Nontuberculous Mycobacterial (NTM) Lung Disease: A Simple Explanation

Imagine tiny living things called bacteria. There are many different kinds, and some can make us sick if they get into our bodies.  

Nontuberculous mycobacteria (NTM) are a specific group of these bacteria.  

• "Nontuberculous" means they are NOT the same bacteria that cause tuberculosis (TB). While they are distant cousins in the same bacterial family, NTM bacteria behave differently and cause a different kind of illness. A key difference is that NTM lung disease is generally not contagious from person to person, unlike TB.  

• "Mycobacterial" just refers to the family name of these bacteria.

• "Lung Disease" means these particular NTM bacteria have infected the lungs and are causing problems there.

So, in simple terms, NTM lung disease is an infection in your lungs caused by a group of bacteria that are related to, but different from, the one that causes TB. You usually can't spread it to other people.  

Where do these NTM bacteria come from?

NTM bacteria are actually very common and are found naturally in the environment. You can find them in:  

• Water: Including tap water (especially in showerheads and hot tubs), natural bodies of water like lakes and streams.  

• Soil: Including potting soil.  

• Dust.

Most people breathe in or come into contact with NTM bacteria all the time and don't get sick. Our immune systems are usually good at fighting them off.  

Why do some people get NTM lung disease?

It's not always clear why some people develop NTM lung disease while others don't, even when exposed to the same bacteria. However, certain factors can make someone more likely to get it:

• Pre-existing lung conditions: People who already have lung problems like COPD (chronic obstructive pulmonary disease), emphysema, bronchiectasis (widened, damaged airways), or cystic fibrosis are more susceptible. The NTM bacteria can more easily take hold in lungs that are already damaged or don't clear mucus well.  

• Weakened immune systems: People with weakened immune systems due to conditions like HIV/AIDS, or those taking immune-suppressing medications (like for organ transplants or autoimmune diseases), are at higher risk.  

• Age: It's more common in older adults, particularly older women who are thin and may have a chronic cough.  

• Certain physical traits (less common): Some rare genetic conditions or physical abnormalities in the chest can increase risk.  

What happens when NTM bacteria infect the lungs?

When NTM bacteria settle in the lungs and start to multiply, they can cause inflammation and damage. This can lead to symptoms like:  

• A persistent cough (that may or may not bring up phlegm or mucus, sometimes even blood)  

• Fatigue (feeling very tired)  

• Shortness of breath

• Fever

• Night sweats

• Weight loss

• Chest pain

These symptoms can develop slowly over a long time and can sometimes be mistaken for other lung conditions.  

How is it treated?

Diagnosing NTM lung disease can sometimes be tricky and may involve chest X-rays or CT scans, and taking samples of lung mucus (sputum) to grow and identify the specific NTM bacteria.  

Treatment usually involves a long course of multiple antibiotics, often for a year or more. It's important to take all the medications as prescribed, even if you start to feel better, to fully get rid of the infection.  

In a nutshell: NTM lung disease is a lung infection caused by common environmental bacteria (not the TB bacteria) that most people fight off without issue. However, individuals with existing lung conditions or weakened immune systems are more vulnerable. It causes symptoms like a chronic cough and fatigue, and treatment involves a lengthy course of antibiotics. It's generally not spread from person to person.