Kato Thick Smear and Kato Katz Technique

Question 1

Also known as cellophane thick smear

Answer 1

Kato Thick smear

Question 2

Kato Thick smear is useful in field surveys for

Answer 2

helminth infections

Question 3

Useful in field surveys for helminth infections thick shells such as

Answer 3

Ascan’s and Trichuris

Question 4

Kato thick smear is not ideal for

Answer 4

Heminth larvae or protozoa

Question 5

Uses glycerine and malachite green

Answer 5

Kato thick

Question 6

It dissolve fecal materials

Answer 6

Glycerine

Question 7

Protect eye from the brightness of the microscope light

Answer 7

Malachite green

Question 8

Materials needed for kato thick

Answer 8

Microscope
Human stool sample (soft-formed consistency)
Clean glass slides
Applicator stick
Marking pens
Rubber stopper (no. 4 or 5)
Scrap paper/news paper/paper towel
Pre-treated cellophane cut into 1”X 1”

Question 9

Preparation of the Pre-treated Cellophane

Answer 9

Cellophane are soaked in glycerine-malachite green solution:
Glycerine 500 ml
3% Malachite Green solution 5 ml
Distilled water 500 ml

Question 10

may be used and the malachite green omitted from the preparation. The same green background is produced.

Answer 10

Green cellophane

Question 11

Procedure for Kato Thick:

Answer 11

1. Label slide properly and place approximately 50-60 mg of stool (mongo/soy bean size) at the center of a glass slide and cover with a square piece of pretreated cellophane. Arrange the cellophane using a forcep.
2. With the aid of a rubber stopper (no. 4 or 5), press the cellophane gently to spread the stool specimen evenly to about the circumference of the stopper. Make sure that the specimen will not spread beyond the cellophane cover
3. Leave the prepared slide at room temperature for 10-20 minutes. During this time, the microscopic field becomes clear due to the action of glycerine on stool sample
4. Examine the preparation under the microscope after standing and look for helminth eggs/ova under LPO. Shift to HPO for identification of parasite.

Question 12

In kato thick:

Don’t allow the slides to stand for long period (more than an hour) as it ____________________ in glycerine solution

Answer 12

causes drying and shells of hookworm will dissolve

Question 13

Eggs that are usually recovered in Kato Thick (SHAT)

Answer 13

Schistosoma
Hookworm
Ascaris
Trichuris

Question 14

Manner of reporting for Kato Thick (if present)

Answer 14

Number of eggs of parasite name per smear or in plusses

Question 15

Manner of reporting for Kato Thick if negative

Answer 15

no ova seen

Question 16

Manner of reporting for Kato Thick for multiple infection

Answer 16

separate reporting

Question 17

useful for assessing the intensity of infection in schistisomiasis and common soil - transmitted helminthiac is like ascariasis, trichuriasis, and hookworm infection

Answer 17

Kato- Katz method

Question 18

Materials needed for Kato Katz Method

Answer 18

Microscope
• Human stool sample (softformed consistency)
• Clean glass slides
• WBC counter
• Marking pens
• Rubber stopper (no. 4 or 5)
• Scrap paper/news paper/paper towel
• Pre-treated cellophane cut into 1”X 1”
• Scraper (plastic or wood)
• Wire net (105 mesh) or layer of gauze
• Template –plastic or cardboard (3x4 cm) with a 6 mm hole at the center

Question 19

Procedure for Kato katz

Answer 19

Label slide and position the template at the center of the slide.
2. Place the fecal sample on the cover of the stool container.
3. Sieve or strain the fecal sample with the wire net.
4. Scrape the feces which passed through the net then transfer them to the central hole of the card or plastic template lying over a clean glass slide.
5. Fill up the hole, flatten the top level and lift the card or the template leaving the fixed amount of feces on the slide.
6. Put the pre-treated cellophane over the fecal sample.
7. With the aid of a rubber stopper (no. 4 0r 5), press the cellophane gently to spread the stool specimen evenly to about the circumference of the stopper. Make sure that the specimen will not spread beyond the cellophane cover.
8. Leave the prepared slide at room temperature for 10-20 minutes. During this time, the microscopic field becomes clear due to the action of glycerine on stool sample.

Question 20

Eggs recovered in Kato Katz

Answer 20

Schistosoma spp.
Ascaris
Hookworm
Trichuris

Question 21

How to solve the number of eggs of parasite per gram of stool

Answer 21

= # of eggs of parasite counted X 1000 mg/g divided by 43 mg feces

Question 22

Light Intensity is 1 – 4,999 epg

Answer 22

Ascaris lumbricoides

Question 23

Moderate Intensity and 5,000 – 49,999 epg

Answer 23

Ascaris lumbricoides

Question 24

Heavy Intensity and ≥ 50,000 epg

Answer 24

Ascaris lumbricoides

Question 25

light intensity 1-999 epg

Answer 25

Trichuris trichiura

Question 26

1000 -9999 eps Moderate Intensity

Answer 26

Trichuris trichiura

Question 27

> 10,000 epg Heavy Intensity

Answer 27

Trichuris trichiura

Question 28

1 – 99 epg light Intensity

Answer 28

Schistosoma japonicum and Schistosoma mansoni

Question 29

100 – 399 epg Moderate Intensity

Answer 29

schistosoma japonicum and Schistosoma mansoni

Question 30

100 – 399 epg Moderate Intensity

Answer 30

schisto soma japonicum and Schistosoma mansoni

Question 31

≥400 epg Heavy intensity

Answer 31

Schistosoma japonicum and Schistosoma mansoni

Question 32

What is the Intensity Of Infection: 12 Ascaris eggs in the entire smear 279 Ascaris eggs per gram of stool

Answer 32

Light infection with Ascaris

Question 33

What is the Intensity of Infection: 5 Trichuris eggs in the entire smear 116 Trichuris eggs per gram of stool

Answer 33

Light infection with Trichuris

Question 34

For Kato Thick, Leave the prepared slide at

Answer 34

room temperature for 10-20 mins