-intestinal tract of humans .
Entamoeba histolytica can become a highly virulent and invasive organism that causes a potentially lethal systemic disease.
Giardia lamblia can cause severe acute diarrhea which may lead to a chronic diarrhea and nutritional disorders

4. INTESTINAL PROTOZOA
Intestinal protozoa are transmitted by the fecal-oral route .
exhibit similar life cycles consisting of a cyst stage and a trophozoite stage

5. INTESTINAL PROTOZOA

6. Giardia lamblia

7. Giardia lamblia Disease: GIARDIASIS Distribution:
worldwide distribution and is the most common protozoan isolated from human stools.

8. Giardia lamblia Definitive host : man
Habitat: upper portions of the small intestine.
Infective stage: cysts.

9. Giardia lamblia trophozoite

10. Giardia lamblia trophozoite
Characteristic features :
Two nuclei (Nu).
Central karyosomes (k).
median bodies (MB).
Axonemes (Ax) .
Four pairs of flagella (Fg).
An adhesive disk (AD).

11. Giardia lamblia trophozoite
Morphology:
Size : X 5-10µm.
Shape: Pear or Tear Drop

12. Giardia lamblia trophozoite

13. Giardia lamblia cyst

14. Giardia lamblia cyst Characteristic features : Four nuclei (Nu).
Axonemes (Ax) .
Median bodies (MB).
Well-defined wall (CW)

15. Giardia lamblia cyst
Morphology :
Size : 11-14X 6-10µm.
Shape: Oval

16. Giardia lamblia cyst

17. Entamoeba histolytica

18. Entamoeba histolytica
Disease:
amebiasis or amebic dysentery.
Distribution:
found throughout the world, they are more common in tropical countries or other areas with poor sanitary conditions.

19. Entamoeba histolytica
Definitive host : man
Habitat: large intestine.
Reservoir: no animal reservoirs.
Infective stage: cysts.

20. Entamoeba histolytica trophozoite

21. Entamoeba histolytica trophozoite
Characteristic features :
a finger-like
pseudopodium (psd) .
the ectoplasm (ecto).
cytoplasm has a granular
appearance the endoplasm (endo).
a glycogen vacuole (vac).
Nuclear (Nu).
chromatin and a centrally located
karyosome (ka).

22. Entamoeba histolytica trophozoite
Morphology :
Size : µm.
Shape: an amorphous shape .

23. Entamoeba histolytica trophozoite

24. Entamoeba histolytica cyst

25. Entamoeba histolytica cyst
Characteristic features :
Chromatoid bodies (cb) .
1-4 nuclei (Nu).
a glycogen vacuole (vac) .

26. Entamoeba histolytica cyst
Morphology :
Size : µm.
Shape: spherical shape .

27. Entamoeba histolytica cyst

28. Malaria

29. Malaria
Malaria is the 5th cause of death from infectious diseases worldwide (after respiratory infections, HIV/AIDS, diarrheal diseases, and tuberculosis) in low-income countries.
Malaria is the 2nd leading cause of death from infectious diseases in Africa, after HIV/AIDS.

30. Malaria
Disease: Malaria Distribution: Malaria today is usually restricted to tropical and subtropical areas

31. Malaria Intermediate Host: man
Vector (Definitive host) : femaleAnopheles mosquito
habitat: RBC`s
Infective stage: sporozoites .

32. P. vivax

33. P. vivax

34. P. Vivax ring stage

35. P. Vivax ring stage Diagnostic Points:
Red cells containing parasites are usually enlarged.
Schuffner's dots are frequently present in the red cells as shown above.
The mature ring forms tend to be large and coarse.
Developing forms are frequently present.

36. P. Vivax schizont stage

37. P. Vivax schizont stage schizonts of P. vivax are large and amoeboid.
Schizont large may almost fill the RBC`s.
Mature = 12 to 24 merozites.

38. P. falciparum

39. P. falciparum

40. P. falciparum ring stage

41. P. falciparum ring stage
Diagnostic Points:
Red Cells are not enlarged.
Rings appear fine and delicate and there may be several in one cell.
Some rings may have two chromatin dots.
Presence of marginal or applique forms.
No Trophosoite and schizont.

42. P. falciparum gametocyte stage

43. P. falciparum gametocyte stage
Gametocytes of P. falciparum. Figs : Macrogametocytes (female); Figs : Microgametocytes (male).
Illustrations from: Coatney GR, Collins WE, Warren M, Contacos PG. The Primate Malarias. Bethesda: U.S. Department of Health, Education and Welfare; 1971.

44. P. falciparum gametocyte stage
crescent- or sausage-shaped.
1.5 times the diameter of an RBC in length.
remnants of the host RBC can be seen; this is often referred to as Laveran's bib.

45. P. falciparum gametocyte stage
Gametocyte of P. falciparum in a thin blood smear, showing Laveran's bib. 

46. Key Morphological Differences
Falciparum
vivax
numerous rings
smaller rings
no trophozoites or schizonts
cresent-shaped gametocytes
enlarged erythrocyte
Schüffner's dots
'ameboid' trophozoite

47. Thank You