CSFA Microbiology and Infection Control 4 — Questions and Answers
Question 1: Which of the following is the correct sequence for donning sterile attire in the OR?
- Gloves → Gown → Mask → Cap
- Cap → Mask → Gown → Gloves (Correct answer)
- Mask → Cap → Gloves → Gown
- Gown → Gloves → Cap → Mask
Correct answer: Cap → Mask → Gown → Gloves
The correct order is cap first (to contain hair), then mask (to protect airway/droplets), then surgical hand antisepsis, then gown, then gloves.
Question 2: What is the primary purpose of using a sterile drape with an iodine-impregnated adhesive incise film (e.g., Ioban)?
- To mark the incision site for the surgeon
- To reduce SSI risk by immobilizing skin flora at the incision site (Correct answer)
- To provide hemostasis at the skin edges
- To prevent instrument tips from touching the patient's skin
Correct answer: To reduce SSI risk by immobilizing skin flora at the incision site
Iodine-impregnated incise drapes kill resident skin flora and mechanically isolate the incision site to prevent microbial migration into the wound.
Question 3: A scrub person notices that a sterile package has a small hole in the outer wrap. The CORRECT action is to:
- Use it if the inner wrap is intact
- Consider the item non-sterile and obtain a replacement (Correct answer)
- Reinforce the hole with sterile tape and use the item
- Inspect the contents under a light and use if visually clean
Correct answer: Consider the item non-sterile and obtain a replacement
Package integrity is essential to sterility maintenance; any breach in packaging — even a pinhole — renders the contents non-sterile.
Question 4: Which bloodborne pathogen has the HIGHEST risk of transmission following a needlestick injury from an infected patient?
- HIV
- Hepatitis C virus (HCV)
- Hepatitis B virus (HBV) (Correct answer)
- Cytomegalovirus (CMV)
Correct answer: Hepatitis B virus (HBV)
Hepatitis B virus has a transmission risk of up to 30% per needlestick from an HBsAg-positive source, significantly higher than HCV (~3%) or HIV (<1%).
Question 5: In Spaulding's classification, an endoscope used for bronchoscopy (touching non-intact mucosa) requires at minimum:
- Low-level disinfection
- Intermediate-level disinfection
- High-level disinfection (Correct answer)
- Terminal sterilization
Correct answer: High-level disinfection
Semi-critical items (contact with mucous membranes or non-intact skin) require high-level disinfection to eliminate all microorganisms except high numbers of bacterial spores.
Question 6: During an airborne infection isolation procedure (e.g., TB patient), the surgical team should wear at minimum:
- Standard surgical masks
- N95 respirators fit-tested to each individual (Correct answer)
- Powered air-purifying respirators (PAPRs) only
- Double-layered surgical masks
Correct answer: N95 respirators fit-tested to each individual
N95 respirators filter at least 95% of airborne particles and must be fit-tested to the individual user to be effective against Mycobacterium tuberculosis.
Question 7: Which of the following correctly describes a 'break in sterile technique' that requires immediate action?
- A scrubbed team member turns sideways to pass an instrument
- An unscrubbed circulator opens a sterile supply by tearing the package
- A scrubbed team member reaches across the sterile field with an ungloved hand (Correct answer)
- The back table is set 12 inches from the OR bed
Correct answer: A scrubbed team member reaches across the sterile field with an ungloved hand
An ungloved (unscrubbed) hand crossing over or into the sterile field immediately contaminates it and requires the field to be re-established.
CSFA Microbiology and Infection Control 4
Which of the following is the correct sequence for donning sterile attire in the OR?