Signs and symtoms (fever with no other source is the most common; patient's may also have suprapubic or flank pain) AND pyuria (>5-10 WBC/hpf or >27 WBC/microliter) AND positive urine culture ≥100,000 colonies)
Patients with chronically indwelling catheters will almost universally have positive urine cultures.
Typically, catheterized patients will become colonized within 48 hrs of catheterization.
Stable patient, with no evidence of upper tract disease
Severely Ill, with evidence of upper tract disease, or hospitalized >48 hr