CBIC Ultimate CBIC 3 — Questions and Answers
Question 1: Which of the following is classified as a high-level disinfectant when used appropriately?
- Quaternary ammonium compounds
- Isopropyl alcohol 70%
- Glutaraldehyde 2% (Correct answer)
- Chlorhexidine gluconate 4%
Correct answer: Glutaraldehyde 2%
Glutaraldehyde 2% achieves high-level disinfection when items are immersed for the required contact time, destroying all microorganisms except high numbers of bacterial spores.
Question 2: The basic reproduction number (R0) of an infectious disease represents:
- The case fatality rate in susceptible populations
- The average number of secondary cases generated by one infectious person in a fully susceptible population (Correct answer)
- The proportion of the population that must be immune to achieve herd immunity
- The incubation period measured in standard deviations
Correct answer: The average number of secondary cases generated by one infectious person in a fully susceptible population
R0 represents the average number of new infections one case generates when introduced into a completely susceptible population with no interventions.
Question 3: Which of the following is the MOST effective method to prevent central line-associated bloodstream infections (CLABSIs)?
- Changing the central line every 72 hours
- Using antibiotic-impregnated catheters in all patients
- Implementing a central line insertion bundle (Correct answer)
- Applying topical antibiotic ointment to the insertion site daily
Correct answer: Implementing a central line insertion bundle
A central line insertion bundle — including hand hygiene, maximal sterile barrier precautions, chlorhexidine skin antisepsis, and daily assessment of line necessity — has the strongest evidence for CLABSI prevention.
Question 4: An infection preventionist notices that surgical site infection rates in orthopedic procedures have increased over the past two months. Which is the BEST initial action?
- Immediately implement enhanced cleaning protocols in all ORs
- Review case definitions and data collection methods for accuracy (Correct answer)
- Report the trend to the state health department
- Mandate preoperative chlorhexidine bathing for all patients
Correct answer: Review case definitions and data collection methods for accuracy
Before implementing interventions, the IP should first verify that the increase is real by reviewing case definitions and data quality to rule out surveillance artifact.
Question 5: Which PPE item is required when caring for a patient on contact precautions and entering the room to perform wound care?
- Gloves only
- Gown and gloves (Correct answer)
- Gloves, gown, and N95 respirator
- Surgical mask and gloves
Correct answer: Gown and gloves
Contact precautions require both a gown and gloves upon entry to the patient room, especially when contact with the patient or potentially contaminated surfaces is anticipated.
Question 6: Clostridium difficile spores are BEST eliminated from environmental surfaces using:
- Quaternary ammonium compound disinfectants
- Alcohol-based surface wipes
- Hypochlorite (bleach) solution at appropriate concentration (Correct answer)
- Hydrogen peroxide vapor at standard concentration
Correct answer: Hypochlorite (bleach) solution at appropriate concentration
C. difficile spores are resistant to most standard disinfectants and require sporicidal agents; EPA-registered sodium hypochlorite products at sufficient concentration are recommended.
Question 7: Which concept describes the minimum number of people who need to be immune in a population to prevent sustained disease transmission?
- Attack rate threshold
- Herd immunity threshold (Correct answer)
- Secondary attack rate
- Epidemic curve inflection point
Correct answer: Herd immunity threshold
The herd immunity threshold is the proportion of a population that must be immune (through vaccination or prior infection) to prevent an epidemic from spreading.
CBIC Ultimate CBIC 3
Which of the following is classified as a high-level disinfectant when used appropriately?