CDC Infection Preventionist Post Test Questions
and Answers with Rationales Latest 2025
This reflects the latest CDC guidelines and core principles for infection
preventionists as of 2024.
1. What is the most effective method for preventing the spread of healthcare-
associated infections (HAIs)?
Hand hygiene
Proper hand hygiene remains the single most important action to reduce
the spread of infections in healthcare settings.
2. According to CDC guidelines, what type of precautions should be used for a
patient with suspected tuberculosis?
Airborne precautions
TB is transmitted via airborne particles; therefore, airborne precautions
and a negative pressure room are required.
3. Which personal protective equipment (PPE) is required when caring for a
patient on contact precautions?
Gloves and gown
Contact precautions require gloves and gowns when entering the
patient’s room to prevent contamination of clothing and hands.
,4. What is the recommended duration for handwashing with soap and water
when hands are visibly soiled?
At least 20 seconds
The CDC recommends scrubbing hands with soap and water for at least 20
seconds to remove dirt and germs.
5. Which organism is known for being resistant to alcohol-based hand
sanitizers and requires handwashing with soap and water?
Clostridioides difficile
C. difficile spores are not killed by alcohol-based hand rubs; handwashing
with soap and water is required.
6. Which element is NOT a component of Standard Precautions?
Negative pressure room
Negative pressure rooms are part of Airborne Precautions, not Standard
Precautions.
7. What is the first step in donning PPE?
Hand hygiene
Performing hand hygiene is always the first step before donning PPE to
reduce contamination risk.
8. What is the correct order for doffing PPE?
Gloves, gown, eye protection, mask, hand hygiene
This order minimizes self-contamination during removal.
9. What type of precaution is required for a patient with influenza?
Droplet precautions
, Influenza is spread via large respiratory droplets, so droplet precautions
are indicated.
10.What is the CDC’s minimum recommended air exchanges per hour (ACH)
for an airborne infection isolation room?
12 ACH for new construction
New construction airborne isolation rooms should have at least 12 air
exchanges per hour to reduce airborne pathogens.
11.For disinfection of surfaces contaminated with norovirus, what type of
disinfectant is recommended?
EPA-registered bleach-based disinfectant
Norovirus is resistant to many disinfectants; bleach-based products are
effective.
12.What is an example of an engineering control to reduce sharps injuries?
Needleless IV systems
Engineering controls like needleless systems reduce the risk of needlestick
injuries.
13.Which term describes the time between exposure to an infectious agent
and the appearance of symptoms?
Incubation period
The incubation period is the time from exposure to symptom onset.
14.According to the CDC, how often should reusable medical equipment be
cleaned and disinfected?
After each patient use
, Reusable equipment must be cleaned and disinfected after each use to
prevent cross-contamination.
15.What level of disinfection is required for semi-critical items like
endoscopes?
High-level disinfection
Semi-critical items that contact mucous membranes require high-level
disinfection.
16.Which statement best describes Standard Precautions?
They apply to all patients, regardless of diagnosis.
Standard Precautions are used with every patient to prevent transmission
of infections.
17.What is the minimum alcohol concentration for effective hand rubs
according to CDC?
At least 60% alcohol
Hand sanitizers should contain at least 60% alcohol for effective germ
killing.
18.What is the chain of infection component that represents a way for an
infectious agent to leave its reservoir?
Portal of exit
The portal of exit is how a pathogen leaves its reservoir.
19.Which of the following is NOT an element of transmission-based
precautions?
Antimicrobial stewardship
and Answers with Rationales Latest 2025
This reflects the latest CDC guidelines and core principles for infection
preventionists as of 2024.
1. What is the most effective method for preventing the spread of healthcare-
associated infections (HAIs)?
Hand hygiene
Proper hand hygiene remains the single most important action to reduce
the spread of infections in healthcare settings.
2. According to CDC guidelines, what type of precautions should be used for a
patient with suspected tuberculosis?
Airborne precautions
TB is transmitted via airborne particles; therefore, airborne precautions
and a negative pressure room are required.
3. Which personal protective equipment (PPE) is required when caring for a
patient on contact precautions?
Gloves and gown
Contact precautions require gloves and gowns when entering the
patient’s room to prevent contamination of clothing and hands.
,4. What is the recommended duration for handwashing with soap and water
when hands are visibly soiled?
At least 20 seconds
The CDC recommends scrubbing hands with soap and water for at least 20
seconds to remove dirt and germs.
5. Which organism is known for being resistant to alcohol-based hand
sanitizers and requires handwashing with soap and water?
Clostridioides difficile
C. difficile spores are not killed by alcohol-based hand rubs; handwashing
with soap and water is required.
6. Which element is NOT a component of Standard Precautions?
Negative pressure room
Negative pressure rooms are part of Airborne Precautions, not Standard
Precautions.
7. What is the first step in donning PPE?
Hand hygiene
Performing hand hygiene is always the first step before donning PPE to
reduce contamination risk.
8. What is the correct order for doffing PPE?
Gloves, gown, eye protection, mask, hand hygiene
This order minimizes self-contamination during removal.
9. What type of precaution is required for a patient with influenza?
Droplet precautions
, Influenza is spread via large respiratory droplets, so droplet precautions
are indicated.
10.What is the CDC’s minimum recommended air exchanges per hour (ACH)
for an airborne infection isolation room?
12 ACH for new construction
New construction airborne isolation rooms should have at least 12 air
exchanges per hour to reduce airborne pathogens.
11.For disinfection of surfaces contaminated with norovirus, what type of
disinfectant is recommended?
EPA-registered bleach-based disinfectant
Norovirus is resistant to many disinfectants; bleach-based products are
effective.
12.What is an example of an engineering control to reduce sharps injuries?
Needleless IV systems
Engineering controls like needleless systems reduce the risk of needlestick
injuries.
13.Which term describes the time between exposure to an infectious agent
and the appearance of symptoms?
Incubation period
The incubation period is the time from exposure to symptom onset.
14.According to the CDC, how often should reusable medical equipment be
cleaned and disinfected?
After each patient use
, Reusable equipment must be cleaned and disinfected after each use to
prevent cross-contamination.
15.What level of disinfection is required for semi-critical items like
endoscopes?
High-level disinfection
Semi-critical items that contact mucous membranes require high-level
disinfection.
16.Which statement best describes Standard Precautions?
They apply to all patients, regardless of diagnosis.
Standard Precautions are used with every patient to prevent transmission
of infections.
17.What is the minimum alcohol concentration for effective hand rubs
according to CDC?
At least 60% alcohol
Hand sanitizers should contain at least 60% alcohol for effective germ
killing.
18.What is the chain of infection component that represents a way for an
infectious agent to leave its reservoir?
Portal of exit
The portal of exit is how a pathogen leaves its reservoir.
19.Which of the following is NOT an element of transmission-based
precautions?
Antimicrobial stewardship
