Introduction
Nontuberculous mycobacterium is a common microorganism found in soil and water in many parts of the world. Everyone might be exposed to the bacteria at one point or another. They are thought to be less virulent (the ability of a pathogen to destroy the host) than Mycobacterium tuberculosis (the micro-organism responsible for tuberculosis). However, it only causes diseases in people with a weak immune system or an existing lung condition. The micro-organism is generally not transmitted from one person to another.
What Is Nontuberculous Mycobacteria?
There are a number of names for Nontuberculous mycobacteria are better known, which include environmental mycobacteria, atypical mycobacteria or anonymous mycobacteria, mycobacteria other than Mycobacterium tuberculosis (MOTT) and its close relatives. These micro-organisms are broadly found throughout the environment in milk, food products, plants, soil, dust, and natural and drinking water sources. They are characterized by a thick outer coating rich in lipids and encircled by a thin peptidoglycan layer. It is this coating that allows the bacteria to stick to rough surfaces and provide resistance to antibiotics and disinfectants. In addition, they help the micro-organisms to survive in low-oxygen or carbon dioxide areas or similar adverse places. Based on their growth capacity, Nontuberculous mycobacteria are classified as slow-growing and rapidly-growing mycobacteria. Slow-growing bacteria grow within seven days, while the rapidly growing strain grows in five days.
What Are Nontuberculous Mycobacteria (NTM) Infections?
Any infections that are caused by bacteria belonging to the genus Mycobacterium. The most common part of the body that gets affected is the lungs. The other areas include blood, bones, lymph nodes, skin, and other soft tissues. They can either be localized to one part of the body or spread to other parts. However, infections in other body parts other than the lungs are rare among those with a healthy immune system.
What Are the Symptoms of Nontuberculous Mycobacteria Infections?
The symptoms of Nontuberculous mycobacterial infections can include:
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Fever.
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Fatigue or weakness.
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Weightloss.
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Swollen lymph nodes.
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Night sweats.
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Reduced appetite.
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Cough.
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Shortness of breath.
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Blood in sputum.
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Rashes.
The symptoms of the infection can also depend on the site of infection. Pain, redness, swelling, sores, ulcers, or rashes are seen when the skin is affected. If the musculoskeletal system is affected, joint pain and stiffness can be the signs commonly seen. Cough with or without blood and shortness of breath are seen when the lungs are affected.
How Is the Infection Spread?
As said before, the bacteria is found in the environment. It can be spread through:
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Drinking, showering, or bathing in water contaminated with the pathogen.
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Inhaling the bacteria from the environment (people with an existing lung condition are easily affected by this).
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Surgical tools or medical devices like central venous lines.
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Contaminated needles.
NTM infections are non-contagious and rarely spread from one person to another. The symptoms of the infection are not visible as soon as someone is infected. Hence, one might not even know they are infected.
What Are the Risk Factors for the Infection?
Not all people who come in contact with the micro-organisms need to be affected. However, some people who have a higher risk of contracting the infection can include:
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Those infected with HIV (Human Immunodeficiency Virus).
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Cancer patients and other people with weak immunity.
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Those under immunosuppressive drugs, like after an organ transplant.
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Those having an underlying condition like cystic fibrosis (a genetic condition that affects the lungs and digestive system), bronchiectasis (a condition where the airways of the lungs become damaged), asthma (chronic inflammation of the airways of the lungs), or emphysema (a condition that affects the alveoli of the lungs).
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Those who have a central venous line, breathing tube, feeding tube, or another surgical device that is inside the body.
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Those who are female assigned at birth, and women with a low body mass index (BMI) and certain health conditions, like GERD (chronic acid reflux), scoliosis (a condition where the spine has curvature), pectus excavatum (an abnormality of the breastbone), or mitral valve prolapse (a condition where the valves of the upper and lower chambers are affected), are at an increased risk.
How Is the Infection Diagnosed?
The condition might take time to be diagnosed, as the symptoms might not be seen at the time of infection. A detailed medical history might point out evidence of the infection. The other tests done can include:
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Testing the phlegm samples.
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Testing the blood, sputum, or urine samples.
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Imaging tests like X-ray or CT (computerized tomography) scan.
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Lung function tests.
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Bronchoscopy.
What Are the Complications of NTM Infection?
The complications of the condition can include:
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Lung cavities.
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Abscesses in the lung.
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Skin scars.
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Respiratory failure.
What Are the Differential Diagnosis for NTM Infection?
The condition must be ruled out for other differential diagnosis, which can include:
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Tuberculosis.
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Recurrent pulmonary aspirations.
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Pneumonitis.
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Bronchiectasis.
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Histoplasmosis.
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Aspergillosis.
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Lung cancer.
How Is the Infection Treated?
NTM may share the symptoms with other infections. Hence, the right diagnosis is essential to treat the condition appropriately. The treatment of the condition is complex and can last long. Healthcare professionals might use a combination of antibiotics for treatment. The commonly used antibiotics include Clarithromycin, Ethambutol, and Amikacin liposome suspension for inhalation (ALIS). The medication may last for a long period to eradicate the infection. Severe cases might require surgery to remove the diseased tissue. Other treatments can include breathing exercises that enable coughing and spitting of the sputum, which may contain bacteria.
A combination of two drugs is required, even in a limited skin or soft tissue infection. A susceptibility test helps to understand what drugs should be combined and at what dosage. The severity of the condition may determine the number of antibiotics required.
Conclusion
A lung infection or a compromised immune system can increase a person’s risk of contracting a Nontuberculous mycobacterial infection. Avoiding anything that increases the risk of the infection is recommended. This can include the use of hot tubs, especially those in closed spaces, using spray mists that might cause the fumes to be inhaled, getting a tattoo done, or even working with or in the soil. The earlier the condition is suspected, the earlier it is to be treated. The prognosis of the condition depends on the causative agent, the area affected, and the co-morbidities of the patient.
