Nontuberculous Mycobacteria (NTM)


Nontuberculous mycobacteria (NTM) are environmental organisms that can be found in soil, dust, and water including natural water sources (such as lakes, rivers, and streams) and municipal water sources (such as water that people drink or shower in). NTM can also be present in healthcare facility water systems.  Infections may occur because of exposure to contaminated water. NTM cause infections involving the lungs (pulmonary NTM disease) and infections involving other body sites (extrapulmonary NTM disease). The majority of NTM infections are pulmonary, and result from inhaled airborne particles containing the organism, and primarily cause infection in individuals with underlying lung disease or who have weakened immune systems. Unlike Mycobacterium tuberculosis, pulmonary NTM infections are not typically transmitted person-to-person.

Extrapulmonary disease is less common and may result from the organism being introduced at the site of infection. A variety of infection types can occur, including skin and soft-tissue infections.

Both pulmonary and extrapulmonary NTM infections pose significant clinical and public health challenges. Infections due to these organisms are notoriously difficult to diagnose and treat. NTM species have varying antimicrobial susceptibility patterns and are often resistant to a wide array of commonly used antibiotics.


NTM infections are not nationally notifiable, and there are few population-based studies describing the epidemiology of NTM disease.  The Emerging Infections Program Healthcare-Associated Infections Community Interface (HAIC) NTM surveillance program was piloted 2019-2020, and has continued with ongoing surveillance in four EIP sites. Data from this project will inform policy and prevention strategies to reduce NTM infections.

Surveillance Objectives

  • Describe the epidemiology of pulmonary and extrapulmonary NTM infections
  • Describe microbiologic characteristics of public health relevance
  • Evaluate antimicrobial susceptibility of organisms causing NTM infections
  • Characterize the molecular epidemiology of NTM


Case Definition

Prevalent case: NTM identified from the same infection category (i.e., pulmonary or extrapulmonary) during the 12 months before the date of index specimen collection (DISC).

Incident case: no NTM were identified during the 12 months before the DISC.

Pulmonary Cases

Definitions for confirmed pulmonary cases are consistent with published guidelines (Treatment of Nontuberculous Mycobacterial Pulmonary Disease: An Official ATS/ERS/ESCMID/IDSA Clinical Practice Guideline | Clinical Infectious Diseases | Oxford Academic (

Possible case: NTM have been identified from a single sputum, tracheal or endotracheal specimen and no NTM were identified from pulmonary specimens during the 12 months before the DISC. Possible cases can become confirmed cases if NTM are identified in additional qualifying specimens and/or if the histopathological criterion is met, as outlined in the confirmed case definition below, in the 12 months after the DISC.

Confirmed case: the following microbiological criteria are met during the 12 months after the DISC.

Identification of NTM via culture or culture-independent test methods from:

  • At least two separate sputum (expectorated or induced), tracheal, or endotracheal specimens; or
  • One bronchial wash or bronchoalveolar lavage or lung tissue specimen;
    A lung biopsy specimen with histopathologic features (granulomatous inflammation or acid-fast bacilli) and identification of NTM via culture or culture-independent test methods from at least one pulmonary specimen.


The patient has not been reported as a pulmonary confirmed case, or had an “additional specimen” reported to HAIC NTM surveillance during the previous 12 months

Extrapulmonary Cases

Identification of NTM via culture or culture-independent test in any non-pulmonary body site, excluding stool or rectal swab specimens.


The patient has not been reported as an extrapulmonary confirmed case, or had an “additional specimen” reported to HAIC NTM surveillance during the previous 12 months.

Additional specimen: a specimen collected within 12 months following the DISC of a confirmed case, or after and within 12 months of another “additional specimen”

Case Ascertainment

The NTM surveillance program is an active population- and laboratory-based surveillance system. Surveillance staff regularly query local clinical laboratories for identification of NTM in a pulmonary or extrapulmonary specimen, among residents of a defined geographic area.

Excluded mycobacterial species are: M. gordonae, M. paragordonae, M. tuberculosis complex, M. leprae, M. lepromatosis, and M. ulcerans.

Surveillance Areas

Surveillance Areas
Site Estimated Population Under Surveillance: Pulmonary NTM Estimated Population Under Surveillance: Extrapulmonary NTM
Colorado (5 counties) 2,835,257* 2,835,257*
Minnesota (2 counties) 1,816,164* 1,816,164*
New York (2 counties) 1,047,276 1,047,276
Oregon (3 counties PNTM; statewide ENTM) 1,832,634 4,217,737*

*NTM reportable in the catchment area