An airborne infection isolation room: a single-patient room at negative pressure relative to the surrounding area, with at least 6 air changes per hour (12 for new construction), air exhausted outside or HEPA-filtered, and the door kept closed.

Which diseases require Airborne Precautions?

In CDC’s Appendix A: pulmonary or laryngeal tuberculosis (suspected or confirmed), measles, varicella (chickenpox), disseminated herpes zoster or localized zoster in an immunocompromised patient until dissemination is ruled out, smallpox, SARS, and tuberculosis with draining extrapulmonary lesions.

Isolation precautions

Airborne Precautions

Airborne Precautions are added to Standard Precautions for infections spread by small particles that stay infectious in the air over long distances: pulmonary or laryngeal tuberculosis, measles, chickenpox (varicella), disseminated shingles, and smallpox.

Room: airborne infection isolation room (AIIR)

A single-patient room at negative pressure relative to the surrounding area.
At least 6 air changes per hour in existing facilities, 12 for new construction or renovation.
Air is exhausted directly outside, or passed through a HEPA filter before it is recirculated.
Keep the door closed, and monitor air pressure daily with visual indicators (such as smoke tubes or flutter strips) while the room is in use.
If no AIIR is available, mask the patient, place them in a private room with the door closed, and transfer them to a facility that has one.

PPE and staffing

Wear a fit-tested, NIOSH-approved N95 or higher-level respirator when entering the room.
Staff who are not immune to measles, chickenpox or smallpox should not enter those patients’ rooms when immune staff are available.
For measles, CDC recommends N95-level protection for everyone entering the room, regardless of presumptive evidence of immunity.

Transport

Limit transport and movement outside the room to medically necessary purposes.
The patient wears a surgical mask and follows respiratory hygiene and cough etiquette.
Cover skin lesions from varicella, smallpox or draining tuberculosis.

After an unprotected exposure

Measles: vaccine within 72 hours, or immune globulin within 6 days.
Varicella: vaccine as soon as possible and within 120 hours; varicella zoster immune globulin within 10 days for exposed people who cannot be vaccinated.
Smallpox: vaccine within 4 days of exposure.

Conditions that need Airborne Precautions

All 8 entries in CDC’s Appendix A that include Airborne Precautions, with CDC’s duration.

Herpes zoster (varicella-zoster) (shingles) — Disseminated disease in any patient — Localized disease in immunocompromised patient until disseminated infection ruled out
AirborneContactStandardShingles guide
DurationDuration of illness
Measles (rubeola)
AirborneStandardMeasles guide
Duration4 days after onset of rash; duration of illness in immune compromised
Severe acute respiratory syndrome (SARS)
AirborneDropletContactStandard
DurationDuration of illness plus 10 days after resolution of fever, provided respiratory symptoms are absent or improving
Smallpox (variola; see Vaccinia for management of vaccinated persons)
AirborneContactStandard
DurationDuration of illness
Tuberculosis (M. tuberculosis) — Extrapulmonary, draining lesion
AirborneContactStandardTB guide
Duration—
Tuberculosis (M. tuberculosis) — Pulmonary or laryngeal disease, confirmed
AirborneStandardTB guide
Duration—
Tuberculosis (M. tuberculosis) — Pulmonary or laryngeal disease, suspected
AirborneStandardTB guide
Duration—
Varicella Zoster
AirborneContactStandardChickenpox guide
DurationUntil lesions dry and crusted

Test yourself: a CIC-style question

Which personal protective equipment is required before entering the room of a patient on Airborne Precautions?

Surgical mask
N95 (or higher) respirator
Face shield only
Gown and gloves only

Show answer

B. N95 (or higher) respirator

Airborne Precautions require a fit-tested N95 or higher-level respirator (such as a PAPR) before entry. A surgical mask does not reliably protect against small airborne particles.

Questions like this come up in the Preventing and Controlling the Transmission of Infectious Agents domain of the CIC® exam. The 654 questions in the app each come with a written explanation.

FAQ

What is an AIIR?: An airborne infection isolation room: a single-patient room at negative pressure relative to the surrounding area, with at least 6 air changes per hour (12 for new construction), air exhausted outside or HEPA-filtered, and the door kept closed.
Which diseases require Airborne Precautions?: In CDC’s Appendix A: pulmonary or laryngeal tuberculosis (suspected or confirmed), measles, varicella (chickenpox), disseminated herpes zoster or localized zoster in an immunocompromised patient until dissemination is ruled out, smallpox, SARS, and tuberculosis with draining extrapulmonary lesions.

Sources

Checked against CDC on October 21, 2026. For education and CIC® exam preparation only — not a substitute for your facility’s infection prevention policies, your state or local health department, or clinical judgment. CBIC and CDC do not endorse this tool.