Study guide · concept · Infection control & safety
Contact, droplet and airborne precautions on the CCMA
Transmission-based precautions come in three tiers. Airborne (TB, measles, varicella) calls for a fit-tested N95 and a negative-pressure room. Droplet (influenza, pertussis, meningitis) calls for a surgical mask at close range, roughly 3–6 ft. Contact (MRSA, VRE, C. diff, scabies) calls for a gown and gloves.
- transmission-based tiers
- 3
- airborne, fit-tested
- N95
- droplet range
- 3–6 ft
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Standard precautions come first
Every patient gets standard precautions. The three tiers are add-ons.
Standard precautions apply to every patient. Blood, all body fluids except sweat, non-intact skin and mucous membranes are treated as infectious. Transmission-based precautions are added on top when a disease spreads in a way that standard precautions don't stop. Bloodborne pathogens such as HBV, HCV and HIV stay on standard precautions, because gloves and sharps safety already cover their route.
In the chain of infection, all three tiers break the same link: the mode of transmission. That's also why hand hygiene is the single most effective habit on the infection control study page.
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The three tiers at a glance
Learn three diseases per tier and the rest sort themselves.
| Precaution | Spreads by | Classic diseases | Staff PPE | Room |
|---|---|---|---|---|
| Contact | Touching the patient or contaminated surfaces and equipment | MRSA, VRE, C. diff, scabies | Gown and gloves on entry | Dedicated or disinfected equipment |
| Droplet | Large respiratory droplets from coughing or sneezing | Influenza, pertussis, meningitis | Surgical mask at close range (3–6 ft) | Close-range protection is the point |
| Airborne | Tiny particles that stay suspended in room air | Tuberculosis, measles, varicella | Fit-tested N95 respirator | Negative-pressure airborne infection isolation room (AIIR) |
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How far each tier reaches
Distance is the quickest way to tell droplet from airborne.
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Sort by route
Ask in this order and stop at the first yes.
Does it stay in the air?
If particles small enough to drift through a room carry it, it's airborne. Staff need filtration (the N95) and the room needs air control.
Is it coughed or sneezed out at close range?
Large droplets fall within a few feet, so it's droplet. A surgical mask covers that range.
Is it picked up from skin, wounds, stool or surfaces?
That's contact: gown and gloves, with equipment kept to the room or disinfected.
None of the above
Standard precautions alone.
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Between the tiers
Coughing spreads both droplet and airborne diseases. What tells them apart?
The particle size. Droplets are heavy and fall within a few feet. Airborne particles are small enough to stay suspended, so they need a respirator that filters them and a room that controls where the air goes.
Do standard precautions stop when transmission-based precautions start?
No. Transmission-based precautions are added on top of standard precautions.
Why does a negative-pressure room still need staff in N95s?
The room stops contaminated air from escaping into the hallway. The respirator protects the person breathing inside the room. Each does a different job.
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Precaution questions
10 questions. Pick an answer to see why it is right or wrong.
Name the route before you read the options. Most wrong answers belong to the tier next to the right one.
A child with suspected measles arrives at the clinic. Which transmission-based precautions are required?
Answer & explanation
Answer: B. Airborne
Measles, like tuberculosis and varicella, spreads on tiny particles that stay suspended in the air, so it needs airborne precautions: an N95 respirator for staff and an airborne infection isolation room. Droplet precautions, used for influenza or pertussis, protect only within a few feet. Contact and standard precautions do not address organisms that stay suspended in air.
- Standard precautions alone are not enough for measles, which spreads through the air.
- Correct: measles spreads by airborne particles, requiring a fit-tested N95 and an airborne infection isolation room.
- Droplet precautions cover flu and pertussis; measles particles stay suspended longer and travel farther.
- Contact precautions address touch-spread organisms like MRSA, not airborne measles.
Contact precautions are used primarily to interrupt organisms transmitted by:
Answer & explanation
Answer: C. Direct or indirect touching of the patient or surfaces
Contact precautions (gown and gloves) target pathogens such as MRSA and C. difficile that spread by direct patient contact or indirect contact with contaminated surfaces. Airborne and droplet precautions address suspended particles and large droplets instead.
- Large droplets spread within a few feet are handled by droplet precautions with a surgical mask.
- Small particles suspended in room air call for airborne precautions with an N95.
- Correct: contact precautions target organisms spread by touching the patient or contaminated surfaces, like MRSA or C. difficile.
- Foodborne and waterborne spread is controlled through food safety, not transmission-based isolation precautions.
Which respiratory protection should a medical assistant wear when rooming a patient with suspected active tuberculosis?
Answer & explanation
Answer: A. Fit-tested N95 respirator
TB spreads on airborne particles small enough to pass around and through a surgical mask, so staff wear an N95 respirator that has been fit-tested to seal to the face. Adding a face shield does not filter air. An N95 without a fit test may leak at the edges and is not compliant; the patient wears a surgical mask to contain their own droplets.
- Correct: suspected active TB requires a fit-tested N95 respirator that filters small airborne particles.
- A surgical mask with a face shield blocks splashes but does not seal against airborne TB particles.
- A surgical mask stops large droplets, not the tiny airborne nuclei that carry TB.
- An N95 only protects when it seals properly, so fit testing is required, not optional.
Which patient requires droplet precautions?
Answer & explanation
Answer: A. A child with pertussis
Pertussis spreads on large respiratory droplets that travel only a few feet, so a surgical mask is worn within that distance. Measles is airborne and needs an N95 and an isolation room, C. difficile needs contact precautions with soap-and-water hand hygiene, and hepatitis B is bloodborne and needs only standard precautions.
- Correct: pertussis spreads by large respiratory droplets, so it requires droplet precautions with a surgical mask.
- C. difficile spreads through spores on hands and surfaces, requiring contact precautions instead.
- Hepatitis B is bloodborne and is handled with standard precautions alone.
- Measles is airborne, needing an N95 and an isolation room, more than droplet precautions.
A patient with suspected active tuberculosis arrives for evaluation. Where should the patient be placed?
Answer & explanation
Answer: A. Negative-pressure isolation room
Airborne diseases such as TB require an airborne infection isolation room with negative pressure, which pulls air in and exhausts it safely; the patient wears a surgical mask during transport. A mask in the waiting room still exposes others for a long time, a standard room recirculates air to the hallway, and a positive-pressure room pushes contaminated air out toward others — the opposite of what is needed.
- Correct: negative pressure keeps TB particles from escaping into hallways, which is why an airborne isolation room is used.
- A shared waiting room exposes others even if the patient wears a mask; prompt isolation is needed.
- Positive pressure pushes room air outward, spreading airborne particles into the hallway.
- A standard room with the door closed does not control airflow enough for airborne TB.
A patient has a draining wound infected with MRSA. Which precautions are required in addition to standard precautions?
Answer & explanation
Answer: D. Contact: gown and gloves
MRSA spreads by direct contact and via contaminated surfaces and equipment, so contact precautions require a gown and gloves on entering the room, plus dedicated or disinfected equipment. A surgical mask and an N95 protect against droplet and airborne spread, which are not the main routes here. Standard precautions alone underprotect a patient with draining infected wounds.
- Gloves alone are not enough for MRSA wound drainage; contact precautions add a gown.
- MRSA spreads by contact, not through the air, so an N95 is not the needed precaution.
- Droplet precautions are for respiratory infections like flu, not a draining MRSA wound.
- Correct: MRSA spreads by direct and indirect contact, so a gown and gloves are added to standard precautions.
A patient with a diagnosis of active pulmonary tuberculosis needs to be transported for an X-ray. What is the appropriate infection control measure during transport?
Answer & explanation
Answer: C. The patient should wear a surgical mask during transport
A patient with active pulmonary tuberculosis should wear a surgical mask during transport to contain respiratory secretions at the source. The N95 respirator is worn by healthcare workers caring for the patient, not by the patient themselves.
- Needed imaging should not wait; the risk is managed with source control during transport.
- Negative-pressure rooms are for isolation in place; a short trip needs no special chamber.
- Correct: a surgical mask on the patient traps respiratory droplets at the source while moving.
- The N95 protects the staff; for the patient, a surgical mask is the source-control choice.
A patient with suspected chickenpox (varicella) requires which combination of precautions?
Answer & explanation
Answer: A. Airborne plus contact precautions
Varicella spreads through the air and through contact with vesicle fluid, so both airborne and contact precautions are used. Droplet-only or standard-only precautions would not contain airborne viral particles.
- Correct: varicella spreads through the air and by contact with lesions, so airborne plus contact precautions apply.
- Varicella is airborne, so droplet precautions fall short even when contact precautions are added.
- Standard precautions alone do not protect against airborne spread or contact with draining lesions.
- Droplet precautions alone miss both the airborne route and direct contact with lesions.
A patient has C. difficile diarrhea and a new productive cough with influenza suspected. Which precautions apply?
Answer & explanation
Answer: C. Contact plus droplet precautions
C. difficile calls for contact precautions and suspected influenza adds droplet precautions, so both are combined. Contact or standard precautions alone omit droplet protection, and neither condition is airborne.
- Standard precautions always apply, but both conditions need transmission-based precautions on top.
- Neither C. difficile nor influenza is airborne, so an N95 and isolation room are not required.
- Correct: C. difficile calls for contact precautions, and suspected influenza adds droplet precautions.
- Contact alone covers the diarrhea but leaves the coughing patient's droplets unaddressed.
A patient with pertussis is coughing. Under droplet precautions, when must staff wear a surgical mask?
Answer & explanation
Answer: C. Within about 3 to 6 feet of the patient
Large respiratory droplets typically travel about 3 to 6 feet, so a surgical mask is worn within that range for droplet precautions. Droplets do not stay suspended across a building, and protection is needed close to the patient.
- Touching the patient is the trigger for contact precautions; droplet risk starts at close range without any touch.
- Droplets fall within a few feet, so masking throughout the building is not what droplet precautions require.
- Correct: droplet precautions focus on close range, roughly 3 to 6 feet, where heavy respiratory droplets land.
- Masking only beyond 10 feet reverses the logic; close range is where droplet risk is highest.
That is the whole set. Open any card to re-read its explanation, or start over.
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