Parasite Lab 2 PDF

Lab 2 - General stool examination Faecal specimens are examined for the presence of protozoa and helminthes larvae or egg. The stage of protozoa found in stools are (Trophozoites and cysts). The stages of helminthes usually found in stools are( eggs and larvae). COMPOSITION ¾ water, ¼ solid. Un...

Lab 2 - General stool examination Faecal specimens are examined for the presence of protozoa and helminthes larvae or egg. The stage of protozoa found in stools are (Trophozoites and cysts). The stages of helminthes usually found in stools are( eggs and larvae). COMPOSITION ¾ water, ¼ solid. Undigested and unabsorbed food Intestinal secretions, mucous Bile pigments and salts Decomposed products Bacteria and inorganic material Epithelial cells, leukocytes. PRECAUTION BEFORE COLLECTION Patient should avoid the following things for at least 48 hours before collection of stool: Mineral oils, bismuth, non absorbable anti diarrhoeal drugs, antimalarial drugs, antibiotics, etc , barium swallow examination before stool R/E Avoid iron containing drugs, meat, fish etc for atleast 48 hours before stool for occult blood. In constipated patients use only non residual purgative Stool examination Collection of faecal specimens 1-Give the patient the following: -A plastic cup or box with a light –fitting , lid. 2-Tell the patient to pass the stool specimens directly into the container, 3-The container with specimen should be labeled clearly with the following information: -Patients name or number. -Date of collection. -Time the patient passed the stool (ask the patient when he\she passed the stool) 5-The stool specimen must be large enough for satisfactory examination. The smallest quantity that should be accepted is about the size of a pigeons egg. Abnormal color of stool Black color: indicate iron medication (for treatment of anemia ) or upper GIT bleeding (due to peptic ulcer, stomach carcinoma or esophageal varices). Bright red color (Hematochezia): indicate lower GIT bleeding (due to piles and anal fissure). Clay color (gray-white): indicate obstructive jaundice Pale brown or pale yellow color: with a greasy consistency indicate malabsorption of fat (often with offensive odor). Yellow-green color: occurs in the stool of breast-fed infants who lack normal intestinal flora. Red brown color: indicate drugs as Tetracyclines, and Rifambicin antibiotics Reaction Normal is neutral Ph varies from 6.9 to 7.2 pH is dependent on bacterial fermentation and putrefaction in the bowel. Alkaline – excess protein ingestion Acidic – excess carbohydrate ingestion Consistency The consistency can be described as: -Formed -Soft -Loose -Liquid (watery) -Blood and mucus: Found blood in large amount is suggestive of bleeding piles or contamination with menstrual blood. Occasionally it may be due to the destruction of a blood vessel by an ulcerative process. Blood may be present in certain medical conditions like colitis, schistosomiasis. More rarely this may be the result of uremia or cancer. Occult blood Detect blood which is present in amount or from not visible macroscopically Normally nil Abnormal presence in condition of occult haemorrhage in the Gl tract. Microscopic examination Clinical significance of the test: Many pathogenic parasites are excreted in stool. Often when a person is infected with intestinal parasites, other symptom such as anemia, eosinophilia , diarrhea and malabsorption are also present. However diagnosis by physical examination is not sufficient to identify intestinal parasitic infection. Stool examination is essential to identify parasites that cause the disease. -Lugol's iodine How to prepare Lugol's iodine : Mix the 2 GM potassium iodide with about 200 ml of water until it is completely dissolved. Add the 1 gm of iodine to the potassium iodide solution, Procedure: 1- Label a glass slide with the patient name and or lab number. 2-Put one drop of normal saline in the middle of the left of the slide. 3-Put one drop of Lugol's iodine in the middle of the right half of the slide. 4-Take a small piece again and mix it with the drop of Lugol's iodine on the right half of the slide. 5-For the saline preparation use the 10X objective and 40X objective. Usually reported as the number seen in the entire preparation as follows. Scanty (rare)n1-3, 3-10(+) 10 to 20 (++) , 20 to 40(+++), and more than 40(++++). Cells are usually reported as the number seen per high power field( HPF). Buffered methylene blue (BMB) mount ( to be prepared if amoebic Trophozoites are seen in the saline mount) used to stain amoebic trophozoite only Report for general stool examination. (G. S.E) 1-Macroscopic examination. Color : brown, yellow, green, black, …. Consistency : formed , loose, soft, watery, … Blood or mucus Occult blood PH: Others Adult worm Larvae Segments 2-Microscopic examination. Pus RBC Parasites Yeast