Pulmonary Diseases Caused by Environmental Mycobacteria

Essentials

• Consider environmental (also "atypical" or "non-tuberculous") mycobacteria as causative agents in patients with
  • persistent pulmonary infection and chronic pulmonary disease or immunosuppression
  • undetermined prolonged pulmonary infections
  • suspected pulmonary tuberculosis that responds poorly to treatment.

Epidemiology

• The incidence of infections caused by environmental mycobacteria is increasing.
• The infection is acquired from water or soil, etc.
• Human-to-human transmission has not been reported.
• Development of a disease often requires an earlier damage to the lungs (e.g. earlier tuberculosis, pulmonary fibrosis, etc.)

Causative agent

• The following species cause pulmonary infections: M. avium-intracellulare, M. kansasi, M. xenopi, M. malmoense, M. scrofulaceum, M. simiae, M. szulgai, M. chelonei and M. fortuitum.

Symptoms

• Cough
• Sputum production
• Dyspnoea
• Weight loss
• Fever and bloody sputum are rare.

Investigations

Treatment

• The treatment is clearly more difficult than the treatment of ordinary tuberculosis.
• Treatment options include antituberculous medication, other antimicrobial drugs, and occasionally surgery.
• Eradication of the environmental mycobacteria is not always possible.
• Treatment is indicated if
  • there is growth in sputum culture samples repeatedly or in a single sample taken from a location that otherwise is sterile and
  • chest x-ray shows findings that match with an infection caused by environmental mycobacteria and
  • the patient has matching symptoms.
• If the patient has no or only minimal symptoms, follow-up without medication is in some cases a valid option.
• Treatment is started in specialized care.

Notification

• Follow the local regulation concerning notification of infectious diseases and reimbursement of treatment.