UNIT 3 DIAGNOSTIC PARASITOLOGY Flashcards
TRUE OR FALSE
Motility of trophozoites is best demonstrated using Lugol’s Iodine
FALSE (Lugol’s Iodine is used to determine the parasitic structure)
TRUE OR FALSE
Improper placement of coverslip often leads to the formation of air bubbles in the fecal smear
TRUE
What reagent acts as a clearing agent in the Kato-Katz preparation?
Glycerol, Glycerine solution
What is considered as the golden standard for the diagnosis of malaria?
Thin & Thick blood smear
What is the specimen of choice for the diagnosis of pinworm infections?
Cellophane swab/ Scotch-tape specimen
How many grams of basic fuchsin are needed to dissolve in the liquefied phenol?
1 gram
5% formalin consist of ___ ml of formaldehyde and ____ ml of distilled water or saline
50 ml; 950 ml
Lugol’’s solution is a direct part in what type of diagnostic test?
Direct Fecal Smear
NSS or Normal Saline Solution contains what percent of NaCl?
0.85% NaCl
Simplest and easiest technique to facilitate detection of intestinal parasites that infected subjects pass in their feces
Direct Fecal Smear
Small amount of fresh feces is mixed with either saline to _________ or lugol’s iodine to ________
detect protozoan motility; reveal the parasite structure
When examining diarrheic or liquid feces containing mucus, both preparations should be applied to what part of the stool sample?
mucous part
Diagnostic test used to monitor large-scale treatment programs implemented for the control of soil-transmitted helminth infections because of its simple format and ease of use in the field.
It quantifies eggs and establishes the burden of intestinal infection
Kato-Katz Technique
Manner of reporting of previous technique
Eggs per gram stool (epg)
TRUE OR FALSE
To speed up clearing and examination, the slide can be placed in a 40 degree celsius incubator or kept in direct sunlight for several minutes.
TRUE
TRUE OR FALSE
A. lumbricoiodes, T trichiura, and hookworm eggs will remain visible and recognizable for many months.
FALSE (hookworm eggs clear rapidly and will no longer be visible after 30-60 minutes)
For all except Schistosome eggs, keep the slide for one or more hours at room temperature to clear the fecal material prior to examination under the microscope.
FALSE (should be HOOKWORM EGGS not Schistosome eggs)
TRUE OR FALSE
Schistosome eggs may be recognizable for up to several months but it is preferable to examine the slide preparations within 24 hours.
TRUE
In using the kato-katz technique, the smear should be examined systematically where multiplying the appropriate factor to give the no. of epg of feces. What are the factors to be used if you are using:
- ) 50 mg template
- ) 20 mg template
- ) 41.7 mg template
20; 50; 24
This solution provides an isotonic environment when your are observing the stool for DFS analysis
Normal Saline Solution
Stain used in Direct Fecal Smear to show the trophozoites
Nair’s Methylene Blue
Why is it important to use the right amount of stool in the Direct Fecal Smear preparations?
if the stool sample is more concentrated, the components inside the stool will be difficult to identify and differentiate from each other
When placing the coverslip on the samples in a Direct Fecal Smear, what action will make the stool sample spread out?
Capillary Action
TRUE OR FALSE
The use of a cover slip will slow down the process of drying and prevent the drying process.
FALSE (it can only slow down the process of drying)
TRUE OR FALSE
In the Kato-Katz technique, the consistency of the stool is the main determinant for the sensitivity of this technique and it can only be done on freshly formed stool and not on liquid and preserved samples.
TRUE
Another type of test similar to kato-katz in which it is used to quantify parasites especially in helminth infections
McMaster
This is used as the clearing agent as well as to maintain the color of the mixture in the kato-katz technique
glycerol-malachite green
When examining a sample where the kato-katz technique has been used under the microscope, what objective should you use to observe the specimen?
Low Power objective
TRUE OR FALSE
in blood smears, the Thick smear is used to identify malarial parasites while the Thin smear is used in the rapid diagnosis of malarial infection
FALSE (Thin is used for identification of parasites while Thick is used for diagnosis)
This stain used in blood staining:
the red cells stain pale red
white cell nuclei stain purple
eosinophils stain bright purple red
neutrophils stain deep pink purple
Giemsa Stain
This stain used in blood staining:
light red erythrocytes
bright blue leukocyte nuclei
bright red eosinophilic granules
pink neutrophilic granules.
Wright’s Stain
TRUE OR FALSE
in wright’s stain, it does not need to undergo fixation because it contains alcohol
TRUE
The best type of specimen to be used in a blood smear.
non-additive blood sample
The difference between the Giemsa Stain and Wright’s Stain
their pH, Giemsa is more basic
TRUE OR FALSE
Thick blood film that will be stored for an extended period prior to staining should be dehemonoglobized and then thoroughly dried.
TRUE
What component in the Giemsa stain provides a better staining of the malarial parasite?
Azure B
TRUE OR FALSE
After making the thin and thick smears, both are fixed with 100% absolute methanol.
FALSE (only the THIN smear is fixed with methanol)
