Sterile cerebrospinal fluid pleocytosis in young febrile infants with urinary tract infections.

OBJECTIVES: To determine the prevalence of and to identify risk factors for sterile cerebrospinal fluid (CSF) pleocytosis in a large sample of febrile young infants with urinary tract infections (UTIs) and to describe the clinical courses of those patients. DESIGN: Secondary analysis of a multicenter retrospective review. SETTING: Emergency departments of 20 North American hospitals. Patients Infants aged 29 to 60 days with temperatures of 38.0°C or higher and culture-proven UTIs who underwent a nontraumatic lumbar puncture from January 1, 1995, through May 31, 2006. MAIN EXPOSURE: Febrile UTI. OUTCOME MEASURES: Presence of sterile CSF pleocytosis defined as CSF white blood cell count of 10/µL or higher in the absence of bacterial meningitis and clinical course and treatment (ie, presence of adverse events, time to defervescence, duration of parenteral antibiotic treatment, and length of hospitalization). RESULTS: A total of 214 of 1190 infants had sterile CSF pleocytosis (18.0%; 95% confidence interval, 15.9%-20.3%). Only the peripheral white blood cell count was independently associated with sterile CSF pleocytosis, and patients with a peripheral white blood cell count of 15/µL or higher had twice the odds of having sterile CSF pleocytosis (odds ratio, 1.97; 95% confidence interval, 1.32-2.94; P = .001). In the subset of patients at very low risk for adverse events (ie, not clinically ill in the emergency department and without a high-risk medical history), patients with and without sterile CSF pleocytosis had similar clinical courses; however, patients with CSF pleocytosis had longer parenteral antibiotics courses (median length, 4 days [interquartile range, 3-6 days] vs 3 days [interquartile range, 3-5 days]) (P = .04). CONCLUSION: Sterile CSF pleocytosis occurs in 18% of young infants with UTIs. Patients with CSF pleocytosis at very low risk for adverse events may not require longer treatment with antibiotics.

Febrile infants with urinary tract infections at very low risk for adverse events and bacteremia.

BACKGROUND: There is limited evidence from which to derive guidelines for the management of febrile infants aged 29 to 60 days with urinary tract infections (UTIs). Most such infants are hospitalized for ≥48 hours. Our objective was to derive clinical prediction models to identify febrile infants with UTIs at very low risk of adverse events and bacteremia in a large sample of patients. METHODS: This study was a 20-center retrospective review of infants aged 29 to 60 days with temperatures of ≥38°C and culture-proven UTIs. We defined UTI by growth of ≥50,000 colony-forming units (CFU)/mL of a single pathogen or ≥10,000 CFU/mL in association with positive urinalyses. We defined adverse events as death, shock, bacterial meningitis, ICU admission need for ventilator support, or other substantial complications. We performed binary recursive partitioning analyses to derive prediction models. RESULTS: We analyzed 1895 patients. Adverse events occurred in 51 of 1842 (2.8% [95% confidence interval (CI): 2.1%-3.6%)] and bacteremia in 123 of 1877 (6.5% [95% CI: 5.5%-7.7%]). Patients were at very low risk for adverse events if not clinically ill on emergency department (ED) examination and did not have a high-risk past medical history (prediction model sensitivity: 98.0% [95% CI: 88.2%-99.9%]). Patients were at lower risk for bacteremia if they were not clinically ill on ED examination, did not have a high-risk past medical history, had a peripheral band count of <1250 cells per µL, and had a peripheral absolute neutrophil count of ≥1500 cells per µL (sensitivity 77.2% [95% CI: 68.6%-84.1%]). CONCLUSION: Brief hospitalization or outpatient management with close follow-up may be considered for infants with UTIs at very low risk of adverse events.