Nontuberculous mycobacterial (NTM) lung disease is an rare infection caused by bacteria nontuberculous mycobacteria such as Mycobacterium avium complex.
These bacteria are common in the environment. They can be found in water, soil, and on both tame and wild animals. They are generally harmless but can sometimes cause lung damage when they enter your body. Everyone comes into contact with NTM bacteria.
Not everyone is at risk of getting NTM lung disease. However, people with underlying lung conditions like bronchiectasis, COPD, and asthma are at greater risk of getting infected. The disease is also common among those who are aged 65 and above.
Once infected, the disease can scar and damage your lungs over time. Treatment is not necessary in mild cases. Treatment may take as long as two years to clear up in severe cases.
NTM is characterized by symptoms such as coughing, shortness of breath, and fatigue. People can have the disease for months or even years without knowing because the symptoms are similar to other lung diseases.
Unlike tuberculosis (TB), you can’t get NTM from someone or pass it to others.
Causes and Risk factors of NTM lung disease
You can become infected if you consume food or water, or breathe in air that has been contaminated with the bacteria. The NTM bacteria finds its way to your lungs and causes an infection that inflames your airways.
There are more than 120 types of NTM capable of causing the infection. People often breathe or swallow these bacteria without falling sick. The reason for this is unknown.
You are more likely to get infected if you have any of these health conditions:
- Weakened immune system due to HIV or AIDS
- Previous tuberculosis infection
- Silicosis also known as Black lung disease
- Any disease that has causes extensive lung damage such as emphysema, chronic obstructive pulmonary disease (COPD), or bronchiectasis
- Lung transplant
- Acid reflux
- Cystic fibrosis
- Autoimmune disorders like Sjogren’s syndrome or rheumatoid arthritis
Risk factors of NTM lung disease include:
- Age: Older people tend to be infected with the disease
- Lifestyle: Smokers and former smokers are at risk of being infected
NTM bacteria are often found in warm, wet places like hot tubs, heated indoor pools, and steamy bathrooms. It is best to avoid hot tubs or indoor pools if you are at risk of being infected.
Signs and Symptoms of NTM lung disease
The severity of NTM differs from one person to another. Some people with the infection may experience no symptoms at all. For many people, the signs of the disease are similar to many other lung disorders.
This can pose a challenge, making it difficult to recognize NTM lung disease as something new and unique.
Symptoms of NTM lung disease include:
- Cough, sometimes with blood
- A large amount of mucus
- Night sweats
- Loss of appetite or weight
- Shortness of breath
Other symptoms of the infection include chest pain, wheezing, and chronic lung infections. Over time, lung function begins to deteriorate. There are two main types of NTM lung disease.
The less severe kind known as nodular bronchiectasis. This causes scarring in the airways, making it hard to cough up and clear out mucus. Older women are most at risk for this type.
A more severe form known as cavitary NTM lung disease causes scars, cavities, or pits in the lungs. This could lead to lung failure. However, NTM lung disease isn’t usually fatal.
A pulmonologist (lung doctor) can diagnose and confirm the disease and administer treatment.
A correct diagnosis of NTM may prove difficult and is often delayed due to its similarity to other lung diseases. This can be frustrating for patients and may worsen the condition and progressive lung damage.
To diagnose NTM lung disease, the doctor has to carry out tests to rule out the possibility of other lung infections and confirm that the patient is indeed infected with the NTM bacteria. The tests include:
- Clinical exam: This procedure involves enquiries about the patient’s medical history and physical exams to check breathing ability.
- CT-Scan or Chest X-ray: These are used to check for nodules, cavities or other changes in the lung tissue that would confirm NTM disease.
- Lab Culture: This procedure involves testing sputum samples, or fluid coughed up from the lungs for the NTM bacteria. This test is repeated several times on different days to confirm.
Treatment options for NTM lung disease depend on the severity of symptoms, type of bacteria causing the condition and health history. NTM can be challenging to eliminate. It is necessary to seek attention from a pulmonologist or infectious disease specialist for treatment.
Since treatment varies from one person to another, not everyone diagnosed with the disease needs to begin treatment immediately. Some infections occur slowly and may or may not progress. In cases like this, the doctor might recommend monitoring health before treatment.
Treatment begins immediately in severe cases. Treatment would include antibiotics taken for an extended period. The specific drug to be taken would depend on the type of bacteria responsible for the infection.
The progress of treatment will be monitored by collecting follow-up sputum samples. The disease will only be considered cured when samples show no sign of NTM infection for at least 12 months.
There are cases where surgery may be necessary. NTM lung disease caused by the bacteria, M. abscessus, is typically treated with surgery to remove the part of the lung that has been infected, followed by drug treatment.