May be acquired from diverse environmental sources (e.g. tap water).
Bronchiectatics may be colonized (i.e. CF patients).
Must distinguish colonization from clinically significant infection.
Most common reason for isolation is colonization of the respiratory tract.
Most common true infections:
Blood stream infection (usually from vascular catheter)
Pneumonia
Other manifestations rare:
Endocarditis
Sinusitis
Cellulitis
May require contact precautions.
True pneumonia more likely in ICU and oncology patients, those with advanced age and after/during treatment with broad spectrum antimicrobial use.
