Legionnaires

Background

• Notifiable, Severe pneumonia (10% fatality rate) caused by Legionella bacteria (L pneumophila.)
• Transmission via water aerosol
• Incubation 2 - 14 days
• Not transmitted from person-to-person

Clinical

• Moderate/severe pneumonia with Fever, delirium
• Diarrhoea, myalgia
• Impaired renal (hyponatraemia) and liver functions
• Pneumonia failing to respond to beta-lactams ± aminoglycosides

Risk factors:

• Age, male, smoking
• Chronic lung disease
• Immunodeficiencies (incl.diabetes)

Differential Dx

• Any severe community acquired or nosocomial pneumonia

Investigations

• Sputum C&S
• Urine: Ag detection
• Dx confirmed by culture or x4 rise in serum antibodies or detection of legionella DNA by PCR

Management

• Supportive care incl. early ventilation as required
• Beware occult dehydration and hypoperfusion
• Contact ID/respiratory team for advice about azothromycin, fluoroquinolones or macrolids
• Inform microbiology and public health of your working Dx

Links