Nontuberculous mycobacterial infections

Nontuberculous mycobacterial infections include healthcare-related infections occurring after tap water contamination. Exposures have occurred in surgery (cardiac, plastic, and LASIK) and from injections, dialysis, central intravenous catheters, tympanostomy tubes, and foot baths in nail salons.

12,300 (US); 246,000 (Global)
Nontuberculous mycobacteria; NTM; Mycobacteria other than tuberculosis; MOTT; Environmental mycobacteria ; Mycobacterium avium complex (M. avium & M. intracellulare); MAC; MAI; M. kansasii; M. haemophilum; M. chelonae; M. scrofulaceum; M. xenopi; M. simiae; M. fortuitum; M. chelonae; M. abscessus; M. malmoense; M. celatum; M. genavense; M. gordonae;
10-21 days for MAC to grow on solid media; [ABX Guide: M. avium-complex]
Skin ulcers; Post-surgical infections; Nontender, unilateral cervical adenitis; Pulmonary symptoms; Disseminated (CD4+ counts < 50 T cells/ul): fever, night sweats, weight loss, abdominal pain, diarrhea, hepatosplenomegaly & anemia; [ATS/IDSA Statement]
Pulmonary or Wound: Standard; "Not transmitted person-to-person." [CDC 2007 Guideline for Isolation Precautions]
1. Skin, soft tissue & bone disease: M. ulcerans (See Buruli ulcer.); M. marinum (See Mycobacterial marinum infections.); M. abscessus; M. chelonae; M. fortuitum;
2. Lymphadenitis: M. avium complex (MAC); M. scrofulaceum; M. malmoense; See "Lymphadenopathy."
3. Pulmonary disease similar to TB: MAC; M. kansasii; M. abscessus; M. xenopi; M. fortuitum; and M. malmoense;
4. Hypersensitivity: MAC; M. immunogenum; (See Hypersensitivity Pneumonitis.)
5. Disseminated disease: MAC; M. kansasii, M. haemophilum, and M. chelonae;

More than 125 NTM species are now recognized. Most state public health labs now process more NTM than TB specimens. Healthcare-related infections occur after tap water contamination. Exposures have occurred in cardiac surgery, plastic surgery, and LASIK eye surgery and from injections (multidose vials), dialysis, central intravenous catheters, middle ear tympanostomy tubes, and foot baths in nail salons. Person-to-person transmission does not occur. "Bronchiectasis and NTM infection, usually MAC, often coexist, making causality difficult to determine." "NTM species that are generally not pathogenic and usually isolated due to contamination when recovered from respiratory specimens include M. gordonae, M. terrae complex, M. mucogenicum, and M. scrofulaceum." [ATS/IDSA Statement: Nontuberculous Mycobacterial Diseases] Mycobacteria are not identified by routine microbiological testing. Two broad categories of NTM are rapidly growing (<7days) and slowly growing (>7 days). The main NTM in North America are Mycobacterium avium complex (MAC), M. kansasii, and M. abscessus. Disseminated disease due to MAC infection in AIDS patients is now uncommon in North America because of MAC prophylaxis and improved treatment of HIV infection. [Cecil, p. 2010-11] Disseminated disease is rare. Pulmonary disease is most common in industrialized countries. Cervical lymphadenopathy, usually caused by MAC organisms, is the most common site in children in North America. Soft tissue infections usually follow a break in the skin, e.g., pedicure bath infections after leg shaving (M. fortuitum) and painful, red, draining subcutaneous nodules from contaminated surgical instruments (rapidly growing NTM). [Harrisons, p. 513-4] "MAC infection most commonly develops during the sixth or seventh decade of life in women who have had months or years of nagging intermittent cough and fatigue, with or without sputum production or chest pain." [Harrison ID, p. 645]

"Two major disease syndromes are produced by MAC in humans: (1) pulmonary disease, usually in adults with some underlying lung disease but whose systemic immunity is generally intact; and (2) extrapulmonary disease, most commonly disseminated disease in patients with advanced immunosuppression such as human immunodeficiency virus (HIV) infection, or localized cervical lymphadenitis, usually in immunocompetent children" [PPID, p. 3035-6] M. chelonae can cause keratitis related to contact lens use and ocular surgery (post-LASIK). [Cohen, p. 155-6] Pleural effusion is rare. [Merck Manual, p. 1661] Mediastinal lymphadenopathy and pleural effusion are very uncommon. [Cohen, 3rd Ed, p. 325]
Criteria for NTM lung disease: Multifocal bronchiectasis with multiple small nodules on CT if no cavitation on chest x-ray; AND exclude TB; AND 2 + sputum cultures; OR 1 + BAL culture; OR 1 biopsy with + histology/+ AFB and + culture; [ATS/IDSA Statement]
Global; M. ulcerans causes Buruli ulcer in tropical areas of Australia, Africa, and Southeast Asia, but not in the U.S. M. abscessus is endemic to southeastern USA (Florida & Texas);
  • >fatigue, weakness
  • >fever
  • G abdominal pain
  • G diarrhea
  • G hepatomegaly
  • H anemia
  • H lymphadenopathy
  • H splenomegaly
  • H thrombocytopenia
  • R chest pain
  • R cough
  • R dyspnea
  • R hemoptysis
  • R sputum production
  • S lymphadenitis, acute
  • S lymphangitis
  • S nodular lymphangitis
  • S papules or plaques
  • S pustule
  • S skin or subcutaneous nodule
  • S ulcer of skin
  • X cystic or cavitary lesions
  • X hilar lymphadenopathy
  • X lung infiltrates
  • X pleural effusions
  • *arthritis
  • *blindness
  • *endocarditis
  • *mediastinitis
  • *meningitis
  • *osteomyelitis
  • *pericarditis
  • *pneumonia
  • *pneumonitis
  • *uveitis
  • *weight loss




Inhalation, Needle (Includes Drug Abuse), Scalpel or Transfusion, Skin or Mucous Membranes (Includes Conjunctiva)
Soil or Dust (Ingesting or Inhaling), Eating Unpasteurized Milk or Cheese, Waterborne (Ingesting, Inhaling, or Swimming)
  • AIDS patients
  • Cancer patients
  • Inhale bioaerosols indoors
  • Injection drug users
See ABX Guide for treatment of the following: M. abscessus; M. avium-intracellulare; M. chelonae; M. fortuitum; M. kansasii; and M. marinum;
1. (US) Prevalence estimated at 5-19 cases/100,000 of MAK pulmonary disease; [PPID, p. 3036] 300 cases per year of MAC lymphadenitis; Prevalence of 1-7.2 cases/100,000 cases (atypical mycobacteria) in the US; [Gorbach, p. 82] Estimate: Use 4.1 (average of 1-7.2); 4.1 X 3000 = 12,300;
2. (Global) Estimate global cases/yr at 20 X US cases/yr;