GI Safety & Infection Control 2 — Questions and Answers
Question 1: Which level of disinfection is required for endoscopes that contact mucous membranes but do not penetrate sterile tissue?
- Low-level disinfection
- High-level disinfection (Correct answer)
- Sterilization
- Intermediate-level disinfection
Correct answer: High-level disinfection
Endoscopes are semi-critical items that contact mucous membranes and require high-level disinfection to eliminate all microorganisms except bacterial spores.
Question 2: A patient with Clostridioides difficile (C. diff) colitis is admitted. Which isolation precaution is most appropriate?
- Airborne precautions
- Droplet precautions
- Contact precautions (Correct answer)
- Standard precautions only
Correct answer: Contact precautions
C. diff is transmitted via the fecal-oral route through spores on surfaces and hands, requiring contact precautions with a private room.
Question 3: Why is alcohol-based hand sanitizer NOT effective against Clostridioides difficile spores?
- Spores are too large for alcohol to penetrate
- Alcohol does not kill bacterial spores (Correct answer)
- Alcohol evaporates too quickly
- Spores are protected by a protein shell
Correct answer: Alcohol does not kill bacterial spores
Alcohol-based sanitizers are ineffective against C. diff because they cannot kill bacterial endospores; soap and water with mechanical friction is required.
Question 4: Before performing an upper endoscopy (EGD), which action is most important for infection prevention?
- Applying antifungal spray to the scope
- Verifying the scope has completed high-level disinfection (Correct answer)
- Flushing the scope with normal saline only
- Wiping the scope exterior with alcohol wipes
Correct answer: Verifying the scope has completed high-level disinfection
Verifying that the endoscope has completed high-level disinfection per manufacturer protocol is the critical step to prevent patient-to-patient pathogen transmission.
Question 5: A nurse preparing to change a colostomy bag should don which PPE as the minimum standard?
- N95 respirator and face shield
- Sterile gloves and gown
- Clean gloves only (Correct answer)
- Gloves and gown
Correct answer: Clean gloves only
Standard precautions for ostomy care require clean (non-sterile) gloves at minimum to protect against contact with fecal material.
Question 6: Which organism is most commonly associated with foodborne gastroenteritis outbreaks in healthcare facilities?
- Helicobacter pylori
- Norovirus (Correct answer)
- Giardia lamblia
- Campylobacter jejuni
Correct answer: Norovirus
Norovirus is the leading cause of healthcare-associated gastroenteritis outbreaks due to its low infectious dose and environmental stability.
Question 7: When reprocessing flexible endoscopes, what is the correct order of steps?
- Disinfect → Pre-clean → Rinse → Dry
- Pre-clean → Leak test → Clean → High-level disinfect → Rinse → Dry (Correct answer)
- Rinse → Clean → Disinfect → Pre-clean
- Clean → Sterilize → Pre-clean → Dry
Correct answer: Pre-clean → Leak test → Clean → High-level disinfect → Rinse → Dry
The correct reprocessing sequence is pre-clean at bedside, leak test, manual cleaning, high-level disinfection, rinsing, then drying and storage.
GI Safety & Infection Control 2
Which level of disinfection is required for endoscopes that contact mucous membranes but do not penetrate sterile tissue?