What is the risk of bacterial meningitis in infants who present to the emergency department with fever and pyuria?

OBJECTIVE To determine the rate of bacterial meningitis among febrile infants in the emergency department (ED) who have pyuria detected in an initial catheterized urine specimen. METHODS This retrospective chart review, conducted at the Hospital for Sick Children, Toronto, Ont., involved all children aged 0 to 3 months who presented to the ED with fever and pyuria (>/=10 white blood cells/mm(3)) over a 3-year period. Cerebrospinal fluid (CSF) was evaluated using standard methods, and the rate of meningitis in children with pyuria was determined. RESULTS The study sample included 211 infants with fever and pyuria -- 79 of these under 1 month of age. Eighty-one percent (171/211) had positive urine cultures, and 143 underwent lumbar puncture to rule out meningitis. Of these, 140 CSF samples were culture negative and 3 grew coagulase negative Staphylococcus -- 2 because of contamination and 1 because of a ventriculo-peritoneal shunt infection. Both children with CSF contamination grew Escherichia coli in the urine. The rate of bacterial meningitis in the study sample was 0% (95% confidence interval, 0%-2.6%). CONCLUSIONS In this study of febrile children under 90 days of age with fever and pyuria, the incidence of concurrent meningitis was 0%. This suggests that recommendations for mandatory lumbar puncture in such children should be reconsidered. However, until larger prospective studies define a patient subset that does not require CSF analysis, it is prudent to rule out meningitis, administer parenteral antibiotics for urinary tract infection, and admit for close observation.