Think NTM? Test for NTM

Identify NTM sooner to help prevent the 
consequences of a delayed diagnosis1-3

If not diagnosed early enough and left unchecked, NTM can lead to decline of lung function, worsening symptoms, and a decrease in overall quality of life for patients.3-6

  • On average, it takes patients ~20 months from the first NTM-related symptom or diagnostic procedure to receive an NTM diagnosis7
  • Clinical, radiographic, and microbiologic criteria are all recommended by the ATS/IDSA Statement for diagnosing NTM lung disease6


Despite increasing prevalence, the index of suspicion for NTM lung disease remains low, making early diagnosis of NTM an ongoing challenge.8-10

It can often be missed due to its nonspecific or overlapping symptomatology in patients with underlying structural lung disease.9,11,12

These similarities in clinical presentation can result in NTM being undiagnosed or misdiagnosed.1-3,8,11

It may take on average 20 months from the first NTM-related symptom or diagnostic procedure to an accurate NTM diagnosis7

If not diagnosed early enough and left unchecked, NTM can lead to decline of lung function, worsening symptoms, and a decrease in overall quality of life for patients.3-6

Approximately 2/3 of NTM patients have moderate to severe NTM by the time they are diagnosed8,13

In some serious cases, delayed diagnosis may cause irreversible lung damage in more than half of undiagnosed patients.11,12

A delay in diagnosis may lead to inappropriate NTM management, which can result in antibiotic resistance3,14

  • Antibiotic monotherapy may be appropriate to treat an underlying lung condition, but it can induce antibiotic resistance in NTM patients14

Identifying NTM sooner can help accelerate treatment 
initiation and reduce the consequences of misdiagnosis1-3

ATS/IDSA Statement diagnostic criteria

The American Thoracic Society (ATS)/Infectious Diseases Society of America (IDSA) Statement diagnostic recommendations include*:

  • Bronchopulmonary symptoms, nodular or cavitary opacities on chest radiograph, or multifocal bronchiectasis with multiple small nodules on chest high-resolution computed tomography (HRCT) scan, and
  • Exclusion of other diagnoses
  • Positive culture results from at least 2 separate expectorated sputum samples, or
  • Positive culture result from at least 1 bronchial wash or lavage, or
  • Transbronchial or other lung biopsy with mycobacterial histopathologic features and positive culture for NTM or biopsy showing mycobacterial histopathologic features and 1 or more sputum or bronchial washings that are culture-positive for NTM

Proper testing procedures continue to evolve to meet the need for more rapid species identification and differentiation. Molecular methods, such as line probe hybridization, polymerase chain reaction-restriction fragment length, polymorphism analysis, and DNA sequencing, have become more popular than traditional biochemical tests or high performance liquid chromatography.6,15

It is strongly recommended to identify NTM isolates down to the species and subspecies level, and not just the group level (ie, Mycobacterium chelonae/abscessus group). Correct species- and subspecies-level identification is necessary to accurately assess the clinical significance and severity of isolates.6,16

For example, MAC can be classified into distinct species—including Mycobacterium avium and Mycobacterium intracellulare, which can be further divided into subspecies: avium, silvaticum, hominissuis, and paratuberculosis.17-19

Similarly, Mycobacterium abscessus can be differentiated by 3 subspecies: abscessus, massiliense, and bolletii, which are increasingly important to identify, as differing gene patterns can lead to different treatment outcomes.20

NTM and your practice

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Stay informed with updates about the latest research in NTM

NTM treatment decisions are often difficult and require experience managing the disease,6,15 which can mean a peer consultation or referral to a pulmonologist or ID specialist with experience in NTM may be necessary.6,12

To find a specialist with experience managing NTM 
locally, consider the following search tools:

The diagnosis and treatment strategies for pulmonary infections caused by NTM are summarized in the Statement by the American Thoracic Society (ATS) and the Infectious Diseases Society of America (IDSA). For the official ATS/IDSA Statement, please visit

The ATS/IDSA Statement was published in 2007 and is currently in revision.

*Adapted with permission from the American Thoracic Society. Copyright © 2015 American Thoracic Society. Griffith DE, et al; ATS Mycobacterial Diseases Subcommittee. Am J Respir Crit Care Med. 2007;175(4):367-416. The American Journal of Respiratory and Critical Care Medicine is an official journal of the American Thoracic Society.