Bacteriology of Urinary Tract Infections in Emergency Patients Aged 0–36 Months

Abstract Background Because urinary tract infection (UTI) is the most frequent source of serious bacterial infections in young children, we studied the bacteriology of such infections in our institution. Objectives Pediatric urine cultures were reviewed for age- and sex-specific differences in testing, prevalence, causative organisms, and antibiotic sensitivities. Methods A retrospective 5-year observational study of all urine cultures from Emergency Department patients aged 0–36 months found 4403 cultures. Primary outcomes were numbers of cultures obtained, infections found, the organisms isolated, and their antibiotic sensitivities. Results Boys were cultured much less frequently (overall 4.7% vs. 19.4% of girls, p p  = 0.01), with more Gram-positive organisms (52.3%; vs. 18.6% Gram-positives in girls; p Conclusions Age- and sex-based assumptions guiding evaluation for and treatment of UTIs in young children should be reevaluated. We may not be culturing enough young boys, risking missed UTIs with potential for renal injury in this vulnerable group. Based on their significant rate of Gram-positive infections, those boys we treat empirically might benefit more from trimethoprim/sulfamethoxazole or amoxicillin/clavulanic acid than from third-generation cephalosporins. The persistence of positive cultures in 2-year-olds suggests we should be culturing beyond 24 months in both sexes. Urine Gram stains should be more frequently considered.