A urine culture must ALWAYS be interpreted in the context of the urinalysis and patient symptoms.
If a patient has no signs of infection on urinalysis, no symptoms of infection, but a positive urine culture, the patient by definition has asymptomatic bacteriuria, or the specimen was contaminated at the time of collection with organisms present on the skin/mucous membranes.
Typically, catheterized patients will become colonized within 48 hours of catheterization.
Patients with chronically indwelling catheters, urinary stoma, and neobladders will almost universally have positive urine cultures.
The only patient populations for which it is recommended to screen for and treat asymptomatic bacteriuria are pregnant women and patients scheduled for a genitourinary surgical procedure.
Patients without a Urinary Catheter
Patients WITH a Urinary Catheter
Pyuria and urinary catheters: Arch Int Med 2000;160(5):673-77.
IDSA Guidelines for treatment of uncomplicated acute bacterial cystitis and pyelonephritis in women: Clin Infect Dis 1999;29:745.
European and Asian guidelines on management and prevention of CA-UTI: Int J Antimicrob
Agents 2008; 31S:S68.