What are the isolation precautions for tuberculosis (TB)?

Tuberculosis Isolation Precautions

Patients with suspected or confirmed tuberculosis must be placed in airborne infection isolation (AII) rooms with negative pressure until they have received effective treatment, shown clinical improvement, and produced three consecutive negative sputum AFB smears collected on different days. 1

Airborne Isolation Requirements

Room Specifications

• Negative pressure room relative to surrounding areas 2, 1
• At least 6 air changes per hour (ACH) 2, 1
• Air exhausted directly outside or through HEPA filters if recirculated 2, 1
• Doors must remain closed at all times to maintain directional airflow 2, 1
• Direction of air flow should be monitored frequently using flutter strips or smoke tubes 2

Personal Protective Equipment

• Healthcare workers must wear properly fitted N95 respirators or higher when entering isolation rooms 2, 1
• Patients must wear surgical masks when leaving the isolation room for essential procedures 2, 1

Duration of Isolation

Standard Cases

• Isolation may be discontinued when:
  • Patient is receiving effective anti-TB therapy
  • Patient is showing clinical improvement
  • Three consecutive sputum AFB smears collected on different days are negative 2, 1
• This typically occurs within 2-3 weeks after starting appropriate treatment 2, 1

Drug-Resistant Cases

• For MDR-TB: Consider continued isolation throughout hospitalization 1
• For XDR-TB: Patients should remain in respiratory isolation until cultures are negative 1
• Early molecular testing for drug resistance is critical to determine appropriate isolation duration 1

Special Situations

Transport Requirements

• When transport outside the isolation room is necessary:
  • Patient must wear a properly fitted surgical mask or valveless respirator 2
  • Return patient to isolation room as soon as practical 2
  • Ideally, treatment or radiology areas should have special ventilation for TB patients 2

Home Isolation

Patients may be discharged while still potentially infectious if:

• They will be isolated at home or in a facility with isolation capability 1
• No high-risk individuals (especially children under 4 years or immunocompromised persons) are in the household 1
• Patient agrees to:
  • Spend as much time as possible outdoors 1
  • Sleep alone in a separate, adequately ventilated room 1
  • Minimize time in congregate settings or public transport 1

Common Pitfalls to Avoid

1. Premature discontinuation of isolation due to:

   • Nonadherence to therapy
   • Presence of drug-resistant organisms 2, 1

2. Inadequate discharge planning leading to continued infectiousness 1

3. Failure to recognize drug resistance resulting in patients remaining infectious for months 1

4. Exposing immunocompromised individuals to TB patients:

   • More stringent isolation measures required when TB patients may expose HIV-positive or immunocompromised individuals 1
   • TB patients should not be seen in the same outpatient clinic as immunocompromised patients 1

5. Delaying isolation for patients with suspected TB:

   • Early identification and isolation is critical to prevent nosocomial transmission 2
   • Chest radiography showing cavities or apical/nodular infiltrates is highly suggestive of TB and should prompt immediate isolation 3