Question 1

Which of the following is an effective disinfection process?

Accepted Answer

A)  Boiling at 100⁰C for 5 minutes.
B)  Boiling at 100⁰C for 30 minutes.
C)  Heating to 63⁰C for 30 minutes.
D)  Heating to 72⁰C for 15 seconds.
E)  All of the above.F) A) and D)
G) A) and C)

Question 2

In which of the following would a high-efficiency particulate air filter (HEPA) be used?

Accepted Answer

A)  To clean the air entering operating theatres.
B)  In laboratory biosafety cabinets to remove microbes from exhaust air.
C)  To trap pathogens in exhaust systems from isolation units.
D)  In respiratory masks.
E)  All of the above.F) A) and D)
G) B) and C) E

Question 3

What is most likely to happen to the bacteria in food which is placed in a refrigerator at 4⁰C?

Accepted Answer

A)  They die because bacteria cannot tolerate low temperatures.
B)  They continue to multiply but at a much reduced rate.
C)  They produce toxins which cause gastroenteritis when the food is eaten.
D)  They all form endospores in order to survive.
E)  They mutate in order to survive.F) A) and C)
G) D) and E)

Question 4

The removal of microorganisms from an object using a cleaning process is called

Accepted Answer

A)  antisepsis.
B)  sterilisation.
C)  disinfection.
D)  decontamination.
E)  pasteurisation.F) A) and B)
G) A) and C)

Question 5

Which of the following statements is FALSE?

Accepted Answer

A)  Gamma radiation can destroy all bacteria and viruses.
B)  Ionising radiation kills bacteria by disrupting the structure of their DNA.
C)  Gamma radiation sterilises because it can penetrate wrapped articles.
D)  Gamma radiation is useful for sterilising biological solutions for injection.
E)  Microwave radiation destroys all microorganisms by denaturing their proteins.F) A) and B)
G) B) and E)

Question 6

A kitchen sponge would be best decontaminated by

Accepted Answer

A)  placing it in a saucepan of boiling water for a few minutes.
B)  washing it in a household disinfectant.
C)  putting it in the freezer for a day.
D)  placing it in the microwave for a few seconds.
E)  none of the above.F) A) and D)
G) A) and C)

Question 7

Which commercially available antiseptic is preferred for surgical scrubs because it continues to provide antimicrobial activity on the skin for some time after use?

Accepted Answer

A)  Alcohol.
B)  Chlorhexidine.
C)  Hexachlorophene.
D)  Chlorine.
E)  Triclosan.F) C) and E)
G) B) and E)

Question 8

A piece of medical equipment that is considered to be semi-critical

Accepted Answer

A)  is one that is used in surgery.
B)  is one that comes into contact with a mucous membrane.
C)  should be cleaned but not disinfected before use.
D)  is one that is not directly used on a patient.
E)  can be re-used after careful decontamination.F) C) and D)
G) B) and C)

Question 9

A bactericide is a chemical agent which

Accepted Answer

A)  is effective against a range of microorganisms.
B)  inhibits bacterial replication.
C)  is used to sterilise the water supply.
D)  kills bacteria.
E)  is used to sterilise surgical instruments.F) A) and C)
G) None of the above

Question 10

A heat-sensitive,glass instrument is used on a patient known to have hepatitis B and becomes contaminated with small traces of the patient's blood.Before using it on the intact skin of another patient,which of the following would be the best way of disinfecting the instrument?

Accepted Answer

A)  Cleaning with soap and water followed by disinfection with sodium hypochlorite (household bleach) .
B)  Cleaning with soap and water followed by disinfection with any disinfectant available.
C)  Soaking the instrument in any disinfectant for several hours.
D)  Cleaning with soap and water is all that is necessary.
E)  None of the above because the instrument should not be used on any other patient.F) B) and D)
G) C) and D)

Question 11

In terms of processing requirements,a urinary catheter would be classified as

Accepted Answer

A)  critical.
B)  semi-critical.
C)  non-critical.
D)  low risk.
E)  moderate risk.F) B) and E)
G) B) and C)

Question 12

Which of the following methods is NOT a sterilising method?

Accepted Answer

A)  Autoclaving at 121⁰C.
B)  Treatment with ethylene oxide.
C)  Irradiation with gamma rays.
D)  Boiling at 100⁰C.
E)  Low temperature hydrogen peroxide.F) B) and D)
G) C) and E)

Question 13

Which of the following chemicals can have a sterilising effect?

Accepted Answer

A)  Alcohol.
B)  Phenol compounds.
C)  Ethylene oxide.
D)  Chlorine.
E)  Povidone-iodine.F) A) and C)
G) D) and E)

Question 14

Which of the following antiseptics is commonly used for skin disinfection before surgery?

Accepted Answer

A)  Hexachlorophene.
B)  Povidone-iodine.
C)  Triclosan.
D)  Alcohol.
E)  Glutaraldehyde.F) A) and C)
G) A) and E) B

Question 15

Which of the following statements is FALSE?

Accepted Answer

A)  A disinfection process removes only some bacteria and viruses.
B)  An item that has been disinfected may be used to penetrate healthy skin.
C)  Chemical disinfectants can be inactivated by organic material.
D)  Disinfection may only remove some pathogens.
E)  Washing equipment with hot water and detergent improves the effectiveness of disinfection procedures.F) A) and B)
G) D) and E)

Question 16

Which of the following statements is TRUE?

Accepted Answer

A)  Use of a disinfectant is not necessary for routine cleaning of surfaces.
B)  Bedrails and over-bed tables don't need regular cleaning.
C)  A dry surface is just as likely to harbour microorganisms as a wet surface.
D)  Physical cleaning is not necessary if the item is to be disinfected.
E)  All of the above.F) All of the above
G) D) and E)

Question 17

Chemical disinfectants

Accepted Answer

A)  do not guarantee total destruction of all microorganisms.
B)  can be easily inactivated.
C)  may be toxic to humans.
D)  may take several minutes or more to work.
E)  all of the above.F) B) and E)
G) A) and B)

Question 18

If a medical instrument is disinfected

Accepted Answer

A)  it is safe to use for any purpose.
B)  it is completely free of all microorganisms and spores.
C)  it has been subjected to a process that reduces the number of microbes present.
D)  it can only be used on a patient if it is in an airtight package.
E)  it must have been treated with some type of chemical.F) A) and E)
G) A) and D)

Question 19

If an instrument has been sanitised

Accepted Answer

A)  it has been cleaned but not necessarily disinfected or sterilised.
B)  it is completely free of all microorganisms and spores.
C)  the number of microbes on it has been reduced to an acceptable level.
D)  it has been subjected to a chemical that disinfects but doesn't sterilise.
E)  it is no longer contaminated.F) All of the above
G) B) and C)

Question 20

Which of the following influences the effectiveness of a chemical disinfection process?

Accepted Answer

A)  Length of exposure time.
B)  Concentration of disinfectant.
C)  Number of bacteria present.
D)  Presence of organic material.
E)  All of the above.F) B) and E)
G) A) and D) E

Exam 11: Principles of Sterilisation and Disinfection

Which of the following is an effective disinfection process?

Correct AnswerverifiedShow Answer

In which of the following would a high-efficiency particulate air filter (HEPA) be used?

Correct AnswerverifiedE

What is most likely to happen to the bacteria in food which is placed in a refrigerator at 4⁰C?

Correct AnswerverifiedShow Answer

The removal of microorganisms from an object using a cleaning process is called

Correct AnswerverifiedShow Answer

Which of the following statements is FALSE?

Correct AnswerverifiedShow Answer

A kitchen sponge would be best decontaminated by

Correct AnswerverifiedShow Answer

Which commercially available antiseptic is preferred for surgical scrubs because it continues to provide antimicrobial activity on the skin for some time after use?

Correct AnswerverifiedShow Answer

A piece of medical equipment that is considered to be semi-critical

Correct AnswerverifiedShow Answer

A bactericide is a chemical agent which

Correct AnswerverifiedShow Answer

A heat-sensitive,glass instrument is used on a patient known to have hepatitis B and becomes contaminated with small traces of the patient's blood.Before using it on the intact skin of another patient,which of the following would be the best way of disinfecting the instrument?

Correct AnswerverifiedShow Answer

In terms of processing requirements,a urinary catheter would be classified as

Correct AnswerverifiedShow Answer

Which of the following methods is NOT a sterilising method?

Correct AnswerverifiedShow Answer

Which of the following chemicals can have a sterilising effect?

Correct AnswerverifiedShow Answer

Which of the following antiseptics is commonly used for skin disinfection before surgery?

Correct AnswerverifiedB

Which of the following statements is FALSE?

Correct AnswerverifiedShow Answer

Which of the following statements is TRUE?

Correct AnswerverifiedShow Answer

Chemical disinfectants

Correct AnswerverifiedShow Answer

If a medical instrument is disinfected

Correct AnswerverifiedShow Answer

If an instrument has been sanitised

Correct AnswerverifiedShow Answer

Which of the following influences the effectiveness of a chemical disinfection process?

Correct AnswerverifiedE

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E

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B

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E