NCWO Infection Prevention and Control 1 — Questions and Answers
Question 1: Which of the following best defines a critically colonized wound?
- A wound with no microbial presence
- A wound with bacteria causing tissue damage and delayed healing without systemic signs (Correct answer)
- A wound with systemic signs of infection such as fever and leukocytosis
- A wound that has been sterilized with antiseptic solution
Correct answer: A wound with bacteria causing tissue damage and delayed healing without systemic signs
Critical colonization refers to a wound where bacteria have multiplied to levels that impair healing and cause local tissue damage but have not yet triggered a systemic response.
Question 2: According to wound infection principles, what bacterial count per gram of tissue is generally considered the threshold for clinical infection?
- 10^3 organisms per gram
- 10^5 organisms per gram (Correct answer)
- 10^7 organisms per gram
- 10^9 organisms per gram
Correct answer: 10^5 organisms per gram
A bacterial count of ≥10^5 organisms per gram of tissue is the classic threshold associated with impaired wound healing and clinical infection.
Question 3: Which hand hygiene method is most effective against Clostridioides difficile spores?
- Alcohol-based hand rub for 20 seconds
- Soap and water handwashing for at least 20 seconds (Correct answer)
- Chlorhexidine gluconate scrub for 10 seconds
- Povidone-iodine hand wash for 15 seconds
Correct answer: Soap and water handwashing for at least 20 seconds
Alcohol-based hand rubs do not kill C. difficile spores; soap and water physically removes spores through mechanical action and rinsing.
Question 4: When caring for a patient with a methicillin-resistant Staphylococcus aureus (MRSA) wound infection, which isolation precaution level is required?
- Standard precautions only
- Airborne precautions
- Contact precautions (Correct answer)
- Droplet precautions
Correct answer: Contact precautions
MRSA is transmitted through direct contact with infected wounds or contaminated surfaces, so contact precautions (gown and gloves) are required in addition to standard precautions.
Question 5: Which clinical sign is MOST specific for identifying wound infection in a chronic wound?
- Wound odor
- Increased exudate volume
- Increased pain or change in pain character (Correct answer)
- Wound edges that appear macerated
Correct answer: Increased pain or change in pain character
New or increased pain, or a change in the character of pain (e.g., from dull to sharp), is one of the most specific indicators of infection in chronic wounds, where classic signs may be absent.
Question 6: What is the recommended technique for collecting a wound culture to obtain the most clinically meaningful results?
- Swab the wound surface after removing exudate
- Swab purulent drainage directly from the wound bed
- Use the Levine technique: firmly rotate a swab over a 1 cm² area for 5 seconds (Correct answer)
- Aspirate from the outer wound margin with a needle and syringe
Correct answer: Use the Levine technique: firmly rotate a swab over a 1 cm² area for 5 seconds
The Levine technique—rotating a swab firmly over a 1 cm² area of clean wound tissue for 5 seconds with enough pressure to express fluid—produces the most representative quantitative wound culture.
Question 7: Biofilm in a chronic wound is best described as:
- A single layer of bacteria on the wound surface that responds readily to topical antibiotics
- A structured community of microorganisms encased in a self-produced extracellular matrix (Correct answer)
- A type of necrotic tissue that must be surgically debrided
- A protein layer formed by the host immune response to protect the wound
Correct answer: A structured community of microorganisms encased in a self-produced extracellular matrix
Biofilm is a structured polymicrobial community encased in an extracellular polysaccharide matrix that provides significant resistance to antibiotics and host immune defenses.
