Tuberculosis (Mycobacterium tuberculosis)
TB precautions
- How long
- Until CDC’s discontinuation criteria are met (see below)
- Room
- Airborne infection isolation room (AIIR), door closed
- PPE
- Fit-tested N95 or higher respirator on entry
- Stop (confirmed)
- On effective therapy, improving clinically, and 3 consecutive negative AFB sputum smears collected on separate days
- Stop (suspected)
- Only when infectious TB is deemed negligible and either another diagnosis explains the illness or 3 AFB sputum smears are negative (collected 8–24 hours apart, at least one early morning)
Good to know
- Extrapulmonary TB with a draining lesion needs Airborne + Contact Precautions until the patient improves and drainage stops or three consecutive cultures of the drainage are negative.
- Extrapulmonary TB without drainage, including TB meningitis, needs only Standard Precautions — but check for pulmonary disease. A positive skin test with no active disease needs Standard Precautions.
What CDC’s table says
Verbatim from CDC’s Appendix A, with bibliography numbers removed.
Tuberculosis (M. tuberculosis) — Pulmonary or laryngeal disease, confirmed
AirborneStandardDuration—
Discontinue precautions only when patient on effective therapy is improving clinically and has 3 consecutive sputum smears negative for acid-fast bacilli collected on separate days (MMWR 2005; 54: RR-17 Guidelines for Preventing the Transmission of Mycobacterium tuberculosis in Health-Care Settings, 2005).
Tuberculosis (M. tuberculosis) — Pulmonary or laryngeal disease, suspected
AirborneStandardDuration—
Discontinue precautions only when the likelihood of infectious TB disease is deemed negligible, and either there is another diagnosis that explains the clinical syndrome, or the results of 3 sputum smears for AFB are negative. Each of the 3 sputum specimens should be collected 8 -24 hours apart, and at least 1 should be an early morning specimen.
Tuberculosis (M. tuberculosis) — Extrapulmonary, draining lesion
AirborneContactStandardDuration—
Discontinue precautions only when patient is improving clinically, and drainage has ceased or there are 3 consecutive negative cultures of continued drainage. Examine for evidence of active pulmonary tuberculosis.
Tuberculosis (M. tuberculosis) — Extrapulmonary, no draining lesion, Meningitis
StandardDuration—
Examine for evidence of pulmonary tuberculosis. For infants and children, use Airborne until active pulmonary tuberculosis in visiting family members ruled out.
Tuberculosis (M. tuberculosis) — Skin-test positive with no evidence of current active disease
StandardDuration—
Test yourself: a CIC-style question
A patient has confirmed active pulmonary tuberculosis. When can Airborne Precautions be discontinued?
- When a full course of anti-tuberculosis therapy is complete
- When the patient is on effective therapy, improving clinically, and has 3 consecutive negative AFB sputum smears
- When the patient stops coughing
- Only at hospital discharge
Show answer
B. When the patient is on effective therapy, improving clinically, and has 3 consecutive negative AFB sputum smears
CDC’s Appendix A requires all three for confirmed pulmonary TB: effective therapy, clinical improvement, and three consecutive sputum smears negative for acid-fast bacilli collected on separate days.
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 precautions are needed for TB?
- Airborne + Standard (pulmonary or laryngeal TB, suspected or confirmed). Room: Airborne infection isolation room (AIIR), door closed. PPE: Fit-tested N95 or higher respirator on entry. Stop (confirmed): On effective therapy, improving clinically, and 3 consecutive negative AFB sputum smears collected on separate days. Stop (suspected): Only when infectious TB is deemed negligible and either another diagnosis explains the illness or 3 AFB sputum smears are negative (collected 8–24 hours apart, at least one early morning).
- How long do TB precautions last?
- Until CDC’s discontinuation criteria are met (see below).
Sources
- CDC. Appendix A: Type and Duration of Precautions Recommended for Selected Infections and Conditions (2007 Guideline for Isolation Precautions, updated September 2024)
- CDC. 2007 Guideline for Isolation Precautions: Summary of Recommendations
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.