20 Infection Control & Safety Practice Questions & Answers

Every Infection Control & Safety practice question from the CCMA Practice Test (NHA Clinical Medical Assistant), with the correct answer and a short explanation.

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1. A patient with a cold coughs into a tissue and then throws it into a lined wastebasket. Covering the cough interrupts which link in the chain of infection?
- A.Infectious agent
- B.Susceptible host
- C.Portal of exit✓ Answer
- D.Portal of entry
The portal of exit is the route by which a pathogen leaves its reservoir; respiratory organisms leave through the nose and mouth when a person coughs or sneezes. Covering the cough traps the secretions at that exit point, so the organism never gets to a mode of transmission. It does not change the agent itself or the next person's susceptibility.
Ref QB-3Q8ZPRSource: NHA CCMA Test Plan — Domain 3C Infection Control: chain of infection (CDC respiratory hygiene/cough etiquette)Report a problem with this question
2. A medical assistant uses the same stethoscope on several patients without wiping it between uses, and a skin bacterium spreads from one patient to the next. Which mode of transmission is this?
- A.Droplet via large particles
- B.Vector-borne via an insect
- C.Airborne via droplet nuclei
- D.Indirect contact via a fomite✓ Answer
A fomite is a contaminated inanimate object, such as a stethoscope, that carries organisms from one person to another. Because the patients never touch each other, this is indirect rather than direct contact. Droplet and airborne spread require respiratory particles, and vector-borne spread requires a living carrier such as a mosquito or tick. Disinfecting shared equipment between patients breaks this route.
Ref QB-J73U4RSource: NHA CCMA Test Plan — Domain 3C Infection Control: modes of transmission (CDC Guideline for Isolation Precautions)Report a problem with this question
3. A child with suspected pertussis (whooping cough) is placed in an exam room. In addition to standard precautions, what should the medical assistant use when working close to the child?
- A.Gloves only, since standard precautions suffice
- B.A surgical mask for droplet precautions✓ Answer
- C.A fit-tested N95 for airborne precautions
- D.A gown and gloves for contact precautions
Pertussis spreads through large respiratory droplets that travel only a short distance (about 3 to 6 ft), so CDC assigns it to droplet precautions, which add a surgical mask to standard precautions. A fit-tested N95 and a negative-pressure room are reserved for airborne diseases such as tuberculosis, measles and varicella, and gown-and-gloves contact precautions target organisms spread by touch.
Ref QB-2QVNHQSource: CDC Guideline for Isolation Precautions — droplet precautions (Appendix A: pertussis)Report a problem with this question
4. A patient checking in is coughing and sneezing repeatedly in a crowded waiting room. Following respiratory hygiene and cough etiquette, what should the medical assistant do?
- A.Offer a mask and seat the patient at least 3 ft from others✓ Answer
- B.Have the patient wear gloves until the provider sees them
- C.Spray the waiting area with disinfectant while patients sit
- D.Ask the patient to wait outside until a room becomes free
CDC respiratory hygiene calls for source control at the first point of contact: give symptomatic patients a mask (or tissues) and separate them from others by at least 3 ft, ideally in a separate area. Masking the coughing person blocks droplets at the source. Sending the patient outside delays care, spraying disinfectant around seated people does not stop droplets and exposes them to chemicals, and gloves do nothing to contain respiratory secretions.
Ref QB-N75UMUSource: CDC Respiratory Hygiene/Cough Etiquette in Healthcare Settings (Standard Precautions)Report a problem with this question
5. A medical assistant will assist with irrigating an infected wound, and fluid is likely to splash toward the face. Which PPE combination is appropriate?
- A.A gown and a face shield, with no gloves
- B.Gloves, gown, and a mask with eye protection✓ Answer
- C.Gloves and a mask, with no gown or eyewear
- D.Gloves and a gown, with no face protection
PPE is chosen for the exposure you expect. Contact with body fluids requires gloves, a likely splash to clothing requires a gown, and a likely splash or spray toward the face requires a mask plus eye protection (goggles or a face shield) so the mouth, nose and eyes are all covered. Each other combination leaves at least one expected exposure unprotected.
Ref QB-5QXN2USource: OSHA Bloodborne Pathogens Standard 29 CFR 1910.1030(d)(3) — personal protective equipmentReport a problem with this question
6. When removing a used surgical mask after patient care, how should the medical assistant handle it?
- A.Touch only the ties or ear loops, then discard✓ Answer
- B.Fold it inward by the front and save it
- C.Remove it first, before taking off gloves
- D.Pull it off by the front, then discard it
The front of a used mask is considered contaminated, so CDC directs removing it by the ties or ear loops only and discarding it. The mask comes off last in the doffing sequence, after gloves, eye protection and gown, and hand hygiene follows immediately. Touching the front or saving a disposable mask moves contamination to the hands and face.
Ref QB-M7SGFTSource: CDC Sequence for Putting On and Removing PPE — removing the face maskReport a problem with this question
7. After helping a patient with a nosebleed, the medical assistant removes gloves and sees blood smeared on the back of one hand. What hand hygiene is required?
- A.Put on new gloves right away
- B.Wash with soap and running water✓ Answer
- C.Wipe with a disinfectant wipe
- D.Use an alcohol-based hand rub
CDC hand-hygiene guidance requires soap and water whenever hands are visibly soiled with blood or other body fluids, because alcohol-based rubs do not remove organic material. Alcohol rub is the preferred method only when hands are not visibly soiled. Surface disinfectant wipes are not made for skin, and new gloves would trap the blood against the hand.
Ref QB-4QKBVSSource: CDC Hand Hygiene in Healthcare Settings — soap and water when hands are visibly soiledReport a problem with this question
8. During a routine medical-aseptic handwash, how should the medical assistant hold the hands?
- A.Lower than the elbows, so water drains off the fingertips✓ Answer
- B.Level with the elbows, touching the inside of the sink
- C.Cupped under the faucet, rinsing without any friction
- D.Higher than the elbows, so water drains toward the wrists
In a medical-aseptic handwash the hands are held lower than the elbows so dirty water and microbes run off the fingertips into the sink rather than back up the arms. Holding the hands above the elbows is the surgical-scrub position, the inside of the sink is contaminated and must not be touched, and friction for at least 20 seconds is what mechanically removes microbes.
Ref QB-KEVUX3Source: NHA CCMA Test Plan — Domain 3C Infection Control: handwashing technique (CDC Hand Hygiene in Healthcare Settings)Report a problem with this question
9. Which task requires surgical asepsis rather than medical asepsis?
- A.Wiping the exam table between patients
- B.Taking an oral temperature with a cover
- C.Handling instruments for a skin biopsy✓ Answer
- D.Removing used linens from an exam room
Surgical asepsis (sterile technique) eliminates all microorganisms, including spores, and is required whenever an item will break the skin or enter sterile tissue, as biopsy instruments do. Medical asepsis (clean technique) only reduces the number and spread of microbes, which is enough for cleaning surfaces, taking an oral temperature and handling used linens.
Ref QB-3XPPC3Source: NHA CCMA Test Plan — Domain 3C Infection Control: medical vs surgical asepsisReport a problem with this question
10. While a sterile field is being set up, saline splashes onto the sterile drape and soaks through to the nonsterile table underneath. What should the medical assistant do?
- A.Cover the wet area with a folded sterile towel
- B.Proceed, since saline itself is a sterile solution
- C.Consider the field contaminated and set up a new one✓ Answer
- D.Blot the wet spot dry with a sterile gauze square
Moisture that soaks through a sterile barrier causes wicking (strike-through): it draws microorganisms up from the nonsterile surface below into the field. Once that happens the field is contaminated no matter how sterile the liquid was, and blotting or covering the spot cannot reverse it. The rule is that when sterility is in doubt, the field is considered contaminated and replaced.
Ref QB-DQ64JUSource: NHA CCMA Test Plan — Domain 3C Infection Control: aseptic technique (sterile field principles)Report a problem with this question
11. Reusable instruments with dried blood on them come back from a procedure. Wearing utility gloves, what should the medical assistant do first?
- A.Place them directly into the autoclave
- B.Rinse them in cool water to remove blood✓ Answer
- C.Rinse them in hot water to loosen blood
- D.Soak them in disinfectant without rinsing
Sanitization always comes before disinfection or sterilization, and it starts with a cool-water rinse because hot water coagulates blood proteins and bakes them onto the metal. Organic debris left on instruments shields microbes from steam or chemicals, so autoclaving or soaking dirty instruments can leave them unsterile. After rinsing, the instruments are scrubbed or ultrasonically cleaned, rinsed again and dried.
Ref QB-W7C95VSource: CDC Guideline for Disinfection and Sterilization in Healthcare Facilities — cleaning before disinfection/sterilizationReport a problem with this question
12. A reusable vaginal speculum contacts mucous membranes but does not enter sterile tissue. After cleaning, what is the minimum level of processing it needs under the Spaulding classification?
- A.Low-level disinfection
- B.High-level disinfection✓ Answer
- C.Rinsing with tap water only
- D.Sanitization with soap only
Spaulding sorts items by infection risk. Semi-critical items, which touch mucous membranes or non-intact skin, need at least high-level disinfection, which kills all vegetative microbes and most spores. Critical items that enter sterile tissue need sterilization, and low-level disinfection is only for non-critical items that touch intact skin. Cleaning alone never counts as disinfection.
Ref QB-CQTRCTSource: CDC Guideline for Disinfection and Sterilization in Healthcare Facilities — Spaulding classification (semi-critical items)Report a problem with this question
13. How should wrapped instrument packs be loaded into a steam autoclave?
- A.Wrapped with hinged instruments fully closed
- B.Pressed against the chamber walls and door
- C.Stacked flat and tightly to fill the chamber
- D.On edge, with space between packs for steam✓ Answer
An autoclave sterilizes by putting pressurized steam in contact with every surface, so the load must let steam circulate. Packs go on edge with space between them and away from the chamber walls, and hinged instruments are wrapped open so steam reaches the joints. Tight stacking, crowding the walls or closing hinges creates air pockets where the steam cannot reach and leaves items unsterile.
Ref QB-V7ZWXTSource: CDC Guideline for Disinfection and Sterilization in Healthcare Facilities — steam sterilization loadingReport a problem with this question
14. After a blood spill is cleaned up, a medical assistant sprays an EPA-registered disinfectant on the countertop. What determines whether the surface has been properly disinfected?
- A.It stays wet for the label's contact time✓ Answer
- B.It is sprayed twice, then left to air
- C.It is wiped dry right after spraying
- D.It smells of the product after drying
Every EPA-registered disinfectant lists a contact (wet) time, the period the surface must stay visibly wet for the product to kill the organisms named on the label. Wiping it dry early or letting it evaporate too soon stops the kill before it is complete, and the number of sprays or a lingering smell says nothing about whether the contact time was met. The EPA registers disinfectants; OSHA requires that blood-contaminated surfaces be decontaminated.
Ref QB-BQFE7SSource: CDC Guideline for Disinfection and Sterilization — EPA-registered disinfectant label contact time; OSHA 29 CFR 1910.1030(d)(4)(ii)Report a problem with this question
15. A medical assistant pours disinfectant from the manufacturer's bottle into a smaller spray bottle that staff will use over the next several weeks. Under the OSHA Hazard Communication Standard, what is required?
- A.Tape a copy of the full SDS to the spray bottle instead
- B.Mark only the date it was filled on the spray bottle
- C.Label the spray bottle with the product name and hazards✓ Answer
- D.Leave it unlabeled, because the SDS is kept on file
The Hazard Communication Standard requires secondary (workplace) containers to carry a label with the product identifier and its hazards, so anyone who picks up the bottle later knows what it is and how it can hurt them. Having the SDS on file does not replace the container label, and a fill date or a taped SDS does not meet the labeling requirement. The narrow exemption for unlabeled containers covers only immediate use by the employee who filled them.
Ref QB-U7NKSSSource: OSHA Hazard Communication Standard 29 CFR 1910.1200(f)(6) — workplace (secondary) container labelingReport a problem with this question
16. Under OSHA's definition of regulated waste, which item from a minor procedure must go into a red biohazard bag rather than the regular trash?
- A.An adhesive bandage wrapper from the procedure
- B.A glove with no visible blood on its surface
- C.Gauze that would release blood if compressed✓ Answer
- D.A paper drape with one small, dry spot of blood
OSHA defines regulated waste to include items saturated with blood or OPIM that would release blood in a liquid or semi-liquid state if compressed, or that have caked dried blood able to flake off during handling. Such items go into a red or biohazard-labeled, leak-resistant container. Items that are unsoiled or only lightly spotted and cannot release blood are not regulated waste and are handled per facility policy.
Ref QB-AQ442RSource: OSHA Bloodborne Pathogens Standard 29 CFR 1910.1030(b) — definition of regulated wasteReport a problem with this question
17. A patient's blood splashes into a medical assistant's eyes. At the eyewash station, how long should the eyes be flushed?
- A.For roughly 2 minutes
- B.For about 30 seconds
- C.Until the stinging stops
- D.For at least 15 minutes✓ Answer
The eyewash standard (ANSI Z358.1) designs stations to deliver a continuous flush for at least 15 minutes, which is how long it takes to rinse contaminants out of the eye. A short flush, or stopping when it no longer stings, can leave infectious material on the conjunctiva. After flushing, the medical assistant reports the exposure right away so a post-exposure medical evaluation can begin.
Ref QB-T7A9MRSource: ANSI Z358.1 emergency eyewash standard; OSHA Bloodborne Pathogens Standard 29 CFR 1910.1030(f)(3) — post-exposure evaluationReport a problem with this question
18. After a needlestick involving a source patient known to have HIV, the medical assistant has washed the site and reported it. If HIV post-exposure prophylaxis is recommended, when should it ideally start?
- A.At the 6-week follow-up visit for testing
- B.Only if the MA's own HIV test turns positive
- C.Within 7 days, once source results return
- D.As soon as possible, ideally within 2 hours✓ Answer
HIV post-exposure prophylaxis works by stopping the virus before infection becomes established, so it is most effective when started within hours, ideally within 2 hours, and it should begin no later than 72 hours after exposure. Waiting for source results, for a positive test or for the follow-up visit lets the window close. This is why the exposure must be reported immediately and the evaluation done without delay.
Ref QB-HQKE8ZSource: U.S. Public Health Service/CDC guidelines for occupational HIV exposure and post-exposure prophylaxis; OSHA 29 CFR 1910.1030(f)(3)Report a problem with this question
19. During a morning check, the medical assistant notices that yesterday afternoon's vaccine refrigerator temperature reading was never recorded on the log. What is the correct action?
- A.Leave the blank and document the missed reading per policy✓ Answer
- B.Remove the page and start a new, complete log sheet
- C.Copy today's reading into yesterday's blank space
- D.Enter yesterday's usual reading so the log is complete
A temperature log is a legal compliance record, so each entry must reflect a reading actually taken, with date, time, reading and initials. A missed reading is left blank and documented according to facility policy, often with a check of the unit's min/max data so any excursion can be addressed. Filling in a guessed or copied value, or rewriting the page, falsifies the record.
Ref QB-28SKTZSource: NHA CCMA Test Plan — Domain 3C Infection Control and Safety: logs (temperature); CDC Vaccine Storage and Handling Toolkit — temperature monitoringReport a problem with this question
20. During a respiratory disease outbreak, the health department asks people who were exposed but have no symptoms to stay home for a set period. What is this control measure called?
- A.Isolation of exposed people
- B.Herd immunity in the community
- C.Standard precautions at home
- D.Quarantine of exposed people✓ Answer
Quarantine separates and restricts the movement of people who were exposed to a contagious disease but are not sick, to see whether they become ill. Isolation separates people who are already sick from those who are not. Standard precautions are infection-control practices used with every patient in health care, and herd immunity is the indirect protection that comes from widespread immunity, not a movement restriction.
Ref QB-AN6XZQSource: CDC Quarantine and Isolation guidance — control of epidemics and pandemicsReport a problem with this question

1. A patient with a cold coughs into a tissue and then throws it into a lined wastebasket. Covering the cough interrupts which link in the chain of infection?

2. A medical assistant uses the same stethoscope on several patients without wiping it between uses, and a skin bacterium spreads from one patient to the next. Which mode of transmission is this?

3. A child with suspected pertussis (whooping cough) is placed in an exam room. In addition to standard precautions, what should the medical assistant use when working close to the child?

4. A patient checking in is coughing and sneezing repeatedly in a crowded waiting room. Following respiratory hygiene and cough etiquette, what should the medical assistant do?

5. A medical assistant will assist with irrigating an infected wound, and fluid is likely to splash toward the face. Which PPE combination is appropriate?

6. When removing a used surgical mask after patient care, how should the medical assistant handle it?

7. After helping a patient with a nosebleed, the medical assistant removes gloves and sees blood smeared on the back of one hand. What hand hygiene is required?

8. During a routine medical-aseptic handwash, how should the medical assistant hold the hands?

9. Which task requires surgical asepsis rather than medical asepsis?

10. While a sterile field is being set up, saline splashes onto the sterile drape and soaks through to the nonsterile table underneath. What should the medical assistant do?

11. Reusable instruments with dried blood on them come back from a procedure. Wearing utility gloves, what should the medical assistant do first?

12. A reusable vaginal speculum contacts mucous membranes but does not enter sterile tissue. After cleaning, what is the minimum level of processing it needs under the Spaulding classification?

13. How should wrapped instrument packs be loaded into a steam autoclave?

14. After a blood spill is cleaned up, a medical assistant sprays an EPA-registered disinfectant on the countertop. What determines whether the surface has been properly disinfected?

15. A medical assistant pours disinfectant from the manufacturer's bottle into a smaller spray bottle that staff will use over the next several weeks. Under the OSHA Hazard Communication Standard, what is required?

16. Under OSHA's definition of regulated waste, which item from a minor procedure must go into a red biohazard bag rather than the regular trash?

17. A patient's blood splashes into a medical assistant's eyes. At the eyewash station, how long should the eyes be flushed?

18. After a needlestick involving a source patient known to have HIV, the medical assistant has washed the site and reported it. If HIV post-exposure prophylaxis is recommended, when should it ideally start?

19. During a morning check, the medical assistant notices that yesterday afternoon's vaccine refrigerator temperature reading was never recorded on the log. What is the correct action?

20. During a respiratory disease outbreak, the health department asks people who were exposed but have no symptoms to stay home for a set period. What is this control measure called?

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