Giardia lamblia Giardia lamblia Intestinal flagellate lives in

Giardia lamblia

Giardia lamblia Intestinal flagellate lives in duodenum and jejunum Giardiasis, diarrhea in man

1. Morphology and life cycle Two stages: Trophozoite and cyst 1. 1 Trophozoite Pear-shaped, a sucking disc, bilaterally symmetrical, with two nuclei, two axosatyle, two median bodies, four pairs of flagella (motile).

Dorsal surface is convex, ventral surface is concave With a broad rounded anterior end a tapering posterior end Nuclei Sucker Median body Front side flagella Behind side flagella ventral flagella Ventral surface Tail flagella Lateral surface

Giardia – Electron micrographs

Giardia – Ventral Disc

1. 2 Cyst Oval in shape Thick cyst wall and cytoplasma The immature Cysts have two Nuclei.

Giardiasis Giardia intestinalis =(lamblia) Trophozoites Cysts

The mature cysts have four nuclei. The mature cyst is the infective stage of Giardia lamblia. Mature cyst The mature cysts have strong resistance to the environment.

The cysts of Giardia lamblia

A single host: the man. Two stages: Trophozoite and cyst Four nucleated mature cyst is the infective form. Trophozoites browse on the mucosal surface by an oval sucker, multiplied asexually by binary fission.

Giardia – Life cycle

1. 3 Life cycle of Giardia lamblia Contaminate water and food Multiplied by binary fission Outside Trophozoites Diarrhea Mature Cysts Stool Trophozoites Cysts Duodenum, upper ileum, gall bladder Outside The lower portion of ileum or colon

2. Pathogenesis and symptoms G. lamblia inhabits in the duodenum and upper ileum Trophozoites are attached to the mucosa surface by sucker, reproduced by binary fission Histology: shortening of microvilli, elongation of crypts, and damaging the brush border of the absorptive cells Mechanical blockage of the intestinal mucosa, competition for nutrients, inflammation Diarrhea, abdominal pain, bloating, nausea, and vomiting

3. Diagnosis 3. 1 Pathogenic examination (1) Fecal examination Water-like feces: trophozoites Formed feces: cysts (2) Duodenal fluid or bile examination (3) Intestinal examination by gelatin capsule

3. Diagnosis 3. 2 Immunological diagnosis ELISA: enzyme-linked immunosoebent assay IFA: indirect fluorescent antibody

4. Epidemiology 4. 1 Distribution Worldwide distribution, endemic and epidemic. Traveler diarrhea Patients with variable immunodeficiency are increasingly susceptible to infection with Giardia.

4. Epidemiology 4. 2 Transmission source Persons whose feces containing cysts Monkeys and pigs can also be infected, the infected pig may be a source of human infection. 4. 3 Transmission Infected by drinking contaminated water eating contaminated food

Cysts have strong resistance Cysts can keep alive 10 or more days in feces; keep alive 12 days in the digestive tract of cockroach. Cysts are often waterborne, either by taking inadequately treated municipal water supplies of contaminated river or stream Giardiasis is more common in travelers, Immunodeficiency persons and buggers

5. Prevention and control 5. 1 Treat the patients and cyst carriers Metronidazole Tinidazole 5. 2 Treatment of the drinking water Suspect water should be boiled or adequately filtered to remove the infective cysts before drinking.

Giardia – Water borne transmission

Giardia - Arizona

Giardia – Zoonotic transmission?

Giardia - Genotypes

Giardia - Peru