Could it be Legionella?

BACKGROUND

Community acquired pneumonia is a common condition presenting to general practitioners and emergency departments across Australia. Legionella is one of many pathogens responsible for community acquired pneumonia. Cases of Legionella may occur sporadically or as part of an outbreak.

OBJECTIVE

This article describes the clinical manifestations of Legionella infection and provides clinicians with an approach to its diagnosis and management.

DISCUSSION

Legionella infection is typically associated with community acquired pneumonia, which can be severe. Features pointing to Legionella as a cause of pneumonia include the presence of gastrointestinal symptoms, especially diarrhoea; neurological symptoms, especially confusion; fever up to 40 degrees C; hyponatraemia; and hepatic dysfunction. However, none of these is required to make the diagnosis. Sometimes nonrespiratory symptoms can predominate. Diagnosis requires the use of special tests specific for Legionella, the most clinically useful being urinary antigen tests and serology. Recommended treatments include macrolide therapy or doxycycline.