1. Umm Al-Qura University
بسم الله الرحمن الرحيم
Umm Al-Qura University
Health Sciences College at Al-Leith
Department of Public Health
Lecture (4)

2. Giardia lamblia

3. Objectives 1/ Know of Giardia lamblia classification
and Geographical distribution.
2/ Study of Giardia lamblia External Morphology,Habitat,Life cycle, Mode of Transmission,Pathogenicity.
3/ Show Symptoms of Giardiasis disease.
4/ Show Laboratory diagnosis of Giardia lamblia.
5/ Know Treatment and prevention.

4. Giardia trophozoite

6. Class: Zoomastigophorea
The parasites belonging to this class, movement is carried out by means of flagellum or a number of flagella.

7. Intestinal flagellates
Giardia lamblia (giardia intestinalis)
Geographic distribution:
Worldwide it occurs in all age groups, though incidence appear to be higher in children.

8. Habitat:
Duodenum and the upper part of jejunum in man.
Morphology:
It exists in two forms:
1-Trophozoite form.
2- cyst form.

9. 1- Trophozoite:
This is the vegetative (actually feeding) stage which is responsible for the colonization of the parasite in the human beings.

11. Giardia trophozoite

12. Trophozoite measuring about 10 – 20 um in length, 6 – 15 um in width and 1 – 3 um in thickness. The dorsal surface is convex and the ventral surface is concave.

13. Giardia trophozoite

14. Giardia trophozoite

15. Giardia trophozoite

16. Giardia trophozoite

17. Giardia trophozoite

18. 2-Cyst:
the cysts are oval, measuring 8 – 14 um in length and 6 – 10 um in width.
They contain four nuclei. The cysts are passed in the faeces.
Cysts are the infective stages to man.

20. Giardia cyst

21. Giardia cyst

22. Giardia cyst

23. Giardia cyst

25. Lifecycle:
Cysts transmitted through a water source. Which introduce into the human body by oral route through Contaminatted water and food.

26. Acidic environment of the stomach initiates excystation which is completed in duodenum and new trophozoites make their home among the intestinal villi.

30. Clinical manifestations:
1- Diarrhea.
2- Greasy stools.
3- Weight loss.
4- Abdominal cramps.
5- Headache.
6- Mucus in stools.
7- Low grade fever.

31. Diagnosis
Examination of stool under the microscope for cysts or trophozoites;
however, it takes three samples of stool to diagnose 90% of cases.

33. Microscope

35. Cover slip and slide

38. Iodine solution

42. Microscope

43. Treatment: 1- Metronidazole. 2- Tinidazole. 3- Flucazolidone.
4- Mepacrine.

44. Prevention
1- Introduction of adequate sanitation measures and education about the routes of transmission. 2- Avoid eating raw vegetables grown by sewerage irrigation and night soil. 3- Always wash hands with soap after going to the toilet before eating food.

45. Thanks
Radia 45