A patient present with diarrhoea. Analysis of stool on wet mount shows mobile protozoa without RBCs and pus cells. The diagnosis is:
Ans. (b) Giardiasis a. Balantidium coli Live in large intestine causing balantidiasis (zoonosis). Occurs in 2 stages; trophozoite (binucleated) and cyst (= infective form). Clinical disease results only when trophozoites burrow into mucosa causing ulcer and submucosal abscesses resembling lesion of amoebiasis so it 'resembles amoebiasis' causing diarrhoea or frank dysentery, so stool may contains pus cells. Treatment: Tetracyline/metronidazole/nitroimidazole b. Giardia lamblia Intestinal flagellate, the only protozoan parasite found in the lumen of human small intestine (Duodenum and upper jejunum). Infection is acquired by ingestion of cysts in contaminated food and water. It does not invade tissue (so no RBC and pus cells in faeces) but remains attached to epithelial surface by sucking disc which may cause abnormalities of villous architecture and loss of brush border enzymic activities leading to self limited mucus diarrhoea; malabsorption like syndrome; weight loss; abdominal cramps. Occasionally cause biliary colic and jaundice. Piiinkci- p 36 Diagnosis: Detection of cysts (encystation occur in colon) as well as trophozoite (die outside so hot infectious) in stool sample or in duodenal aspiration by enterotest if biliary symptoms predominate. Detection of antigen by ELISA or immunochromatographic strip test. Giardiasis is a cause of traveller's diarrhoea. Treatment: DOC - Metronidazole/tinidazole Alternative - quinacrine hydrochloride and furazolidone. c. Trichomonas vaginalis Not cause diarrhoea. d. Entamoeba histolytica It cause amoebic dysentery so stool contain cellular exudate as well as RBC, charcot leyden crystals, amoeba, etc.
Balantidium Coli
Giardiasis
Trichomonas hominis
Entamoeba histolytica