Legionella is a significant cause of pneumonia and frequently causes severe disease. Owing to the association of Legionella with water and soil-borne outbreaks, detection of Legionella has implications for patient management and public health.
- Legionella is an important cause of severe pneumonia with significant mortality. Early appropriate antimicrobial therapy improves outcomes.
- Legionella has been associated with numerous outbreaks worldwide. Urgent notification to relevant public health departments in all Australian states and territories is required to allow rapid intervention by public health authorities.
- Risk factors for legionellosis include age 55 years or more, chronic lung disease, immunosuppression, smoking, recent travel and underlying medical conditions such as diabetes; however, legionellosis can occur in patients without apparent risk factors.
- Legionella pneumophila and L. longbeachae are the most commonly implicated causes of legionellosis in Australia.
- Rapid diagnosis of legionellosis can be made with urinary antigen and nucleic acid amplification testing on respiratory samples. Respiratory samples for culture are also important for diagnosis and epidemiological investigations.