USE OF URINARY GRAM STAIN FOR DETECTION OF URINARY-TRACT INFECTION ININFANTS

Study objective: To determine whether Gram stain of urine is more sens itive than urinalysis in detecting urinary tract infection in infants. Design: Prospective series. Setting: Urban teaching hospital emergenc y department. Participants: Two hundred seven infants 6 months old or less, from whom a catheterized or suprapublically aspirated urine spec imen was obtained for culture. Interventions: Urinary Gram stain, cult ure, and urinalysis were performed. With culture results as the valida ting standard, the Gram stain sensitivity, specificity, and predictive values were compared with urinalysis, including leukocyte esterase, n itrite, pyuria, and bacteriuria. Results: The prevalence of positive c ultures was 8.7% (18 of 207). Gram stain had higher sensitivity than o verall urinalysis (94% versus 67%, P<.05), higher specificity (92% ver sus 79%, P<.05), and higher positive predictive value (53% versus 23%, P<.05). Conclusion: Urinary Gram stain appears to be more reliable th an urinalysis in detecting urinary tract infection in young infants.