MIDTERMS: Kato-Katz

Question 1

It was developed in____ by the Japanese physician,______ (1913-2011), together with his adviser,______ (1891-1989)

Answer 1

1954

Dr. Katsuya Kato

Dr. Momoshige Miura

Question 2

The technique was modified for use in field studies in_____ by a Brazilian team of researchers led by the Brazilian Parasitologist,______ (1940)

Answer 2

1972

Naftale Katz

Question 3

Kato-Katz from the names..

Answer 3

Katsuya Kato
Naftale Katz

Question 4

Advantages

Answer 4

Kato-Katz technique is used for qualitative and quantitative diagnosis of intestinal helminthic infestations; caused by Ascaris lumbricoides, Trichuris trichiura, hookworm, and especially Schistosoma spp.

Uses larger amount of stool

Qualitative & Quantitative

Mass screening purposes (WHO)

High sensitivity

Question 5

Disadvantages

Answer 5

Can be used for formed stool only

Protozoan cysts and trophozoites can not be seen using this technique

Inter and intra - specimen variation of egg output

Lacks sensitivity for the diagnosis of low intensity infections

Question 6

In the Kato-Katz technique, feces are pressed through a_____ to remove large particles/debris.

Answer 6

mesh screen

Question 7

A portion of sieved sample is then transferred to the hole of a ______ on a slide.

Answer 7

Template

Question 8

After filling the hole, the template is removed and the remaining sample is covered with a piece of ______ soaked in______.

Answer 8

cellophane

glycerol

Question 9

The_____ clears the fecal material from around the eggs.

The eggs are then counted and the number calculated_____ of feces.

Answer 9

glycerol

per gram

Question 10

Kato-set

Answer 10

Template with hole
screen, nylon or plastic
plastic spatula

Question 11

Cellophane as cover slip, soaked in ______ or ______

Answer 11

glycerol-malachite green or glycerol-methylene blue solution.

Question 12

Pre-analytical

Specimen:

Fresh stools collected within _______ after passage

Answer 12

30 minutes to 1 hour

Question 13

Criteria for rejection:

Answer 13

Formed stool greater than 24 hours after passage before processing or preservation

Stool specimen less than a thumb size if formed

Watery stools cannot be used

Question 14

The screen stainless steel, nylon or plastic should have a hole size of_____

Answer 14

60 - 105 um.

Question 15

50% Glycerol Solution

Answer 15

100mL Distilled Water + 100mL Glycerine

Question 16

3% Malachite Green

Answer 16

3% 1mL of MG or MB + 200mL Glycerol Solution

Question 17

Templates used:

Answer 17

9 mm hole 1 mm thickness = 50mg

6 mm hole x 1.5 mm thickness = 41.7mg

6.5 mm hole x 0.5 mm thickness = 20mg

Question 18

9 mm hole 1 mm thickness = ____

Answer 18

50mg

Question 19

6 mm hole x 1.5 mm thickness =____

Answer 19

41.7mg

Question 20

6.5 mm hole x 0.5 mm thickness =____

Answer 20

20mg

Question 21

Specification of the plastic templates included in the Kato-Katz kits provided by

Answer 21

Vestergaard Frandsen

Chinese Center for Disease Control and Prevention (China CDC)

Question 22

Analytical - Procedure

1. Label a glass slide with the sample_____
2. Place a small amount of the fecal sample on a newspaper and press a piece of_____ on top.
   Using a spatula, scrape the sieved fecal material through the screen so that only the debris remains.

Answer 22

number/name

nylon screen

Question 23

Analytical phase

3. Scrape up some of the sieved feces to fill the hole in the_____, avoiding air bubbles and leveling the feces off to remove any excess.
4. Carefully lift off the template and place it in a bucket of water mixed with______ so that it can be reused.

Answer 23

template

concentrated detergent

Question 24

Analytical phase

5. Place one piece of the cellophane, which has been soaked overnight in_________ solution, over the fecal sample.
6. Place a clean slide over the top and press it evenly downwards to spread the feces in a circle. Carefully remove the slide by gently sliding it sideways to avoid separating the cellophane strip. If done well, it should be possible to read newspaper print through the stool smear. Place the slide with the cellophane upwards.

Answer 24

methylene blue glycerol

Question 25

Examination & Results Place the slide under a microscope and examine the whole area in a__________ pattern.

Answer 25

systematic zigzag

Question 26

Examination & Results Record _____ and _____ of each egg of each species on a recording form alongside the sample number. Finally, multiply the number of eggs by the appropriate number (see inlet-information of the kato-set) to give the number of________- the standard measurement to assess the intensity of infection.

Answer 26

type and number eggs per gram (epg)

Question 27

If hookworm is present in the area the slide should be read within_______ After that time, the hookworm eggs disappear.

Answer 27

30-60 minutes.

Question 28

Post-Analytical/Reporting Uses_____ in proportion to the amount of stool examined.

Answer 28

template

Question 29

Post-Analytical/Reporting Templates = Factor (To be used to compute for EPG) 50 mg = 41.7 mg = 20 mg =

Answer 29

20 24 (commonly used) 50

Question 30

(To be used to compute for EPG)

Answer 30

Factor

Question 31

Reporting criteria Formula for epg

Answer 31

# of ova per species x template factor = # of eggs per gram (EPG) of stool

Question 32

Example: You counted 951 A. lumbricoides ova in the whole Kato-Katz slide using the 20mg template. So it will be…

Answer 32

951 x 50 = 47,550 eggs per gram stool.

Question 33

Kato-Katz or Kato Thick-Smear technique for feces is satisfactory for detecting

Answer 33

medium and large helminth eggs in feces

Question 34

Kato-Katz or Kato Thick-Smear technique for feces not good for

Answer 34

small trematode eggs

Question 35

Kato-Katz or Kato Thick-Smear technique for feces Its chief advantage is that a _______ of feces can be placed on the slide than the usual direct wet mount.

Answer 35

larger quantity

Question 36

may collapse and disappear shortly after clearing, and unless preparations are examined as soon as the fecal film has cleared, _____ infections may be missed.

Answer 36

Hookworm eggs

Question 37

This technique is of little value or no value in detecting____ infections.

Answer 37

protozoa

Question 38

Hydrophilic cellophane - _____thick strips______ or ______ in size

Answer 38

40-50 um thick ***25 x 30*** or ***25 x 35 mm***

Question 39

Glycerol-malachite green or glycerol-methylene blue solution ______of 3% aqueous malachite green or 3% methylene blue is added to____ of distilled water and mixed well.

Answer 39

1 ml 100 ml

Question 40

To speed up clearing and examination, the slide can be placed in a_______ incubator or kept in______ for several minutes.

Answer 40

40°C direct sunlight

Question 41

…will remain visible and recognizable for many months in these preparations. …clear rapidly and will no longer be visible after 30-60 minutes. …may be recognizable for up to several months but it is preferable in a schistosomiasis endemic area to examine the slide preparations within 24. hours.

Answer 41

Ascaris and Trichuris eggs Hookworm eggs Schistosome eggs

Question 42

With high egg counts, to maintain a rigorous approach while reducing reading time, the ____________ with 0.1 mol/liter NaOH may be recommended (Basic Laboratory Methods in Medical Parasitology, WHO, 1991).

Answer 42

Stoll quantitative dilution technique

Question 43

is a clearing solution

Answer 43

Glycerine

Question 44

Purpose of malachite green is to

Answer 44

give color to the cellophane in order to give a pale green background to the eggs to minimize the brightness of the microscopic field

Question 45

If malachite green is not available, green ________ may be used.

Answer 45

cellophane soaked in glycerine

Question 46

The preparation is best examined within…

Answer 46

10 to 20 minutes

Question 47

It is very good in detecting eggs with thick shells… but not eggs with thin shells…

Answer 47

(e.g., Ascaris and Trichuris) (e.g., hookworm).

Question 48

In many instances, if the preparation is kept too long before examination, ________ become too transparent or distorted, making identification very difficult.

Answer 48

hookworm eggs

Question 49

Usefulness is limited if stools are ______. Likewise, it is not able to detect_____ and _____

Answer 49

diarrheic or watery protozoan cysts and trophozoites

Question 50

…is the main determinant for the sensitivity of this technique, since well-formed stools yield higher egg counts than moist ones.

Answer 50

Consistency of the stool

Question 51

For the identification of Schistosoma ova,_________ can be layered over the cellophane paper. This method can help in the visualization of the_____.

Answer 51

1% eosin solution miracidium

Question 52

Percentage of glycerol sol

Answer 52

50%

Question 53

Percentage of malachite green

Answer 53

3%

Question 54

Most commonly used factor

Answer 54

24