Definitions and Classifications (TB Status)


Pulmonary TB

An infectious respiratory disease caused Mycobacterium Tuberculosis with associating respiratory and systemic systems.

Extrapulmonary TB

TB of organs other than lungs (i.e., pleura, lymph nodes, abdomen, skin, joints, etc). Diagnosis is to be made via:

- Culture-positive specimen

- Histological evidence

- Strong clinical evidence consistent with active ETB

- Followed by full decision by a clinical to treat with a full course of anti-TB chemotherapy.

Latent TB

Defined as infection with Mycobacterium tuberculosis, where the bacteria may be alive but dormant in the asymptomatic patient. These patients should be diagnosed with ANY of the following:

- A normal or static in a period of 6 months in CXR finding. This includes healed lesions, nodular calcifications and well demarcated fibrotic lesions.

- Smear/culture negative on sputum or by bronchioalveolar lavage (if collected)

- Positive Mantoux test

New smear-positive PTB

A patient who has never been on any TB treatment, taken TB treatment for less than 30 days or who has the following

- Two or more initial sputum smear examinations positive for AFB

- One sputum examination positive for AFB plus radiographic abnormalities consistent with active TB as determined by a clinician

- One sputum specimen positive for AFB and at least one sputum specimen that is culture-positive for AFB.

New smear-negative PTB

A patient with PTB that does not meet the above criteria for smear-positive TB.

Previously treated

A case of PTB that has been treated, regardless of relapse, default or failure.


A patient who was previously classified to be “cured” or “treatment completed who is again diagnosed with culture positive or direct visualisation via microscopy with Mycobacterium tuberculosis.


A patient who is smear positive via sputum examination at ≥ 5 months during treatment process.


A patient who has interrupted treatment for two consecutive months or more


Former smear-positive who was smear-negative in the last month of treatment and on at least one previous occasion.

Completed treatment

A patient who has completed treatment but do not satisfy the criteria for cured or failure.


Known as Multi-drug resistant TB. Represent strains that are not responding to at least two first-line anti-TB drugs such as Isoniazid and Rifampicin.


After satisfying the definition of MDR-TB, XDR-TB cases are patients who are also resistant to fluoroquinolone and at least one of three injectable second-line drugs (capreomycin, kanamycin and amikacin)