Do patients on active tuberculosis (TB) medications require isolation?

Isolation Requirements for Patients on Active TB Medications

Patients on active TB medications DO require isolation initially, but isolation can be discontinued once they meet specific criteria: effective therapy with clinical improvement AND three consecutive negative sputum AFB smears collected on different days. 1

Initial Isolation Requirements

Patients with suspected or confirmed active pulmonary or laryngeal TB must be placed in airborne isolation immediately, regardless of whether treatment has been started. 1, 2 The key indicators that mandate isolation include:

• Presence of cough or undergoing cough-inducing procedures 1
• Positive AFB sputum smears 1, 2
• Not on chemotherapy, just started chemotherapy, or poor clinical/bacteriologic response to therapy 1, 2
• Cavitary TB on chest radiograph 2
• Laryngeal or extensive pulmonary involvement 1, 2

Criteria for Discontinuing Isolation

The time required for a TB patient to become noninfectious after starting anti-TB therapy varies considerably between patients. 1 Simply being on medications is NOT sufficient to discontinue isolation. 1

All Three Criteria Must Be Met:

1. Patient is on effective anti-TB therapy 1, 2
2. Clinical improvement is demonstrated (reduction in cough, resolution of fever, progressively decreasing quantity of bacilli on smear) 1
3. Three consecutive negative sputum AFB smears collected on different days 1, 2

Special Considerations

Multidrug-Resistant TB (MDR-TB)

Continued isolation throughout the entire hospitalization should be strongly considered for patients with MDR-TB due to the tendency for treatment failure or relapse, even when on appropriate therapy. 1 However, effective treatment can render even MDR-TB patients noninfectious when appropriate therapy is used. 3

Discharge Planning

Patients may be discharged home while still potentially infectious if appropriate arrangements are ensured. 1 This requires:

• All household members were previously infected OR no uninfected household members at very high risk (children <4 years, HIV-infected persons, severely immunocompromised individuals) 1
• Confirmed outpatient appointment with TB provider 1
• Sufficient medication supply until outpatient appointment 1
• Placement into case management or directly observed therapy (DOT) programs 1

Critical Pitfalls to Avoid

• Do NOT assume patients are noninfectious simply because they started treatment - some patients remain infectious for weeks or months, particularly with unrecognized drug-resistant TB. 1
• Do NOT prolong isolation unnecessarily once all three discontinuation criteria are met - this wastes resources and causes patient harm. 2, 3
• Do NOT discharge infectious patients to settings with susceptible contacts without proper arrangements. 1, 3
• Consider nonadherence to therapy and drug-resistant organisms if patients do not respond clinically within 2-3 weeks. 1

Pediatric Patients

Children with TB should be evaluated for infectiousness using the same parameters as adults. 1 Children who have typical primary tuberculous lesions without indicators of infectiousness (laryngeal/extensive pulmonary involvement, pronounced cough, positive AFB smears, cavitary TB) usually do not need isolation. 1