Parasitology Laboratory Quiz1

Question 1

Most common procedure performed in the area of Parasitology

Answer 1

Examination of a stool specimen for ova and parasites

Question 2

Typical stool collection protocol

Answer 2

3 specimens

Question 3

Up to 6 specimens in 14 days

Answer 3

For amebiasis

Question 4

Stool sample from patients whose therapy includes?

Answer 4

Barium, Bismuth, or mineral oil

Question 5

Patient’s whosever in therapy should be collected prior to the therapy or not until?

Answer 5

5 to 7 days after the completions of therapy

Question 6

For patient’s who have taken antibiotics or antimalarial medication should be delayed for how many weeks?

Answer 6

2 weeks following therapy

Question 7

Containers for stool collection

Answer 7

Clean, watertight container with a tight-fitting lid

Question 8

Acceptable amount of stool

Answer 8

2 to 5 g ( often referred to as the size of walnut

Question 9

According to blank thumb-sized specimen of formed stool 5 to 6 tablespoon of watery stool

Answer 9

Belizario et al

Question 10

Temporary storage of fecal samples in a refrigerator

Answer 10

3-5 degree celcious is acceptable

Question 11

Are killed by refrigeration

Answer 11

Trophozoites

Question 12

Are usually damage

Answer 12

Helminth eggs and protozoan cysts

Question 13

NEVER

Answer 13

Freeze stool samples
Keep them in incubations

Question 14

Should not be allowed to be contaminate the stool specimen

Answer 14

Urine

Question 15

Stool should not be blank from toilet bowl water

Answer 15

Not be retrieved

Question 16

Used to demonstrate the motility of protozoan trophozoites

Answer 16

Fresh specimens

Question 17

Should be examined within 30 minutes of passage

Answer 17

Liquid stool

Question 18

Should be evaluated within 1hour of passage

Answer 18

Semi formed specimen’s

Question 19

Can be held for 24 hours

Answer 19

Formed stool specimens

Question 20

Substance that preserve the morphology of protozoa and prevent further development of certain helminth eggs and larvae

Answer 20

Fixatives

Question 21

5% ideally preserves protozoan cyts
10% preserve’s helminths eggs and larvae

Answer 21

Formalin

Question 22

Adhesive for the stool when preparing slides for staining
Most often combined with schaudinn solutions

Answer 22

Polyvinyl Alcohol (PVA)

Question 23

Schaudinn Solutions contains?

Answer 23

Zinc sulfate, copper sulfate or mercuric chloride as a base)

Question 24

Can be used for performing concentration techniques and permanent stained smears
It is a liquid fixative with long-shell life

Answer 24

Sodium acetate formalin

Question 25

Other alternatives to mercury- based PVA are the use of substitutes compounds contain copper sulfate or zinc sulfate

Answer 25

Modified polyvinyl alcohol

Question 26

Free of formalin and mercury and can be used for concentration techniques and permanent stained smears alter

Answer 26

Alternative single vial system’s

Question 27

contains merthiolate (also called thimerosal) and iodine which act as staining components, while
formalin acts as the preservative

Answer 27

MERTHIOLATE-IODINE-FORMALIN

Question 28

Determine: color and consistency

Answer 28

MACROSCOPIC EXAMINATION

Question 29

Consistency or degree of moisture in a stool: can be classified as:

Answer 29

Formed
Semi-formed
Soft
Loose
Watery

Question 30

Liquid stool

Answer 30

(+) protozoan trophozoites

Question 31

Fully formed stools

Answer 31

(+) protozoan cysts

Question 32

Liquid or formed stools

Answer 32

(+) Helminth eggs and larvae

Question 33

color of the normal stool

Answer 33

Brown

Question 34

Unusual colors of stools

Answer 34

purple, red or blue

Question 35

should always be reported.

Answer 35

Presence of blood

Question 36

responsible for the brown color of the stool

Answer 36

Stercobilin

Question 37

suggests UPPER GIT Bleeding- esophagus, stomach and duodenum

Answer 37

Dark-colored blood

Question 38

means LOWER GIT Bleeding 􏰁 ileum, jejunum, large intestine

Answer 38

Bright red blood

Question 39

found in stool include adult worms, proglottids, pus & mucus

Answer 39

Gross Abnormalities

Question 40

should be examined for parasites such as pinworms, tapeworm proglottids, and adult
worms

Answer 40

Surface of the stool

Question 41

may suggest presence of amebic ulcerations in the large intestine

Answer 41

Blood and/or mucus in loose/liquid stool

Question 42

usually associated with irritation & bleeding

Answer 42

Bright red blood on the surface of a formed stool

Question 43

3 DISTINCT PROCEDURES: should be performed on a fresh specimen

Answer 43

1. Direct Wet Preparations
2. Concentrated Technique resulting in concentrated wet preparations
3. Permanently stained smear

Question 44

Main purpose: To detect the presence of motile protozoan trophozoites
o made by placing a drop of 0.85% saline on a glass slide (a 3- × 2-inch size is suggested) and mixing with a
small portion of unfixed stool using a wooden applicator stick or another mixing tool

Answer 44

DIRECT SALINE WET PREPARATION

Question 45

Small portion of unfixed stool

Answer 45

About 2 mg of stool

Question 46

is placed on the slide and the preparation is examined microscopically in a
systematic fashion.

Answer 46

22-mm square cover slip

Question 47

should be scanned using the low power (10×) objective on the microscope,
and the power should only be increased when a suspicious object requires further investigation.

Answer 47

entire cover glass

Question 48

kills the trophozoites present in a stool specimen.

Answer 48

Iodine

Question 49

is placed over a glass slide and covered with cut
cellophane paper soaked in a mixture of glycerine and malachite green solution

Answer 49

50 to 60 mg of stool

Question 50

is a clearing solution and malachite green is used to give color to the cellophane in order to give a pale green background to the eggs and to minimize the brightness of the microscopic field.

Answer 50

Glycerine