Nontuberculous Mycobacteria (NTM) Infections 



Mycobacterial species other than those belonging to the Mycobacterium tuberculosis complex and M. leprae



Found In:

 • Water/soil

 • Domestic and wild animals

 • Milk

 • Food products



Risk Factors For NTM Infections:

 • Immunocompromised status

 • Chronic lung disease

 • Postoperative status



NTM Cause Many Illnesses:

 • Pulmonary

 • Skin & Soft tissue

 • Lymphadenitis

 • Catheter related bloodstream infections

 • Disseminated infections



Lungs:

 • 90% of patient encounters due to NTM: Chronic lung infections

 • Nodular or cavitary lesions

	- Centrilobular nodules

	- Bronchiectasis

	- Tree-in-bud opacities



Lady Windermere Syndrome:

 • Syndrome of right middle lobe or lingular infiltrates. Noted in older women without predisposing lung disease, volume loss, adenopathy, or cavitation.



Slow Growers (Runyon Classification grp I-III):

Pulmonary:

 • MAC

 • M kansasii

 • M xenopi

 • M malmoense

Disseminated:

 • MAC

 • M kansasii

 • M haemophilum

 • M marinum

 • M genavense

Skin/Soft Tissue/Catheter:

 • MAC

 • M marinum

 • M haemophilum

Lymphadenitis:

 • MAC



Rapid Growers (Runyon Classification grp IV):

Pulmonary:

 • M abscessus

	- M. abscessus, M. chelonae, and M. fortuitum can produce lung disease, adenitis, skin and soft tissue infections, surgical site infections, and prosthetic device infections.

Disseminated:

 • M chelonae

 • M abscessus

 • M fortuitum

Skin/Soft Tissue/Catheter:

 • M abscessus

 • M chelonae

 • M fortuitum

 • M mucogenicum

Lymphadenitis:

 • M. abscessus

 • M. fortuitum

 • M. scrofulaceum

 • M. malmoense



NTM Pearls:

 • Corneal disease: M. chelonae

 • Healthcare/hygiene outbreaks: M. chelonae, M. fortuitum, M. abscessus

 • Line associated: M. mucogenicum

 • HIV: MAC, M. kansasii, M. genavense, M. haemophilum

 • Tropical setting: M. ulcerans (buruli ulcer)

 • M. gordonae - 99.9% a contaminant

 • NTM not communicable: Except M. massiliense in CF

 • Cross reacts with IGRAs: M. kansasii, M. marinarum, M. szulgai

 • M. fortuitum fish tank disease: Aspiration

 • M. marinum - fish/fish tanks

 • Footbaths: M. fortuitum or other RGM

 • Plastic surgery: M. chelonae/Other RGM

 • Cardiac surgery: M. chimaera



M. Kansasii:

 • Mimics TB with: Cavitary lung disease.

 • Predisposing conditions: Underlying lung disease, alcohol, cancer, and immunocompromised status.



M. Avium Complex (MAC):

 • Acquired from the environment

 • Municipal water sources may be an important source

 • MAC Encompasses:

	- M. avium

	- M. intracellulare

	- M. chimaera, M. colombiense, M. interjectum

	- M. timonense

	- M. bouchedurhonense, M. vulneris, and M. yongonense



Disseminated Disease:

 • Disseminated MAC disease may complicate MAC pulmonary disease through local multiplication and entry into the bloodstream - seeding of other organs and tissues.

 • Primarily occurs in severely immunocompromised patients such as:

	1. Advanced HIV (CD4 cell counts less than 50/μL)

	2. Hematologic malignancy

	3. History of immunosuppressive therapy including therapy with tumor necrosis alpha inhibitors

 • Presentation: Fever, night sweats, weight loss, and gastrointestinal symptoms (elevations of liver enzymes, diarrhea, abdominal pain, hepatomegaly.)

	- Bone Marrow - Anemia, neutropenia

	- Lymphoreticular - Adenopathy, Hepatosplenomegaly

	- Lung - Cough and lung infiltrates



NTM Pulmonary Disease:

Clinical Manifestations:

 • Fever (>80 percent),

 • Cough (productive or dry)

 • Night sweats (>35 percent)

 • Fatigue,

 • Malaise,

 • Weakness,

 • Dyspnea,

 • Chest discomfort,

 • +/- Hemoptysis.

 • Fever and weight loss occur less frequently than in patients with typical tuberculosis.



Diagnosis Of NTM Lung Disease:

 • Clinical (Symptoms, Imaging, high res CT)

 • Exclusion of other diagnosis

 • Microbiologic studies (Sputum, bronchial washings, Lung biopsy)



by Dr. Kushal Vaishnani @k_vaishnani and Ravi Singh @rav7ks



#Nontuberculous #Mycobacteria #NTM #Infections #differential #diagnosis #infectiousdiseases