Catheter-associated urinary tract infection is rarely symptomatic: a prospective study of 1,497 catheterized patients.

BACKGROUND: Catheter-associated urinary tract infection (CAUTI) is the most common nosocomial infection, accounting for more than 1 million cases each year in US hospitals and nursing homes.

OBJECTIVE: To define the clinical features of CAUTI.

SETTING AND PATIENTS: A university hospital; 1,497 newly catheterized patients.

DESIGN: Every day that the catheter was in place, a quantitative urine culture and urine leukocyte count were obtained, and the patient was queried by a research worker regarding symptoms. To more precisely define the role of CAUTI in patients' symptoms, a subset of 1,034 patients, 89 of whom developed CAUTI with more than 10(3) colony-forming units per milliliter, who did not have another potentially confounding site of infection besides the urinary tract, was analyzed.

OUTCOME MEASURES: Presence of fever, symptoms commonly associated with community-acquired urinary tract infection, and peripheral leukocytosis.

RESULTS: There were 235 new cases of nosocomial CAUTI during the study period. More than 90% of the infected patients were asymptomatic; only 123 infections (52%) were detected by patients' physicians using the hospital laboratory. In the subset analysis, there were no significant differences between patients with and without CAUTI in signs or symptoms commonly associated with urinary tract infection-fever, dysuria, urgency, or flank pain-or in leukocytosis. Only 1 of the 235 episodes of CAUTI that were prospectively studied was unequivocally associated with secondary bloodstream infection.

CONCLUSIONS: Whereas CAUTIs are a major reservoir of antibiotic-resistant organisms in the hospital, they are rarely symptomatic and infrequently cause bloodstream infection. Symptoms referable to the urinary tract, fever, or peripheral leukocytosis have little predictive value for the diagnosis of CAUTI.