If a patient was placed on TB precautions because of possible tuberculosis, then TB isolation can be discontinued if the diagnosis of tuberculosis can be ruled out and there is the presence of another diagnosis which can explain all of the clinical findings.
Patients with tuberculosis who are most likely to transmit infection are those:
(1) not receiving adequate treatment, AND
(2) have one or more of the following:
(2a) they have pulmonary or laryngeal tuberculosis and are coughing or undergoing a cough inducing procedure
(2b) have positive AFB sputum smear
(2c) have cavitation on a chest radiograph
(2d) have extrapulmonary focus of disease with a high concentration of AFB and with extensive drainage
If the diagnosis of tuberculosis cannot be ruled out, then the patient should remain in isolation until it has been determined that the patient is not infectious. Patients with suspected or confirmed active tuberculosis should be considered infectious if BOTH:
(1) they are coughing, undergoing cough inducing procedures or have positive AFB sputum smears, AND
(2) they are not on chemotherapy, have just started chemotherapy, have a poor clinical response to therapy, or have a poor bacteriologic response to therapy.
Indications for response to therapy:
(1) reduction in cough and sputum produced
(2) resolution of fever
(3) progressive decrease in quantity of AFB in smear
In general, isolation in a patient with tuberculosis should only be discontinued only when:
(1) the patient is on effective therapy
(2) the patient is clinically improving
(3) there have been at least 3 consecutive sputum AFB smears collected on different days
Hospitalized patients with known multidrug resistant isolates should be considered for continuous isolation due to risk of treatment failure or relapse.
Hospitalized patients with active tuberculosis should be monitored for relapse by having sputum AFB smears examined on a regular basis, such as every 2 weeks.
If a patient with tuberculosis is on apparently effective therapy and does not improve clinically, or shows relapse, then consider the possibility of:
(1) multi-drug resistant Mycobacterium tuberculosis
(2) nonadherence to therapeutic protocol
(3) another diagnosis
