ADEX Infection Control Principles 2 — Questions and Answers
Question 1: Which CDC transmission-based precaution category is used for patients with pulmonary tuberculosis?
- Contact precautions
- Droplet precautions
- Airborne precautions (Correct answer)
- Standard precautions only
Correct answer: Airborne precautions
Pulmonary TB requires airborne precautions because M. tuberculosis spreads via small droplet nuclei that remain suspended in air.
Question 2: What is the minimum contact time required for a hospital-grade intermediate-level surface disinfectant to be effective?
- 10 seconds
- 30 seconds
- The manufacturer's stated wet-contact time (Correct answer)
- 5 minutes always
Correct answer: The manufacturer's stated wet-contact time
The EPA-registered disinfectant must remain visibly wet on the surface for the full manufacturer-specified contact time to achieve the labeled kill claim.
Question 3: A dental hygienist sustains a needlestick from a patient with unknown HIV status. What is the FIRST action to take?
- Immediately report to the supervisor
- Flush the wound with soap and water for several minutes (Correct answer)
- Begin post-exposure prophylaxis within 72 hours
- Document the incident in the patient record
Correct answer: Flush the wound with soap and water for several minutes
Immediate decontamination by washing with soap and water is the first step before any reporting or prophylaxis decisions.
Question 4: Which item classification requires sterilization before reuse on another patient?
- Non-critical items that contact intact skin
- Semicritical items like mouth mirrors
- Critical items that penetrate soft tissue or bone (Correct answer)
- Environmental surfaces touched during treatment
Correct answer: Critical items that penetrate soft tissue or bone
Spaulding's classification defines critical items as those that penetrate tissue or bone, requiring sterilization to eliminate all microbial life including spores.
Question 5: The biological indicator used to verify autoclave sterilization effectiveness contains spores of which organism?
- Staphylococcus aureus
- Bacillus atrophaeus or Geobacillus stearothermophilus (Correct answer)
- Mycobacterium tuberculosis
- Clostridium difficile
Correct answer: Bacillus atrophaeus or Geobacillus stearothermophilus
Geobacillus stearothermophilus (steam) and Bacillus atrophaeus (dry heat) spores are the most heat-resistant test organisms used in biological indicators.
Question 6: When donning PPE before a dental procedure, what is the correct order?
- Gloves → mask → eyewear → gown
- Gown → mask → eyewear → gloves (Correct answer)
- Mask → eyewear → gown → gloves
- Eyewear → gown → gloves → mask
Correct answer: Gown → mask → eyewear → gloves
OSHA and CDC recommend gown first, then mask, then protective eyewear, then gloves to prevent cross-contamination during donning.
Question 7: Which waterborne pathogen is most commonly associated with dental unit waterline contamination?
- Legionella pneumophila
- Pseudomonas aeruginosa
- Both Legionella and heterotrophic bacteria within biofilm (Correct answer)
- Hepatitis B virus
Correct answer: Both Legionella and heterotrophic bacteria within biofilm
Dental waterlines harbor polymicrobial biofilms containing heterotrophic bacteria and potentially Legionella, posing risk especially to immunocompromised patients.
ADEX Infection Control Principles 2
Which CDC transmission-based precaution category is used for patients with pulmonary tuberculosis?