What are the symptoms of Pulmonary Mycobacterium avium complex (MAC) infection?

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Last updated: June 16, 2025View editorial policy

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From the Guidelines

Pulmonary Mycobacterium avium complex (MAC) infection typically presents with symptoms such as cough, sputum production, fatigue, haemoptysis, and fever. These symptoms are based on a large retrospective case series involving patients on treatment for MAC-pulmonary disease, which found that almost all patients presented with cough, sputum production, and fatigue 1. The presence of fatigue, haemoptysis, and fever was also significantly correlated with semiquantitative culture results, indicating the severity of the disease. Some key symptoms of Pulmonary MAC infection include:

  • Persistent cough, often productive with sputum
  • Fatigue
  • Haemoptysis (coughing up blood)
  • Fever
  • Weight loss and decreased appetite may also be reported, although these are not as commonly highlighted in the literature as the primary respiratory symptoms. The severity of symptoms can vary widely among individuals, and some patients may experience severe respiratory compromise, especially if they have underlying lung conditions such as bronchiectasis, COPD, or prior tuberculosis 1. It's essential to consider MAC infection in patients with persistent respiratory symptoms that don't respond to standard treatments, especially in those with risk factors such as underlying lung disease or compromised immune systems.

From the Research

Symptoms of Pulmonary Mycobacterium avium complex (MAC) infection

  • Persistent cough and purulent sputum, usually without fever or weight loss 2
  • Slowly progressive nodular opacities on chest radiographs 2
  • Cavitary disease, although less common 2, 3
  • Bronchiectasis, particularly in middle-aged and elderly women 4
  • Progressive parenchymal lung disease 4
  • Symptoms can be indolent, leading to delayed diagnosis 2
  • Low body mass index, poor nutritional status, and extensive disease can be prognostic factors for disease progression 5
  • Positive acid-fast bacilli smear can also be a prognostic factor for disease progression 5

Patient Characteristics

  • Elderly women are more likely to be affected by Pulmonary MAC infection without predisposing conditions 2
  • Patients with underlying lung disease, immunosuppression, or certain chest wall abnormalities are also at risk 4
  • Patients with cystic fibrosis or an abnormal alpha(1)-antiproteinase gene may also be more likely to harbor MAC in their lungs 4

Treatment-Related Symptoms

  • Gastrointestinal adverse effects from treatment regimens, particularly with macrolides and rifamycins 6
  • Potential drug-drug interactions, such as rifamycin/protease inhibitor interactions in AIDS patients 6
  • Treatment-related adverse effects can be significant, leading to poor tolerance and treatment failure 6

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Treatment for Mycobacterium avium complex lung disease.

Journal of the Formosan Medical Association = Taiwan yi zhi, 2020

Research

Treatment of Mycobacterium avium Complex Pulmonary Disease.

Tuberculosis and respiratory diseases, 2019

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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