Giardia Ppt M.sc Medical 4th Sem

Giardia lamblia

PRESENTED BY : Sonica RANI M.Sc. MEDICAL MICROBIOLOGY (4ᵗʰ SEMESTER)

GIARDIA Giardia is a microscopic parasite that causes the diarrheal illness known as giardiasis. Giardia commonly nick named as Grand old man of the intestine. Giardia lamblia of small intestine (deudenum) of men possess a bilateral symmetrical body.

HISTORICAL BACKGROUND • Giardia intestinalis was first observed by Anton van Leeuwenhoek (1681) - A Dutch tradesman in his own stool and he described them as animalcules. • He is also called the "father of Microbiology”.

SYSTEMATIC POSITION Phylum Sub phylum Class Order Genus Species

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Protozoa Plasmodroma Mastigophora Diplomonadida Giardia Intestinilis or lamblia

GEOGRAPHICAL DISTRIBUTION World wide

HABITAT Deudenum and the upper part of jejunum of man. MORPHOLOGY EXISTING TWO PHASES :• Trophozoite • Cyst

LIFE CYCLE OF GIARDIA LAMBLIA • Infection occurs by the ingestion of cysts in contaminated water, food, or by the fecal-oral route (hands or fomites).

• In the small intestine, excystation releases trophozoites (each cyst produces 2 trophozoites). • Trophozoites multiply by longitudinal binary fission remaining 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 as the parasites transit toward the colon.

• Both cysts and trophozoites can be found in the feces. • The cyst is the stage found most commonly in non-diarrheal feces (The cysts are hardy, can survive several months in cold water). • Trophozoitess are found in the diarrheal stools.

LIFE CYCLE OF GIARDIA LAMBLIA

TRANSMISSION Giardia is transmitted via the fecal oral route with the ingestion of cyst. Primary roots are personal contact and contaminated water and food. The cyst can stay infectious for up to 3 months in cold water.

PATHOGENECITY • With the help of sucking this parasite .The parasite attaches itself on to the convex surface of the epithelial cell in the intestine and may cause a disturbance of intestinal function leading to malabsorption of fat. • The patient may complain of looseness of bowel and mild steatorrhea. The parasite is also capable of producing by its toxic effect.

SYMPTOMS Symptoms include: • Diarrhoea • Loose or watery stool • Foul-smelling stool • Stomach cramps • Upset stomach • Weight loss • Dehydration Some may be asymptomatic.

LABORATORY DIAGNOSIS • Stool examination: - Macroscopic examination - Microscopic examination

• Enterotest (string test) • Serological test: ELISA • Molecular diagnosis: DNA probe, PCR

TREATMENT • The most common treatment for giardiasis is metronidazole for 5-10 days. It eradicates the Giardia more than 85 % of the time. • Furoxone for 7-10 days. • Quinacrine is very effective for treating giardiasis. • Combination therapy also may be effective (e.g., quinacrine and metronidazole).

PREVENTION • • • •

Avoid water and food that might be contaminated. Boil water before drinking. Do not brush teeth with tap water that may be contaminated. Wash hands before eating food.

REFERENCES • Chatterjee K.D; Parasitology (Protozology and Helmithology) 13rd Edition.2012, CBC Publisher. pp - 37-40. • Ghosh S, Chander J; Paniker’s Textbook of Medical Parsitology 8th Edition 2018, The Health Science Publisher New Delhi. pp - 32-40.