Nontuberculous mycobacteria (NTM) are bacteria naturally found in soil, dust, and water that can cause infections in various parts of the body including lungs, blood, and skin. NTM infection can occur in anyone, but they are more often seen to appear in individuals with other health issues or weak immune systems. Let us read further to know more about NTM infection.
What Is NTM Infection?
Nontuberculous mycobacteria (NTM) are the bacteria that are related to the bacteria that cause tuberculosis, but they particularly do not cause tuberculosis. Although everyone breathes in NTM, only some people fall sick. People who have other health issues or a weakened immune system are likely to get sick from NTM.
More than approximately 200 types of NTM have been identified by now. NTM can cause infections in various parts of the body. These infections mostly affect the lungs, but they can also develop in other parts or organs of the body. Unlike other types of respiratory infections, NTM infections are rarely contagious.
Mild cases of NTM infections do not require treatments. However, chronic or severe infections can cause severe health issues like persistent cough and breathing problems; and individuals with these severe forms of NTM infections might need long-term treatments.
How Common Is NTM Infection?
NTM infections are turning out to be more common, especially among people who are 65 and above.(1) Rates of NTM infections seem to be increasing, especially among women and elderly citizens.(2)
These infections are increasing by 8% every year. In the U.S., around 75, 000 to 105, 000 individuals will be diagnosed every year.
Who Is at Risk for Contracting NTM Infection?
Although anyone can be infected with NTM, some groups of individuals are at higher risk than others. These groups include:
- People with damaged lungs from diseases, such as COPD, bronchiectasis, silicosis, cystic fibrosis, or any previous tuberculosis infection.
- Individuals with a weakened immune system, either due to rheumatoid arthritis or any autoimmune disorder, active HIV infection, or because of the immune-suppressing medications that people might be taking.
- People above 65 years old.
- Postmenopausal women.
Apart from these, some environments and behaviors are conducive to NTM exposure, which increases the risk for vulnerable individuals. NTM are present naturally in the soil, so any activity that stirs up dust and dirt increases the likelihood of breathing in these bacteria. Additionally, these organisms also thrive in water.
Causes of NTM Infection
People who are exposed to nontuberculous mycobacteria can get an NTM infection. However, not everyone who is exposed to the mycobacteria develops the infection. In many people, NTM infections develop after:
- Inhaling the mycobacteria from the environment.
- Being exposed to the mycobacteria from a medical device during any surgery.
- Drinking or bathing in water containing NTM.
Symptoms of NTM Infection
Symptoms of NTM infections vary depending on the severity of the infection. One might not experience any symptoms in case of a mild infection. However, in case of severe NTM lung infection, you might show symptoms like bad cough that does not go away or a cough that brings up blood. People also experience fatigue, fever, night sweats, and shortness of breath during physical activity. Some people with an NTM infection experience weight loss.
NTM skin infections might cause sores, rashes, or boils. If lymph nodes are also infected, swelling on those infected nodes could be noticed. This swelling or enlargement is known as lymphadenitis.
Diagnosis for NTM Infection
A doctor will perform a specific physical examination and know about your medical history. Then they might order certain laboratory tests, which include:(3)
Your doctor collects samples of your sputum, also known as mucus that is coughed up from the lungs, and the sample is then sent to the lab to look for the mycobacteria and also to grow the mycobacteria in culture. You might have to provide sputum samples for consequently several mornings.
In this type of lab test, your doctor inserts a device known as a bronchoscope through your nose or mouth into the lungs, which helps the doctor to see inside your airways.
NOTE: If your healthcare provider suspects an NTM infection in any other part of the body, you might have to undergo some other tests like blood culture and biopsy.
Treatments for NTM Infection
Treatment for NTM infection is quite complex and depends on the location of the infection and the type of species involved. This is because these infections can develop slowly, and your healthcare provide might not begin treatment immediately.
Antibiotics for NTM Infection in the Lungs
Antibiotics are mostly prescribed for treating NTM infections. Azithromycin, rifampin, and ethambutol are some antibiotics that might be prescribed by your doctor. Usually. For treating mycobacteria, healthcare providers often prescribe a combination of three types of antibiotics. One might have to take these antibiotics for twelve months or more to ensure that the infection is completely gone.
Surgery for NTM Infection Affecting Skin
For skin infections or other types of localized NTM infection, your doctor would prescribe surgery to remove damaged tissue along with antibiotic therapy.
In most cases, an improvement in symptoms can be expected during the treatment. However, relapses and incomplete resolution are also normal. Your doctor would closely monitor the treatment progress with regular follow-ups.
Prognosis of NTM Infection
The prognosis for individuals with NTM infections is mostly positive. However, it depends on the severity of the infection and the organ it has affected. Doctors can successfully treat NTM infections, depending on the site of infection and the type of NTM species.
However, it is also true that at times, treatments might not work and can lead to further complications. According to a review from 2022, the 5-year-all-cause mortality rate for individuals with lung disease from NTM ranges from 13% to 45%, which was double that of those who did not have an NTM infection.(4)
Recovery from NTM infection can take about twelve months or even more with antibiotic treatment. One should see their healthcare provider regularly during the treatment. You might feel exhausted and have a bad cough as you are recovering. Making lifestyle changes like improving nutrition and exercise can help ease these symptoms while recovering from an NTM infection.
NTM infections can also recur sometimes after ending your treatment. If you experiencing recurring symptoms of the infection, consider visiting your doctor immediately.
NTM infections are caused by nontuberculous mycobacteria, which are naturally found in soil and water. Although, anyone can get this infection, mostly people who have other health problems or a weakened immune system are more likely to be affected by the mycobacteria. Although NTM infections can be challenging to diagnose and treat, a cure is possible, especially in case of a prompt early diagnosis and effective treatment.
- NTM Infections on the Rise Nationally; Women and Elderly Most Affected (thoracic.org)
- Incidence and Prevalence of Nontuberculous Mycobacterial Lung Disease in a Large U.S. Managed Care Health Plan, 2008–2015 – PMC (nih.gov)