Pulmonary non-tuberculous mycobacterial infection

What it is

From: Orphanet

A rare bacterial infectious disease caused by non-tuberculous mycobacteria (including Mycobacterium avium complex, Mycobacterium kansasii, or Mycobacterium xenopi, among others), characterized by chronic pulmonary disease with symptoms like chronic cough (with or without sputum production), chest pain, and weight loss. Predisposing factors are preexisting lung conditions, neoplasms, immunosuppression, or thoracic skeletal abnormalities.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Cough · Very frequent (99-80%)

A sudden, audible expulsion of air from the lungs through a partially closed glottis, preceded by inhalation.

Nontuberculous mycobacterial pulmonary infection · Very frequent (99-80%)

An infection of the lung caused by environmental mycobacteria. Such infections can occur in individuals with predisposing lung disease or immune disease.

Productive cough · Very frequent (99-80%)

A cough that produces phlegm or mucus.

Asthenia · Frequent (79-30%)

A state characterized by a feeling of weakness and loss of strength leading to a generalized weakness of the body.

Bronchiectasis · Frequent (79-30%)

Persistent abnormal dilatation of the bronchi owing to localized and irreversible destruction and widening of the large airways.

Chest tightness · Frequent (79-30%)

An unpleasant sensation of tightness or pressure in the chest.

Chronic cough · Frequent (79-30%)

A persistent cough, defined as a cough lasting longer than eight weeks in adults or longer than four weeks in children.

Fatigue · Frequent (79-30%)

A subjective feeling of tiredness characterized by a lack of energy and motivation.

Hemoptysis · Frequent (79-30%)

Coughing up (expectoration) of blood or blood-streaked sputum from the larynx, trachea, bronchi, or lungs.

Immunodeficiency · Frequent (79-30%)

Failure of the immune system to protect the body adequately from infection, due to the absence or insufficiency of some component process or substance.

Increased sputum production · Frequent (79-30%)

An increase in the amount of airway mucus. This feature may be characterized by frequent or excessive throat clearing (exhalation through tightly constricted laryngopharyngeal tissues accompanied by vibration of the palatoglossal arch and the vocal folds serving to clear mucus from the airway).

Positive Mycobacterium avium sputum culture · Frequent (79-30%)

Growth of mycobacterium avium in a sputum culture.

Pulmonary cavity · Frequent (79-30%)

A gas-filled space, seen as lucency or low-attenuation area, within a nodule, mass or area of parenchymal consolidations. It has a clearly defined wall over 4 mm thick.

Pulmonary nodule · Frequent (79-30%)

Focal rounded or ovoid opacity, not more than 3 cm in diameter. Pulmonary nodules are typically observed by chest radiography or computer tomography imaging.

Other findings in the same source

From: Orphanet

Additional reported features include Pulmonary opacity (Frequent (79-30%)); Chest pain (Occasional (29-5%)); Chronic pulmonary obstruction (Occasional (29-5%)); Dyspnea (Occasional (29-5%)); Fever (Occasional (29-5%)); Mediastinal lymphadenopathy (Occasional (29-5%)); Night sweats (Occasional (29-5%)); Pleural effusion (Occasional (29-5%)); Weight loss (Occasional (29-5%)); Pneumothorax (Very rare (<4-1%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

All ages

Inheritance in the source

From: Orphanet

Not applicable

Frequency and the population described

From: Orphanet

Point prevalence: 1-9 / 100 000; Europe; Value and class.

Which doctor should you see?

The suggested department for discussing Pulmonary non-tuberculous mycobacterial infection is Infectious Diseases, with a general physician / infectious disease specialist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Which exposure or organism is suspected, and what evidence would confirm it?
• Are precautions, vaccination or advice for close contacts relevant to this infection?
• What should happen if symptoms worsen or do not improve as expected?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Pulmonary non-tuberculous mycobacterial infection. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.