CJEM Articles: urinary tract infection
Displaying 1-2 of 2 results
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March
2007
9
2
James Ducharme, Jeffery L. Ginn, Shane Neilson
Objective: To compare the results of urine cultures and reagent strip testing in 2 groups of elderly emergency department (ED) patients: an asymptomatic group unlikely to have urinary tract infection (UTI), and a group who had vague symptoms and were considered at risk for UTI.
Methods: We performed a prospective observational convenience study with 2 groups of 100 patients aged 65 or older. The asymptomatic group consisted of afebrile patients presenting to the ED with non-infectious complaints, while the symptomatic group included patients presenting with acute confusion, weakness or fever but no apparent urinary symptoms. We defined a positive urine culture as a single organism count greater than 100 000 CFU/mL in mid-stream specimens, or greater than 1000 CFU/mL in catheter specimens. We considered reagent strips positive if they demonstrated any reaction to the leukocyte-esterase assay, the nitrite assay or both.
Results: Of the 33 positive cultures, 10 had negative reagent strips. Thirteen of the 14 positive nitrite tests were culture positive for a specificity of 92.8% and a sensitivity of 36.1%. Positive cultures did not infer a diagnosis of UTI. Of the 67 positive reagent strips, 41 (61.2%) were associated with negative cultures. Likelihood ratios (LRs) in both groups affirmed the inability of the reagent strips to help significantly in decision making, with positive and negative LR in the indeterminate range (control group: 2.8 and 0.31, symptomatic group: 2.7 and 0.46, respectively).
Conclusion: In the elderly, reagent testing is an unreliable method of identifying patients with positive blood cultures. Moreover, positive urine culture rates are only slightly higher in patients with vague symptoms attributable to UTI than they are in (asymptomatic) patients treated for non-urologic problems, which suggests that many positive cultures in elderly patients with non- focal systemic symptoms are false-positive tests reflecting asymptomatic bacteriuria and not UTIs. Blood cultures, regarded by many as the criterion standard for UTI, do not have sufficient specificity to confirm the diagnosis of UTI in elderly patients with non-specific symptoms.
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November
2003
5
6
Anne Matlow, Dennis Scolnik, Lauren Linett, Ran D. Goldman
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/mm3) 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.
