Aerobic small Gram negative bacillus
Reservoir is water- aerosolization by cooling towers, spas, shower heads, etc.
Occurs in outbreaks
Person-to-person transmission not documented.
Pneumonia (Legionnaire's disease)
Pontiac fever is a self-limited febrile illness
Extrapulmonary infections rare, but include endocarditis
Urine Legionella antigen available. Only identifies L. pneumophila serotype 1 (~80% of all cases)
Specific microbiology set up needed to grow in culture, needs to be specifically requested (eg, bronchoscopy).
Can be identified by PCR of clinical samples-speak with medical microbiology.