Infection Control and Safety — practice questions

10% of the exam ≈15 real questions 17 free questions here

15 scored items, and the most memorizable points on the whole exam — the sequences and categories do not change. Standard precautions, transmission-based precautions, PPE order, asepsis levels, sharps and the OSHA Bloodborne Pathogens Standard.

Where people lose points

• Alcohol-based hand rub does not kill C. difficile spores — that patient requires soap and water. This is the most commonly missed hand-hygiene item.
• Standard precautions apply to every patient regardless of diagnosis. Transmission-based precautions are added on top, never instead.
• Donning and doffing are not mirror images. Gloves go on last and come off first, because they are the most contaminated item.
• Disinfection and sterilization are not synonyms — sterilization destroys all microbial life including spores; high-level disinfection does not.
• Match the precaution to the organism: airborne for tuberculosis and measles, droplet for influenza and pertussis, contact for C. difficile and MRSA.

Questions and answers, explained

All 6 questions above, with the correct answer and why it is correct. Everything here is on infection control and safety.

1. A medical assistant has just assisted a patient with known Clostridioides difficile infection. The medical assistant's hands are not visibly soiled. What is the preferred hand hygiene method?

   • AWash the hands with soap and running waterCorrect
   • BUse an alcohol-based hand rub, which is preferred in every clinical situation
   • CUse an alcohol-based hand rub twice in a row
   • DApply an alcohol-based hand rub and then don a second pair of gloves

   Why: C. difficile forms spores that alcohol does not kill; CDC recommends soap and water after caring for a patient with known or suspected C. difficile because the friction and rinsing physically remove spores from the hands. Choice B is wrong because although alcohol rub is preferred in most clinical situations, spore-forming organisms and norovirus are documented exceptions.

   Reference Domain 3C (k101, k102); CDC hand hygiene / C. difficile prevention

2. What is the correct technique for using an alcohol-based hand rub?

   • AApply to the palms only and let them air-dry for about 5 seconds
   • BApply a small amount and wipe the excess off with a paper towel
   • CApply, then rinse with water after 10 seconds
   • DApply enough to cover all surfaces of both hands and rub until the hands are completely dryCorrect

   Why: CDC instructs personnel to cover all surfaces of the hands and fingers and rub until the hands feel completely dry, which should take about 20 seconds; drying time is the contact time. Choices B and C are wrong because wiping or rinsing removes the alcohol before the required contact time has elapsed, leaving organisms viable.

   Reference Domain 3C (k102); CDC hand sanitizer guidelines

3. Which feature defines an airborne infection isolation room (AIIR)?

   • APositive air pressure relative to the hallway, with at least 6 total air changes per hour
   • BNegative air pressure, at least 12 air changes per hour, air exhausted or HEPA-filteredCorrect
   • CA private room with a solid door and no special ventilation requirements at all
   • DA room with a portable HEPA unit and positive pressure to the corridor

   Why: CDC specifies that an AIIR is under negative pressure so air flows from the corridor into the room, provides at least 12 air changes per hour for construction since 2001 (at least 6 for older construction), and exhausts air outdoors or through a HEPA filter. Choices A and D are dangerous inversions: positive pressure would push contaminated air out into the corridor, and positive-pressure rooms are used to protect immunocompromised patients, not to contain pathogens.

   Reference Domain 3C (k96, k98); CDC environmental infection control - air

4. An 84-year-old patient receiving chemotherapy is at high risk of acquiring an infection during a clinic visit. Which link in the chain of infection does this patient represent?

   • AReservoir
   • BSusceptible hostCorrect
   • CPortal of exit
   • DInfectious agent

   Why: The susceptible host is the person whose defenses cannot resist an invading organism; advanced age, immunosuppressive therapy, chronic disease, and poor nutrition all increase susceptibility. Choice A is wrong because a reservoir is where the organism lives and multiplies before transmission, which describes the source rather than the person at risk of acquiring the infection.

   Reference Domain 3C (k94); CDC chain of infection

5. A medical assistant applies a sterile dressing to an open laceration. Which link in the chain of infection is being addressed?

   • AReservoir
   • BPortal of exit
   • CPortal of entryCorrect
   • DInfectious agent

   Why: Non-intact skin is a portal of entry, and covering the wound with a sterile barrier blocks organisms from entering the host at that opening. Choice B is the mirror image and is wrong here: a portal of exit is how an organism leaves an infected source, such as coughing or draining pus, whereas this patient's wound is the site at risk of being entered.

   Reference Domain 3C (k94, k104); CDC chain of infection

6. A small fire starts in a clinic supply closet. Using the RACE sequence, what should the medical assistant do first?

   • AAim the extinguisher at the base of the flames
   • BActivate the fire alarm
   • CRescue anyone in immediate dangerCorrect
   • DClose the closet door to confine the fire

   Why: RACE stands for Rescue, Alarm, Confine, Extinguish, and rescue comes first because patients may be unable to move themselves; only after people are moved to safety does the medical assistant pull the alarm, close doors to confine the fire, and consider an extinguisher. Choice A jumps to the last step and also skips the correct extinguisher method, PASS: Pull the pin, Aim at the base of the fire, Squeeze the handle, Sweep side to side.

   Reference Domain 3C (safety); OSHA portable fire extinguisher guidance (PASS); health care RACE protocol

Topics inside this domain

• Autoclave testing: spore tests and sterilizer monitoring
• Medical vs surgical asepsis and Spaulding
• OSHA Bloodborne Pathogens Standard duties
• PPE donning and doffing: the CDC order
• Sharps, regulated waste and the red bag
• Standard vs transmission-based precautions

Drill other domains

• Foundational Knowledge and Basic Science (10%)
• Anatomy and Physiology (5.3%)
• Patient Intake and Vitals (9.3%)
• General Patient Care (18.7%)
• Point of Care Testing and Laboratory Procedures (6%)
• Phlebotomy (8%)

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