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Introduction of Giardiasis Giardia lamblia is a flagellated protozoan parasite that colonizes and reproduces in the small intestine, causing giardiasis. The parasite attaches to the epithelium by a ventral adhesive disc, and reproduces by binary fission. Giardiasis does not spread by the bloodstream, nor does it spread to other parts of the gastrointestinal tract, but remains confined to the lumen of the small intestine. Giardia trophozoites absorb their nutrients from the lumen of the small intestine, and are anaerobes. characteristic pattern resembles the familiar "smiley face" symbol. Their life cycle alternates between an actively swimming trophozoite and an infective, resistant cyst. That means giardia lamblia have two phases pathogen is trophozoites active stage and causeing giardiasis disease &cyst is infactive stageflagellatedprotozoanparasitegiardiasisepitheliumventralbinary fission gastrointestinal tractlumentrophozoitesanaerobessmileytrophozoitecyst

General characteristics  G. lamblia is a heart –shaped organism  Giardia have two nuclei, and have 8 flagella,nucleiflagella  lack both mitochondria and a Golgi apparatus.mitochondriaGolgi apparatus  they are now known to possess a complex endomembrane system as well as mitochondrial relics, called mitosomes. The mitosomes are not used in ATP synthesis the way mitochondria are, but are involved in the maturation of iron-sulfur proteins.mitosomesATPiron-sulfur proteins  reproduces by binary fission.binary fission  Measure between Mnin length and 5-9 Mn in width  They are anaerobes orgenismsanaerobes

Giardia lamblia

Morphology cyst 1)This phase has an oval (egg-shape) body in the shape 2)Measures between 8-12 µm in the length & 7-10 µm in the width 3)Contain four nuclei 4)Flagella and disk fragment that have been dissembled and a stored in the cyst trophozoite 1)It is Haif pear sheaped with 8 flagella 2)Measures between µm in the length & 5-9µm in the width 3)Contain two nuclei 4)Two axostyles arranged in bilateral symmetry 5)And two anteriorly located large suction disc

Life cycle of G. lamblia L ife cycle of Giardia lamblia. The life cycle begins with a non infective cyst being excreted with the feces of an infected individual infection life cycle occurs by the ingestion of cysts in contaminated water or food.in the small intestine, excystation releases trophozoites that multiply by longitudinal binary fission. The trophozoites remain in the lumen of the proximal small bowel where they can be free or attached to the mucosa by a ventral sucking disk. Encystation occurs when the parasites transit toward the colon,and cysts are he stage found in normal (non diarrheal ) feces.the cysts are hardy,can survive seyeral months in cold water,and are responsible or transmission,because the cysts are infectious when passed in the stool or shortly afterward,person to person transmission is possible.while animal are infected with Giardia,their importance as a reservoir is unclear.

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Giardia Lamblia

Diagnosis diagnosis by examining stool samples under a microscope. Common microscopical techniques include:  Trophs in diarrheic feces ; cyst in formed feces  At least 3 exams (one every other day) before judge negative  ELISA teats :detect soluble antigen  wet mount with iodine Several stool samples are usually needed on different days because cysts and trophozoites are not always present in the feces. Trophozoites can also be found from duodenal fluid or from biopsies taken during endoscopy

Trophozoite

Cyst

TrophozoiteCyst

Giardia lamblia Diagnosis

Epidemiology It has worldwide distribution.it is the most common frequent protozoan intestinal disease in the US and the most common identified cause of water-borne disease associated with breakdown of water purification system, travel to endemic area (Russia, India, and and middle east, etc. ) including  Poor sanitation  Travel to endemic area  Reduced immunity –malnutrition  Institutions example :children in nurseries and their caters World wide prevalence it occur at any age but is common in young children (estimated around 20% prevalence in young children in developing countries )

Common giardia lamblia symptoms include  bloating  Bad breath  Diarrhea or greasy floating stool  Fatigue  Loss of appetite  Nausea with or without vomiting  Stomach ache (abdominal pain)  Weakness  Weight loss

pathogenesis  Irritation and low grade inflammation of the duodenal or jejunal mucosa  Chronic or acute diarrhea associated crypt hypertrophy villous atrophy  Epithelial cell damage  Stools may be watery, semi solid, greasy, bulky and foul smelling

Transmassion  Contamination water drinking containing giardia cysts  Ingested food  Direct fecal contamination  Animals giardia harbored by rodents, cattle, sheep

Prevention  Do not drink water without boiling  Do not brush teeth with tap water  Do not eat uncooked or unpeeled fruit or vegetabile  Wash hands before eating food

Treatment  Giardiasis treatment is accomplished with antimicrobial drugs such as: metronidazole, nitazoxanide (good for treating children), tinidazole, paromomycin, quinacrine and furazolidone.  Treatment: Metronidazole OR Tinidazole Recently Albendazole.

Refrence  Medical microbiology  Medical parasitology  Giardia lamblia wikipedia, the free encoclopedia

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