Nontuberculous Mycobacteria Infections
What are nontuberculous mycobacteria (NTM) infections?
Nontuberculous mycobacteria (NTM) are bacteria naturally found in dust, soil and water. These organisms are related to the bacteria that cause tuberculosis, but NTM don’t cause tuberculosis.
Everyone breathes in NTM, but only some people get sick. You’re most likely to get sick from NTM if you have other health problems or a weakened immune system. There are more than approximately 200 types of NTM mycobacteria identified. Most of the pulmonary (lung) NTM infections in the U.S. are caused by the most common type, Mycobacterium avium complex (or MAC).
NTM can cause infections in different parts of the body. These infections occur most often in the lungs, but can also develop in other organs. It’s rarely contagious, meaning that NTM infections are not spread from person to person, unlike other types of respiratory infections.
NTM infections have been identified in healthcare settings, such as hospitals. The bacteria have been associated with catheter-associated bloodstream infections and other device- and water-related infections.
If you have a mild NTM infection, you may not need treatment. Severe infections cause chronic (long-term) health problems such as persistent cough and breathing problems that can affect your quality of life. People with these infections may need ongoing treatment for years. NTM infections can be localized (limited to one part of the body) or disseminated (spread throughout the body).
Who might get nontuberculous mycobacteria (NTM) infections?
Anyone can get NTM infections, but they are more likely to affect people with:
- Gastroesophageal reflux disease.
- Lung disease, including emphysema, cystic fibrosis, chronic obstructive pulmonary disease (COPD), asthma and bronchiectasis.
- Weak immune systems, including people who take immunosuppressant drugs for medical reasons and the elderly.
- Genetic conditions.
- With pectus excavatum, scoliosis or mitral valve prolapse (for those who develop pulmonary MAC), along with being a tall, slender elderly female.
Symptoms and Causes
What causes nontuberculous mycobacteria (NTM) infections?
People can get an NTM infection after exposure to nontuberculous mycobacteria. Not everyone who encounters the mycobacteria develops an infection.
NTM infections can affect different parts of your body. Most NTM infections happen in the lungs. These infections are also called NTM lung disease. NTM infections can also develop in your:
- Lymph nodes (sometimes called lymph glands).
- Skin and soft tissue (skin nodules, or infections in surgical incisions after an operation).
In many people, NTM infections develop after:
- Drinking, bathing or showering in water containing NTM.
- Inhaling the mycobacteria from the environment.
- Exposure to the mycobacteria from a medical device during surgery.
What are the symptoms of nontuberculous mycobacteria (NTM) infections?
Symptoms of an NTM infection depend on the severity of the infection. If you have a mild infection, you may not have any symptoms. If you have NTM lung infection, it may feel like a case of bronchitis that won’t go away.
Depending on what part of your body the infection affects, you could have signs and symptoms of an NTM infection such as:
- Cough that doesn’t go away, or cough that brings up blood (hemoptysis).
- Fatigue (extreme tiredness).
- Fever and night sweats.
- Shortness of breath during activity.
- Weight loss.
NTM infections in the skin might cause sores, boils or rashes. If lymph nodes get infected, you might have swelling in those nodes. This enlargement is called lymphadenitis.
Diagnosis and Tests
How are nontuberculous mycobacteria (NTM) infections diagnosed?
A doctor tests you for an NTM infection. Symptoms of NTM infections are similar to other conditions such as pneumonia. Your doctor may use several tests to rule out these conditions and confirm that nontuberculous mycobacteria are present.
If your doctor suspects a lung infection, tests to confirm the diagnosis may include:
- Sputum culture: Your doctor collects samples of sputum (mucus coughed up from the lungs) and is then sent to the laboratory to look for the mycobacteria under the microscope and also to grow the mycobacteria in culture. Your doctor may ask you to provide sputum samples several mornings in a row.
- Bronchoscopy: A doctor inserts a device called a bronchoscope through your nose or mouth into your lungs. The scope lets your doctor see inside your airways.
- Imaging tests: Tests such as X-rays and CT scans help doctors confirm signs of NTM.
If your doctor suspects an NTM infection in another part of the body, you may have tests such as:
- Blood culture: A sample of your blood is cultured to see if NTM are present.
- Biopsy: Your doctor removes a small sample of tissue and studies it under a microscope for mycobacteria, and to also grow it in culture from the tissue sample.
Management and Treatment
How are nontuberculous mycobacteria (NTM) infections managed or treated?
Treatment for NTM infection depends on the location of the infection and the species (type) of mycobacteria involved. Because these infections can develop slowly, your doctor may not begin treatment right away.
To treat NTM infection, your doctor will give you drugs called antibiotics such as azithromycin, ethambutol and rifampin. Doctors often prescribe a combination of three types of antibiotics to treat the mycobacteria. You may need to take these drugs for 12 months or more to make sure the infection is completely gone.
In the U.S., the first and only FDA-approved medication to specifically treat MAC lung disease as part of the antibiotic combination therapy is amikacin liposome inhalation suspension (ARIKAYCE®). A few potential side effects include voice issues, hypersensitivity pneumonitis, and bronchospasm.
For skin infections or some other types of localized NTM infection, your healthcare provider might remove damaged tissue surgically, in addition to antibiotic therapy.
What are the complications of nontuberculous mycobacteria (NTM) infections or their treatment?
The drugs used to treat NTM infections can have unpleasant side effects including nausea and vomiting. Tell your healthcare provider if you experience these side effects. Your provider can help ease the effects by changing the amount or type of medication you take.
If the bronchial tubes are damaged by an NTM infection, you may end up with the condition called bronchiectasis. The widening of the tubes leads to increased mucus which can breed bacteria and lead to increased risk of infections.
How can you prevent nontuberculous mycobacteria (NTM) infections?
If you have lung disease or a weak immune system, you can reduce your risk of NTM infections by limiting your exposure to environments containing the bacteria. These areas may include:
- Hot tubs, particularly in areas that are enclosed.
- Showers and sink sprayers that produce a fine mist you can inhale.
- Soil (especially potting soil).
Outlook / Prognosis
What is the prognosis (outlook) for people with nontuberculous mycobacteria (NTM) infections?
Healthcare providers can successfully treat NTM infections, depending on the site of infection and the type of NTM species. Recovery can take 12 months or more with antibiotic treatment. It’s important to see your provider regularly during treatment.
As you’re recovering, you may feel tired and have a cough that does not go away. Making lifestyle changes like exercising and improving your nutrition can help ease these symptoms. If you feel better, you can still live a fulfilling life during treatment.
Sometimes, NTM infections recur (happen again after successful treatment). If you experience symptoms of NTM infection after ending your treatment, contact your healthcare provider right away. Getting treatment quickly can help keep the infection from getting worse.
When should you call your healthcare provider if you are concerned about NTM infections?
Contact your provider if you experience pneumonia-like symptoms including cough, sputum production, fatigue and fever. Tell your healthcare provider if these symptoms don’t get better after treatment for pneumonia, or if you have recurrent episodes of pneumonia. You should also consult your healthcare provider right away if you are coughing up blood or have unexplained shortness of breath.
What questions should you ask your healthcare provider if you have a nontuberculous mycobacteria (NTM) infection?
If you have NTM infection, you may want to ask:
- How serious is the infection?
- What drugs should I take and how long will I take them?
- What are the side effects of the medications and how do we monitor them?
- What signs of complications should I look out for?
- How can I avoid becoming infected again?
- In addition to taking the suggested medication, what else can I do to get better?
Are there resources for people with NTM infections?
This list is not meant to be complete. However, you might find these organizations to be helpful.
- American Lung Association
- Bronchiectasis and NTM Initiative https://www.bronchiectasisandntminitiative.org/BronchandNTM360social/Community-Discussions/Activity-Feed
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