Safety Precautions In Handling Biological Specimens

Question 1

Laboratorians working with stool specimens face potential risks including:

Answer 1

ingestion of eggs or cysts

skin penetration by infective larvae

infection by nonparasitic agents found in stool and biologic fluids

Question 2

risks can be minimized by adopting__________ as well as____________ (Biosafety Level ___)

Answer 2

universal precautions

standard microbiological laboratory practices

2

Question 3

Wear protective (3) when processing specimens.

Answer 3

safety glasses, gloves, and laboratory coat

Question 4

Use_______ as needed.

Answer 4

biological safety cabinets

Question 5

_________ work surface at least once a day and after spill of potentially infectious material.

Answer 5

Decontaminate

Question 6

If you have cuts or abrasions on the skin on your hands, cover them with

Answer 6

adhesive dressing

Question 7

_________ and ________ after completing any task involving the handling of fecal material.

Answer 7

Remove gloves and wash your hands

Question 8

T or F

stool specimens that have been fixed in preservatives because may still be infectious.

Answer 8

True

Question 9

fixation in_____ takes days or weeks to kill some parasite cysts or oocysts that are protected by a thick shell.

Answer 9

formalin

Question 10

Eggs of nematodes like:

may continue to develop into the infective stage even when preserved in formalin.

Answer 10

Ascaris lumbricoides
Trichuris trichiura
hookworm

Question 11

Follow universal precautions for the prevention of bloodborne pathogens when working with human serum and other body fluids. These include:

Answer 11

Wear personal protective equipment such as safety glasses, gloves, and laboratory coats.

If you have cuts or abrasions on the skin of your hands, cover them with adhesive dressing.

Use needles and lancets only once, and dispose of them in a “sharps” container for decontamination.

Remove gloves and wash your hands after completing any task involving the handling of biological material.

Question 12

is the most commonly used specimen in the diagnosis of parasitic infections.

However:
(5) may also be used for the demonstration of parasites’ diagnostic stages.

Answer 12

Stool specimen

blood, sputum, urine, other body fluids, and tissue biopsy

Question 13

The usual diagnostic stages of intestinal parasites are protozoan ____ and ____ and, helminth _____ and _____

Answer 13

trophozoites and cysts

eggs and larvae

Question 14

Since stool is the most commonly used specimen in the laboratory, proper (4) should be done so as to ensure a more accurate and reliable result.

Answer 14

collection
preservation
transportation
processing

Question 15

Proper_____ and proper______ for collecting materials must be provided to ensure satisfactory specimen for examination.

Answer 15

instructions

containers

Question 16

The following factors should be considered in collecting fecal specimens:

Answer 16

type of container
Size
age of the specimen
substances that might interfere with examinations

Question 17

The container should be (3) to accommodate a sample of adequate size.

Answer 17

clean, dry, and sufficiently large

Question 18

Container should be______, with a tight-fitting lid to prevent spills

Answer 18

leak proof

Question 19

______ and _____ should be recorded on the container or should accompany the specimen.

Answer 19

Information identifying the patient and the date and hour of passage

Question 20

Information in identifying the patient

Answer 20

Name
Age
Sex

Question 21

Ideally, unpreserved specimens should arrive in the laboratory within _____ after passage

Answer 21

1 to 2 hours

Question 22

To allow adequate macroscopic and microscopic examination, the________ should be submitted to the laboratory.

Answer 22

entire fecal passage

Question 23

Portion that is preferred for preparing smears for staining

Answer 23

soft and mucoid portion

Question 24

Portion that are used for concentration.

Answer 24

more formed portions

Question 25

is often useful in the diagnosis of Shistosoma mansoni and Entamoeba histolytica infections.

Answer 25

Surface material

Question 26

If the entire fecal specimens cannot be submitted, a quantity of about _____ should be provided to the laboratory.

Answer 26

20-30 grams

Question 27

if formed (size)

Answer 27

the size of a medium-size walnut

Question 28

if loose or watery (size or hm)

Answer 28

2-3 tablespoonful

Question 29

Several substances generally referred to as "________", will make the specimen unsuitable for parasitologic examinations.

Answer 29

interfering substances

Question 30

Interfering substances – will destroy trophozoites

Answer 30

Urine and water

Question 31

Interfering substances Feces contaminated with _____ and ____ is not suitable for examination.

Answer 31

soil and pollen

Question 32

Not only does_____ destroy trophozoites, but there is danger in free-living organisms contaminating the feces and making diagnosis difficult.

Answer 32

water

Question 33

Certain drugs and compounds will also render the stool specimens unsatisfactory for examination or for detection of organisms. Among these are:

Answer 33

antidiarrheal compounds Antibiotics Antacids Bismuth Barium antimalarial agents Oily laxatives such as mineral oil may also interfere with examination.

Question 34

– may decrease the number of organisms, especially protozoa, in the intestinal tract for several weeks

Answer 34

antibiotics or contrast media

Question 35

After barium and bismuth have been given Specimens should not be collected ___________ since crystals and particles of these compounds in the feces will interfere with examination and may destroy trophozoites by their abrasive action

Answer 35

7 to 10 days

Question 36

stools should not be collected in patients given gallbladder dye – until about ______ afterwards

Answer 36

3 weeks

Question 37

Specimens collected in very cold regions should not be allowed to freeze since_______ and _______ – may destroy protozoan cysts and trophozoites

Answer 37

freezing and thawing

Question 38

Portions of the specimen should be preserved for future examination and for staining. Most laboratories use a ________

Answer 38

two-vial technique

Question 39

two-vial technique: one portion of specimen is fixed in three parts of_________ and another portion in three parts of________

Answer 39

5-10% buffered formalin polyvinyl alcohol (PVA) fixative

Question 40

MIF

Answer 40

merthiolate-iodine-formalin

Question 41

SAF

Answer 41

sodium acetate-formalin (SAF)

Question 42

PVA

Answer 42

Polyvinyl alcohol

Question 43

Fixatives that contain mercury

Answer 43

Schaudinn's PVA fixatives

Question 44

Does not contain mercury

Answer 44

SAF

Question 45

the quality of ________ when using SAF is not as good as with Schaudinn's or PVA fixatives

Answer 45

permanent stains

Question 46

Best for concentration

Answer 46

Formalin

Question 47

Best for permanent stain

Answer 47

PVA

Question 48

The stool specimen should be submitted with the following information:

Answer 48

1. patient’s name 2. age 3. sex 4. date/time of collection 5. requesting physician 6. requested procedure 7. presumptive diagnosis 8. prior infections 9. travel history

Question 49

1. antacids 2. anti-diarrheals 3. barium 4. bismuth 5. laxatives All of these drugs have been found to leave_____ residues that can interfere with the identification of parasites. Stool samples should be collected _____ after the last intake of any of these drugs

Answer 49

crystalline week

Question 50

Intake of_____ usually decreases the number of protozoans for several weeks.

Answer 50

antibiotics

Question 51

Contamination with toilet water, urine, or soil must be prevented since these can destroy__________. In addition, soil and water may contain free-living organisms that would complicate diagnosis of infections.

Answer 51

protozoan trophozoites

Question 52

Age of the stool sample is very important for diarrheic specimens since the trophozoites it may contain are likely to die within____________ after passage. Therefore, stools must be examined within that period of time.

Answer 52

30 minutes to 1 hour

Question 53

Delay in examination of specimens may require______ to ensure that parasites are present in the identifiable stage.

Answer 53

preservation

Question 54

Temporary storage of fecal samples in a refrigerator______ is acceptable, but prolonged refrigeration can bring about desiccation. _______are killed by refrigeration, although______&_____ are usually not damaged.

Answer 54

(3-5°C) Trophozoites helminth eggs and protozoan cysts

Question 55

NEVER ______ STOOL SAMPLES. NEVER KEEP THEM IN______.

Answer 55

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