II. Specimen Collection, Transport And Processing

Question 1

Drugs that can interfere with the diagnosis

Answer 1

• antidiarrheals
• antacids
• bismuth
• barium
• laxatives

Question 2

How much sample is needs for formed stool

Answer 2

2-5 grams (walnut/thumb size)

Question 3

How much sample do you need for watery stool sample

Answer 3

5-6 spoons

Question 4

Proper labeling of specimen should include

Answer 4

• patients name
• patient ID
• age
• sex
• date and time of collection

Question 5

General considerations

Answer 5

1) number and type of specimen

2) time factor in examination

Question 6

Passed on continual basis

Answer 6

Helminth eggs

Question 7

Passed intermittently multiple specimen collected at 2-3 days interval

Answer 7

Protozoans

Question 8

Should be examined within 30 minutes because it contain trophozoites which are fragile.

Answer 8

Watery sample

Question 9

Should be examined > 1 hr, or within the day

Answer 9

Formed specimen

Question 10

Collection of specimen

Answer 10

1) use a clean, watertight container with a tight-fitting lid
2) bring sample immediately to the laboratory

Question 11

Things that you should NEVER do in specimen collection

Answer 11

Never:
• leave the specimens exposed to the air container without lids
• accept specimens mixed with urine or water
• examine specimen without proper PPEs

Question 12

Thing that you should ALWAYS remember in specimen collection

Answer 12

Always:

• prioritize examination of liquid stools especially those containing mucus or blood

Question 13

It preserves the morphology

Answer 13

Fixatives of preservation

Question 14

What is the recommended ratio of fixative to stool

Answer 14

3 fixative : 1 stool (3:1)

Question 15

5 Fixative of preservation

Answer 15

• formalin
• polyvinyl alcohol (PVA)
• sodium acetate formalin (SAF)
• modified PVA
• single vial system

Question 16

Always or never: Freeze the stool sample

Answer 16

NEVER

Question 17

1) a fixative that can destroy the trophozoites
2) an all purpose fixative
3) may be routinely
4) used for direct examination & concentration procedure but not for permanent stain

Answer 17

Formalin

Question 18

What is the concentration of formalin for the protozoan cyst

Answer 18

5%

Question 19

What is the concentration of formalin for the trophozoites

Answer 19

10%

Question 20

2 advantages of formalin

Answer 20

• easy to prepare

* preserves the specimen

Question 21

1) a permanent staining

2) contains Mercuric chloride

Answer 21

Schaudinn’s solution

Question 22

A fixative that is very toxic

Answer 22

Mercuric chloride

Question 23

It is amalgamate substance that is found in the thermometers

Answer 23

Mercury

Question 24

1) acts as an adhesive for the stool specimen when preparing slides for staining
2) combined with Schaudinn’s fixative

Answer 24

Polyvinyl alcohol (PVA)

Question 25

1) advantage of polyvinyl alcohol | 2) disadvantage of PVA

Answer 25

1) used for permanent staining | 2) it contains mercuric chloride

Question 26

A fixative that is used as an alternative to PVA-Shaudinn's

Answer 26

Sodium acetate formalin (SAF)

Question 27

1) advantages of SAF | 2) disadvantages of SAF

Answer 27

1) easy to prepare, long shelf life | 2) adherence are not good, Protozoans morphology is not clear

Question 28

1) another alternative to Mercury based PVA | 2) contains copper sulfate or zinc sulfate

Answer 28

Modified polyvinyl alcohol

Question 29

1) advantage of MPA | 2) disadvantage of MPA

Answer 29

1) can be used for concentration and staining methods | 2) bad quality of fixing

Question 30

1) useful for fixation of parasite | 2) staining of preserved stool in MIF yields unsatisfactory result

Answer 30

Merthiolate-Iodine-Formalin (MIF) | *formalin is the preservative

Question 31

2 processes or examination of specimen

Answer 31

* macroscopic examination of specimen | * microscopic examination of specimen

Question 32

What are being tested in the macroscopic examination

Answer 32

Color | Consistency

Question 33

Stool according to color

Answer 33

Black Yellow Brown Green

Question 34

Stool according to consistency

Answer 34

Formed Watery Smooth

Question 35

1) an examination to identify the parasite 2) to detect motile trophozoites 3) to detect larva, eggs and cyst present 4) to detect erythrocytes, pus cells, fat globules and Charcot Leyden Crystals

Answer 35

Microscopic examination of specimen

Question 36

Product of eosinophil degradation

Answer 36

Charcot Leyden crystal

Question 37

2 common lab procedures for stool analysis

Answer 37

Direct fecal smear | Kato thick smeat

Question 38

Simplest screening procedure for intestinal parasite

Answer 38

Direct fecal smear

Question 39

How many percent does it need for the NaCl/NSS in direct fecal smear

Answer 39

0.85%

Question 40

Used to detect live motile trophozoites

Answer 40

NSS

Question 41

1) used to easily visualize the structure 2) acts as stain 3) oldest stain 4) low sensitivity

Answer 41

Lugol's iodine

Question 42

How many mg is used in every lab procedure of stool

Answer 42

2 mg of stool

Question 43

True or False: For proper collection and handling of specimen there should be no contamination

Answer 43

True