Microbiology and Immunology

Infection control principles Practice Questions

20 free Infection control principles practice questions for the USMLE Step 1, each with the correct answer and a detailed explanation. Open any question below, or take the full set as an interactive quiz.

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All Infection control principles questions

20 questions
  1. Q1. A healthcare worker performs hand hygiene after removing gloves. Which statement best explains why this step is necessary?
  2. Q2. Which method is most effective at inactivating bacterial spores on surgical instruments?
  3. Q3. A patient with Clostridioides difficile infection is placed on which type of precautions?
  4. Q4. Which pathogen requires airborne precautions in a hospital setting?
  5. Q5. A patient with suspected meningococcal meningitis should be placed under which precautions?
  6. Q6. A nurse touches a contaminated wound and then adjusts her face mask without performing hand hygiene. Which type of transmission is most likely?
  7. Q7. Which disinfectant is most effective against enveloped viruses such as influenza?
  8. Q8. Which scenario requires sterilization rather than disinfection?
  9. Q9. A healthcare worker caring for a patient with MRSA should use which precautions?
  10. Q10. A patient with varicella (chickenpox) is admitted. What combination of precautions is required?
  11. Q11. A nurse recaps a used needle and accidentally sustains a finger-stick injury. What is the most important immediate step?
  12. Q12. Which type of hand hygiene is required after caring for a patient with norovirus?
  13. Q13. A hospital wants to reduce central line–associated bloodstream infections. Which intervention is most effective?
  14. Q14. A patient with active measles is admitted. What preventive measure must all healthcare workers entering the room take?
  15. Q15. Which statement best describes standard precautions?
  16. Q16. Which organisms are NOT reliably inactivated by alcohol-based hand sanitizers?
  17. Q17. A patient with suspected pertussis is admitted. Which precautions are needed?
  18. Q18. Which of the following items requires high-level disinfection rather than sterilization?
  19. Q19. An outbreak of Pseudomonas in a burn unit is traced to contaminated sink drains. What infection control measure is most effective?
  20. Q20. A hospitalized patient with scabies requires what type of precautions?