ATS/IDSA Criteria (NTM Pulmonary Disease)

What the result means

Clinical

Pulmonary or systemic symptoms. The guideline marks the clinical and radiologic items as both required.

Radiologic

Nodular or cavitary opacities on chest radiograph, OR a high-resolution CT showing bronchiectasis with multiple small nodules.

Exclusion

Appropriate exclusion of other diagnoses.

Microbiologic

Any ONE of: two or more separate expectorated sputum cultures; one bronchial wash or lavage; or a lung biopsy with mycobacterial histology plus a positive culture.

One sputum is not enough

Two separate samples are needed, growing the SAME species or subspecies. These are environmental organisms and a single isolate is often contamination or transient colonisation.

One lavage IS enough

The two-sample rule applies to expectorated sputum only. Demanding two of a bronchial wash withholds a diagnosis the criteria grant.

Diagnosis is not treatment

The guideline states that making this diagnosis does not, in itself, require starting therapy. That turns on species, severity, progression and the patient.

If unmet

Patients suspected of the disease who do not meet the criteria should be followed until the diagnosis is firmly established or excluded.