• Knowledge

    Non-tuberculous Mycobacteria (NTM)

    Occurrence, risks, and relevance for healthcare facilities

    Non-tuberculous mycobacteria (NTM) are environmental microorganisms that occur worldwide in water, soil, and dust. Although only a subset of these bacteria is considered pathogenic to humans, NTM represent a growing and increasingly relevant health risk, particularly in healthcare settings.

    NTM topics at a glance:

    What are non-tuberculous mycobacteria?

    Non-tuberculous mycobacteria, also referred to as atypical mycobacteria or MOTT (mycobacteria other than tuberculosis), are aerobic, non–spore-forming rod-shaped bacteria. A defining feature is their waxy, highly impermeable cell wall, which gives rise to a number of unique physical and chemical properties and contributes significantly to their environmental resilience.

    NTM species differ considerably with regard to:

    • virulence
    • growth rates
    • temperature and antibiotic sensitivity

    Clinically relevant NTM species

    The most frequently identified human pathogenic species include:

    • Mycobacterium avium und Mycobacterium intracellulare (Mycobacterium avium complex, MAC)
    • Mycobacterium kansasii
    • Mycobacterium xenopi
    • Mycobacterium abscessus

    Among these, MAC species have historically been the most clinically significant, predominating across disease categories and anatomical sites.

    They are currently divided into two groups: slow-growing mycobacteria (SGM) and rapid-growing mycobacteria (RGM).

    Distribution and epidemiology

    NTM are ubiquitous in the environment and have been detected in:

    • natural water sources and soil
    • drinking water systems
    • dust and aerosols
    • food products such as cheese and milk
    • fish tanks
    • metalworking fluids

    NTM epidemiology is dynamic and continues to evolve. Climatic factors, including rising temperatures and increased humidity, are thought to contribute to their spread. Studies from the United States indicate that warmer, more humid regions show a higher prevalence of NTM isolates than colder, drier areas.

    Relevance of drinking water systems

    Artificial water systems provide ideal conditions for NTM proliferation. In healthcare facilities, particular concern exists for:

    • water supply systems
    • dental units
    • reprocessing of medical devices, e.g., endoscopes
    • catheters, injection needles, surgical instruments, etc.

    Studies have shown that hospital water systems are frequently contaminated with mycobacteria, often at higher levels than those found in offices, hotels, or private residences.

    hospital-hygiene-infection-prevention-bg-centered

    Growth-promoting factors and biofilm formation

    The following conditions promote NTM growth:

    • water stagnation
    • insufficient hot water temperatures
    • biofilm formation

    Biofilms provide both nutrients and protection for microorganisms, making complete eradication of NTM from water systems particularly challenging.

    Resistance characteristics

    Non-tuberculous mycobacteria are inherently:

    • resistant to commonly used disinfectants such as chlorine
    • tolerant to elevated water temperatures
    • resistant to desiccation
    • often insensitive to many antibiotics

    These characteristics play a key role in their persistence within water-bearing systems.

    Transmission routes and infection risks

    Transmission to humans occurs almost exclusively via water, primarily through inhalation of contaminated aerosols.

    Special attention is required during the reprocessing of medical devices. In endoscopy, for example, microbiologically safe rinse water is essential to minimize infection risk.

    Diseases and clinical manifestations

    The incidence of NTM-related disease has increased steadily in recent years. While most infections do not result in illness in immunocompetent individuals, severe disease can occur in:

    • immunocompromised and immunosuppressed patients
    • elderly people
    • children
    • smokers
    • individuals with low body weight

    schwere Verläufe annehmen.

    Common disease manifestations include:

    • pulmonary infections
    • skin and soft tissue infections
    • disseminated disease

    Typical symptoms range from chronic cough, shortness of breath, weight loss, and fatigue to fever, skin lesions, lymphadenopathy, pain, and night sweats.

    Diagnosis and treatment

    Diagnosing NTM infections is complex. Microbiological detection and precise species identification are challenging and time-consuming, particularly for slow-growing organisms.

    There is no standardized treatment regimen. Therapy is species-specific and based on antibiotic susceptibility testing, often requiring prolonged combination therapy. Untreated infections may be fatal.

    Prevention and infection control

    Given the widespread presence of NTM in the environment, prevention remains a significant challenge. Experts recommend a coordinated, multi-layered approach, including:

    • strict hand hygiene
    • effective surface disinfection
    • terminal or inline Point-of-Use filters as an additional barrier

    At present, multi-barrier strategies represent the most effective means of reducing the risk of waterborne, healthcare-associated infections (HAIs).

    Hand hygiene and surface disinfection are under your control.
    To help minimize risks associated with water systems, we support you with Point-of-Use water filtration solutions, both terminal and inline.

    Learn more about “Infection Prevention & Water Hygiene” and discover our approach to responding proactively, reactively, and in acute emergencies.

    Switch to Hospital Hygiene & HAIs

    Your learning session on NTM bacteria

    Learn in a relaxing and easy way!

    In this animation, we have compiled interesting information about non-tuberculous mycobacteria in a clear and entertaining way.

    Our NTM film, creating awareness

    • Charles L. Daley, Jonathan M., Iaccarino Christoph Lange et al. Treatment of nontuberculous mycobacterial pulmonary disease: an official ATS/ERS/ESCMID/IDSA clinical practice guideline. European Respiratory Journal 2020 56(1): 2000535. DOI: https://doi.org/10.1183/13993003.00535-2020

      Prof. Dr. Dr. h.c. Christoph Lange. Internationale Empfehlungen für nicht-tuberkulöse Mykobakterien. DZIF – Deutsches Zentrum für Infektionsforschung. Pressemitteilung vom 7. Juli 2020. https://www.dzif.de/de/internationale-empfehlungen-fuer-nicht-tuberkuloese-mykobakterien

      Welte T, Dinkel J, Maurer F, Richter E, Rohde G, Schwarz C, Taube C, Diel R. Versorgung von Patienten/innen mit einer durch nichttuberkulöse Mykobakterien verursachten Lungenerkrankung in Deutschland – ein transsektorales patientenorientiertes Versorgungskonzept [Patients with lung disease caused by non-tuberculous mycobacteria in Germany: a trans-sectoral patient-oriented care concept]. Pneumologie. 2022 Aug;76(8):534-546. German. doi: 10.1055/a-1855-0858. Epub 2022 Jul 25. PMID: 35878604; PMCID: PMC9365527.

      Astrid Lewin, Hubert Schäfer. Fachgebiet 16: Erreger von Pilz- und Para­siten­infektionen und Myko­bakteriosen. Mykobakterielle Infektionen: Molekulare Charakterisierung der Erreger und die Immunantwort des Wirtes. Stand: 31.10.2022. Robert Koch-Institut. https://www.rki.de/DE/Institut/Organisation/Abteilungen/Abteilung-1/FG16/Mykobakterielle_Infektionen.html?templateQueryString=mykobakterielle+infektionen

      Anforderungen an die Hygiene bei der medizinischen Versorgung von immunsupprimierten Patienten. Empfehlung der Kommission für Krankenhaushygiene und Infektionsprävention beim Robert Koch-Institut (RKI) Requirements for hygiene in the medical care of immunocompromised pat[ients. Recommendations from the Committee for Hospital Hygiene and Infection Prevention at the Robert Koch Institute (RKI)]. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz. 2010 Mar 20;53(4):357–388. [Article in German] doi: 10.1007/s00103-010-1028-9 PMCID: PMC7095954 PMID: 20300719

      Yalan Gan, Iftita Rahmatika, Futoshi Kurisu, Hiroaki Furumai, Dai Simazaki, Hanako Fukano, Yoshihiko Hoshino, Ikuro Kasuga. The fate and risk of nontuberculous mycobacteria in the water supply system: a review. H2Open Journal (2022) 5 (2): 180–197. Volume 5, Issue 2. 1 June 2022. https://doi.org/10.2166/h2oj.2022.144

      Yun Shen, Sarah-Jane Haig, Aaron J Prussin II, John J LiPuma, Linsey C Marr, Lutgarde Raskin, Shower water contributes viable nontuberculous mycobacteria to indoor air, PNAS Nexus, Volume 1, Issue 5, November 2022, pgac145, https://doi.org/10.1093/pnasnexus/pgac145

      Trudy Li, Lydia S. Abebe, Ryan Cronk, Jamie Bartram. A systematic review of waterborne infections from nontuberculous mycobacteria in health care facility water systems. International Journal of Hygiene and Environmental Health. Volume 220, Issue 3, May 2017, Pages 611-620. https://doi.org/10.1016/j.ijheh.2016.12.002

      Grant J Norton, Myra Williams, Joseph O Falkinham III, Jennifer R Honda. Physical Measures to Reduce Exposure to Tap Water–Associated Nontuberculous Mycobacteria. Front Public Health. 2020 Jun 12;8:190. doi: 10.3389/fpubh.2020.00190 PMCID: PMC7304319 PMID: 32596197

      S.M. Blanc, D. Robinson, N.L. Fahrenfeld. Potential for nontuberculous mycobacteria proliferation in natural and engineered water systems due to climate change: A literature review. City and Environment Interactions, Volume 11, 2021, 100070, ISSN 2590-2520, https://doi.org/10.1016/j.cacint.2021.100070.

      Katherine Dowdell, Sarah-Jane Haig, Lindsay J Caverly, Yun Shen, John J LiPuma, Lutgarde Raskin. Nontuberculous mycobacteria in drinking water systems – the challenges of characterization and risk mitigation. Current Opinion in Biotechnology, Volume 57, 2019, Pages 127-136, ISSN 0958-1669, https://doi.org/10.1016/j.copbio.2019.03.010. (https://www.sciencedirect.com/science/article/pii/S0958166918302398)

      Katherine S. Dowdell, Sarah C. Potgieter, Kirk Olsen, Soojung Lee, Matthew Vedrin, Lindsay J. Caverly, John J. LiPuma, Lutgarde Raskin. Source-to-Tap Investigation of the Occurrence of Nontuberculous Mycobacteria in a Full-Scale Chloraminated Drinking Water System. bioRxiv 2024.04.18.590135; doi: https://doi.org/10.1101/2024.04.18.590135. published in Applied and Environmental Microbiology doi: 10.1128/aem.00609-24

      Lindsay A Hatzenbuehler, Melissa Tobin-D’Angelo, Cherie Drenzek, Gianna Peralta, Lisa C Cranmer, Evan J Anderson, Sarah S Milla, Shelly Abramowicz, Jumi Yi, Joseph Hilinski, Roy Rajan, Matthew K Whitley, Verlia Gower, Frank Berkowitz, Craig A Shapiro, Joseph K Williams, Paula Harmon, Andi L Shane, Pediatric Dental Clinic–Associated Outbreak of Mycobacterium abscessus Infection, Journal of the Pediatric Infectious Diseases Society, Volume 6, Issue 3, September 2017, Pages e116–e122, https://doi.org/10.1093/jpids/pix065

      Mark Levine, MD, Commissioner of Health. Outbreaks of Nontuberculous Mycobacteria Infections Highlight. Importance of Maintaining and Monitoring Dental Waterlines. Health Advisory. Vermont Department of Health. November 7, 2022. https://www.healthvermont.gov/sites/default/files/documents/pdf/HAN-dental-lines.pdf

      Lynch VD, Shaman J (2024) Hydrometeorology and geography affect hospitalizations for waterborne infectious diseases in the United States: A retrospective analysis. PLOS Water 3(8): e0000206. https://doi.org/10.1371/journal.pwat.0000206

      Dahl V, Pedersen A, Norman A, Rasmussen E, van Ingen J, Andersen A, et al. Clinical Significance, Species Distribution, and Temporal Trends of Nontuberculous Mycobacteria, Denmark, 1991–2022. Emerg Infect Dis. 2024;30(9):1755-1762. https://doi.org/10.3201/eid3009.240095

      L. Caverly, N. Kotlarz, M. Zimbric, J. Errickson, L. Raskin, J.J. LiPuma. Municipal Drinking Water Treatment Practices and Risk of Nontuberculous Mycobacterial Infection. American Journal of Respiratory and Critical Care Medicine 2018;197:A2604. https://www.atsjournals.org/doi/abs/10.1164/ajrccm-conference.2018.197.1_MeetingAbstracts.A2604?download=true

      Jasjit Singh, Kathleen O’Donnell, Delma J Nieves, Felice C Adler-Shohet, Antonio C Arrieta, Negar Ashouri, Gurpreet Ahuja, Michele Cheung, W Nathan Holmes, Kevin Huoh, Lisa Tran, M Tuan Tran, Nguyen Pham, Matthew Zahn. Invasive Mycobacterium abscessus Outbreak at a Pediatric Dental Clinic. Open Forum Infect Dis. 2021 Apr 15;8(6):ofab165. doi: 10.1093/ofid/ofab165. PMCID: PMC8186244 PMID: 34113683

      Edward A. Nardell. Nichttuberkulöse mykobakterielle Infektionen. msdmanuals.com. Überprüft/überarbeitet Juli 2022 | Geändert Sept. 2022. Abgerufen am 4. Dezember 2024, von https://www.msdmanuals.com/de/profi/infektionskrankheiten/mykobakterien/nichttuberkul%C3%B6se-mykobakterielle-infektionen

      Christina Selch, Dr. Frank Antwerpes et al. Nicht-tuberkulöses Mykobakterium. flexikon.doccheck.com. Abgerufen am 4. Dezember 2024, von https://flexikon.doccheck.com/de/Nicht-tuberkul%C3%B6ses_Mykobakterium

      Vanda Pinto, PhD. Metal in Source Water Tied to NTM Infection in Patients in Colorado. cysticfibrosisnewstoday.com. Published July 16, 2021. Abgerufen am 4. Dezember 2024, von https://cysticfibrosisnewstoday.com/news/molybdenum-source-water-metal-ntm-infection-colorado/

      Gesundheitsbibliothek bereitgestellt von der National Library of Medicine (NLM). Mykobakterielle Infektionen – Zusammenfassung. chcrr.org. Abgerufen am 4. Dezember 2024, von https://www.chcrr.org/de/health-topic/mycobacterial-infections/

      Dr. Manfred Fille. PneumoUpdate 2018: Atypische Mykobakteriosen: Was verstehen wir darunter und warum erkranken wir? universimed.com. Abgerufen am 4. Dezember 2024, von https://www.universimed.com/ch/article/pneumologie/atypische-mykobakteriosen-was-verstehen-wir-darunter-und-warum-erkranken-wir-2117811