Isolation Precautions by Organism

In depth

The one-page summary above is what the PDF prints. These sections go further.

Why the route sets the precaution

Every precaution answers one question: how does this organism reach the next person? Standard precautions assume any blood, body fluid, nonintact skin or mucous membrane can carry an infection, so they apply to every client whether or not a diagnosis is known. Transmission-based precautions are added on top when an organism spreads in a way standard care would not stop (CDC 2007).

• Contact: the organism lives on skin, in stool or wound drainage, and on the bed rail, the BP cuff and the call light. Hands and clothing carry it, so the barrier is a gown and gloves for anything touching the client or the room, plus dedicated equipment.
• Droplet: large droplets from coughing, sneezing or talking fall within a short distance, so a surgical mask on entry, at least 3 ft between beds and a drawn curtain protect the people nearby. Nobody far away is exposed, so normal room air is fine.
• Airborne: tiny particles (droplet nuclei) stay suspended and drift on air currents. Distance and a surgical mask do not protect, so the room must pull air in from the corridor (negative pressure) and staff need a sealed respirator.

Some organisms need two tiers. Varicella and disseminated zoster are airborne from the lungs and contact from lesion fluid, so both apply until the lesions crust. A draining extrapulmonary TB lesion is airborne plus contact (Appendix A). COVID-19 is handled with an N95, gown, gloves and eye protection in a single room, which combines elements of all three.

Contact organisms: MRSA, VRE, C. difficile, RSV and scabies

Multidrug-resistant organisms (MRSA, VRE and others) are contact organisms, whether they cause infection or only colonize. CDC leaves the details to each facility's infection control program but recommends contact precautions where transmission is ongoing, in higher-risk acute care settings and for wounds whose drainage a dressing cannot contain (Appendix A). CDC 2007 notes it may be prudent to assume carriers stay colonized, so many hospitals keep the flag for the whole stay and on readmission; one approach removes it only after a period free of hospital stays, antibiotics and invasive devices (for example 6 or 12 months).

C. difficile forms spores. Alcohol rub does not kill them, and even hand washing may not remove them all, which is why CDC calls gloves the key protection. Appendix A prefers soap and water for hand hygiene, and exams expect it every time. IDSA/SHEA 2017 adds the detail: soap and water is preferred during outbreaks and after direct contact with stool, while alcohol rub is acceptable in routine care. Other rules from IDSA/SHEA 2017: start contact precautions as soon as C. diff is suspected, before the result (CDC; strong when results are not back the same day), use a private room with its own toilet (strong), use disposable or dedicated equipment (strong), and continue precautions at least 48 h after diarrhea resolves (weak); Appendix A says only for the duration of illness. Clean the room daily with an EPA List K sporicidal disinfectant, such as a bleach (hypochlorite) product (CDC 2026; IDSA/SHEA 2017).

RSV spreads mainly through hands and surfaces contaminated with secretions. Appendix A lists contact precautions for infants, young children and immunocompromised adults for the duration of illness, extended in immunocompromised clients because they shed virus for weeks; a mask is worn as standard precautions require. Many pediatric units add droplet precautions, so answer with the contact core and follow facility policy.

Scabies mites pass by skin-to-skin contact and through clothing and bedding: contact precautions until 24 h after effective treatment starts. Head lice follow the same 24-hour rule, but body and pubic lice need only standard precautions (Appendix A).

Droplet organisms: influenza, pertussis, meningococcus, mumps and rubella

Suspected bacterial meningitis is treated as meningococcal until the organism is known, so droplet precautions start on admission, before the lumbar puncture result. After 24 h of effective antibiotics the client is no longer infectious, and precautions stop.

Influenza is droplet, but some procedures create aerosols: bronchoscopy, sputum induction, intubation and extubation, CPR and open suctioning. For those, CDC asks for a fit-tested N95, gown, gloves and a face shield or goggles, an AIIR when feasible, and only the staff essential to the procedure in the room.

Airborne organisms: TB, measles, varicella and zoster, and COVID-19

Tuberculosis: pulmonary or laryngeal TB, suspected or confirmed, needs an AIIR and N95s. Suspected TB comes off precautions when infectious TB is judged unlikely and either another diagnosis explains the illness or 3 sputum smears are negative. Confirmed TB comes off only when the client is improving on effective therapy and has 3 consecutive negative AFB smears collected on separate days (Appendix A); CDC 2005 collects them 8–24 h apart with at least one early-morning specimen. Exams often add 2 weeks of therapy for home release; in hospital the smears and clinical response decide.

Measles: airborne precautions until 4 days after rash onset (rash day is day 0), and for the whole illness in immunocompromised clients. Every staff member wears an N95 or better, even with presumptive immunity, and visitors without immunity do not enter. When the client leaves, the room stays empty for up to 2 hours to remove 99.9% of airborne virus. Exposed patients without immunity go on airborne precautions from day 5 through day 21 after exposure (CDC 2025).

Varicella and disseminated zoster: airborne plus contact until every lesion is dry and crusted (zoster: duration of illness), with only immune staff assigned. Localized zoster in a healthy client with covered lesions needs only standard precautions; in an immunocompromised client it is treated as disseminated until proven otherwise. Exposed staff without immunity are excluded from day 8 after first exposure through day 21 after the last, or day 28 if VariZIG was given (CDC 2026).

COVID-19 (Appendix A interim text): single room, door closed when safe, staff in an N95, gown, gloves and eye protection, and an AIIR for aerosol-generating procedures when possible. Precautions end after at least 10 days with 24 h fever-free and improving symptoms in mild to moderate illness, 10–20 days in severe illness, and by a test-based strategy (two negative tests 48 h apart) in moderately to severely immunocompromised clients.

PPE and respirators in practice

Donning runs from the body outward and ends with gloves, so the glove cuff covers the gown cuff. Doffing removes the dirtiest items first: gloves, then eyewear, then the gown rolled inside out, then the mask by its ties without touching the front. Everything comes off at the doorway or in the anteroom except a respirator, which is removed after leaving the room and closing the door. Clean hands whenever they become contaminated during doffing and immediately after the last item (CDC poster).

An N95 filters at least 95% of airborne particles, but only through a sealed edge. OSHA requires a medical evaluation, then a fit test before first use, at least yearly, with any new model or size, and after changes such as facial scarring, dental work, cosmetic surgery or obvious weight change. A user seal check is done every time it is put on, and facial hair that crosses the seal is not allowed. A seal check does not replace a fit test (NIOSH).

Rooms, cohorting and transport

An AIIR is a single room under negative pressure (at least 0.01 inch of water lower than the corridor) with at least 6 air changes an hour in older rooms and 12 in new or renovated ones; its air goes outside or through a HEPA filter. The door stays closed, and the pressure is checked daily while it is in use (CDC 2005). A protective environment is the opposite: positive pressure, HEPA-filtered incoming air and more than 12 air changes an hour, to keep mold spores away from allogeneic stem cell transplant recipients (IDSA 2010; CDC 2007 says at least 12).

Cohorting means rooming clients with the same organism when single rooms run out, after consulting infection prevention. Cohort only confirmed infections with the same pathogen: two influenza A clients, or two C. diff clients, but never C. diff with MRSA or VRE (IDSA/SHEA 2017) and never an undiagnosed rash. Appendix A names cohorting as an option for pertussis, and CDC lists it for influenza when no single room is free.

• Limit transport to essential trips and tell the receiving department ahead so the client does not wait in a hallway.
• Contact: cover or contain the infected site, remove contaminated PPE and clean hands before leaving, put on clean PPE at the destination, and clean shared equipment such as the stretcher before the next client (CDC 2024).
• Droplet and airborne: a surgical mask on the client and infectious lesions covered. The transporter then needs no respirator for an airborne client (CDC 2024), though CDC 2005 says staff transporting a TB client might consider one.

Neutropenic and protective precautions

Neutropenic precautions reverse the usual question: the client is not contagious; everyone else is the risk. IDSA defines neutropenia as an ANC below 500/mm³ or one expected to fall below 500 within 48 h. The core is hand hygiene by everyone, which IDSA calls the most effective way to prevent transmission in the hospital, not masks or gowns. Airborne isolation is wrong for a neutropenic client with no communicable infection.

• Room: private for transplant recipients; allogeneic transplant rooms have positive pressure, HEPA and over 12 air changes an hour (IDSA 2010, CDC 2000).
• No plants or fresh or dried flowers: potting soil and arrangements carry Aspergillus (CDC 2000, IDSA 2010).
• No rectal temperatures, rectal exams, enemas or suppositories, which break mucosa (CDC 2000).
• Food: well-cooked meat, fish and eggs; no unpasteurized milk or juice (CDC 2000, NCI).
• Avoid crowds, sick people and anyone who has just had a live vaccine (NCI); after a stem cell transplant someone else cleans the litter box (CDC 2000).
• Fever of 38 °C (100.4 °F) or higher is reported at once (CDC); it may be the only sign of infection (IDSA 2010).

Teaching visitors and families

Visitors follow the same logic as staff, adjusted for the fact that family members have often been exposed already. CDC 2007 notes that relatives already exposed to TB or varicella at home would not need masks, while visiting health care workers would. SHEA 2015 guidance: every visitor cleans hands before entering and on leaving; gowns and gloves are not routinely recommended for MRSA or VRE; gowns and gloves are suggested for C. diff and norovirus; surgical masks for droplet precautions; surgical masks (or N95s, which need fit testing) for TB, with household contacts often excused; and symptomatic visitors restricted. CDC 2005 offers TB visitors respirators with instruction before entry.

• Measles: visitors without presumptive immunity do not enter (CDC 2025).
• Influenza: limit in-person visits while the client is infectious, offer video calls, teach hand hygiene and PPE before entry (CDC 2026).
• COVID-19: limit visits, teach hand hygiene and PPE, and keep visitors in the client's room (CDC 2023).
• Stem cell transplant: screen visitors for colds, flu-like illness and active shingles; children may visit only if they can follow hand-washing rules (CDC 2000).

The NCLEX frames this as teaching: when a visitor ignores the sign, the nurse provides the PPE and explains why, rather than banning the visitor or asking the client to wear the mask instead.

Worked NCLEX-style examples

1. One AIIR is open, and four clients need rooms: influenza, MRSA in a wound, C. diff, and a cough with night sweats and a cavity on x-ray. Who gets it? The suspected TB client: only airborne organisms need negative pressure, and suspicion is enough to start precautions.
2. A nurse leaves the room of a client with C. diff and uses the alcohol rub at the door. Which action needs correction? This one: spores survive alcohol, so wash with soap and water.
3. A client with disseminated zoster needs a nurse. Who should not be assigned? The pregnant nurse with no varicella history or vaccine: susceptible staff stay out when immune staff are available (Appendix A).
4. A client with meningococcal meningitis has had ceftriaxone for 30 hours and asks why staff still wear masks. Best response: droplet precautions can stop after 24 h of effective antibiotics, so check the order and discontinue per policy.
5. A client on airborne precautions for TB must go to radiology. Correct: a surgical mask on the client and radiology notified ahead. Wrong: an N95 on the client, or no mask because the hallway is ventilated.
6. The spouse of a neutropenic client arrives with a cold and a bouquet. Best action: kindly ask them not to visit until well, offer a phone or video call, and leave the flowers outside the room.

Common traps: choosing airborne for influenza or meningitis, putting the N95 on the client, cohorting an undiagnosed rash, using droplet precautions for MRSA or C. diff, and confusing protective (positive-pressure) with airborne (negative-pressure) rooms.

Exam pearls

• Airborne: measles, varicella, disseminated zoster and TB; N95 for staff, AIIR, surgical mask on the client to leave.
• Droplet: influenza, pertussis, meningococcus, mumps, rubella; mask on entry, client masked to leave the room.
• Contact: MRSA, VRE, C. diff, RSV, scabies, head lice; gown and gloves on entry and dedicated equipment.
• C. diff: soap and water, sporicidal (bleach) cleaning, private room with its own toilet.
• Gloves on last, off first; respirator off last, outside the room with the door closed.
• N95: fit test before first use and yearly; seal check every time; no beard under the seal.
• Negative pressure keeps germs in (airborne); positive pressure keeps germs out (protective environment).
• Immune staff for measles, mumps, varicella and zoster; measles still needs an N95; non-immune pregnant staff never care for rubella.
• Neutropenic: hand hygiene, no flowers or plants, no rectal routes, report 38 °C at once, screen visitors.
• End points: 24 h (meningococcus, scabies), 5 days (pertussis antibiotics, mumps swelling), 7 days (rubella), 4 days after rash (measles), crusted lesions (varicella), 3 negative smears (TB).