Use of rapid dipstick tests to exclude urinary tract infection in children.

Children presenting with symptoms attributable to urinary tract infection (UTI) are not uncommonly referred to paediatric departments for assessment. The aim of this study was to evaluate the use of rapid dipstick tests in the diagnosis of urinary tract infection in children. Urine was collected from 375 children admitted to a general paediatric ward, in whom UTI was a possibility on clinical grounds. Of these, 124 were less than one year old. Urine was tested with a dipstick for the presence of nitrite and leucocyte esterase. Bacterial culture and examination for white cells, red cells and other formed elements were performed. The results of the dipstick tests, microscopy and culture were correlated with the clinical details. Combination of a negative dipstick test for nitrite and leucocyte esterase showed a negative predictive value for UTI of 96.9% and a specificity of 98.7%. In children less than a year old these values were 96.7% and 99.2% respectively. The leucocyte esterase strip test showed a negative predictive value for pyuria of 94.3% with a specificity of 86.9%. In children less than a year old these values were 93.1% and 84.4% respectively. The use of dipsticks for the detection of urinary nitrate and leucocyte esterase in daily clinical practice is recommended. In children, the absence of both nitrite and leucocyte esterase in urine indicates that UTI is unlikely; however, positive dipstick tests for nitrite and/or leucocyte esterase are not specific indicators of UTI, and should not be used in place of laboratory examination. The dipstick method is most likely to be useful as a screening test to exclude UTI in children, but may be less suitable for infants. It should not be used to diagnose urinary tract infection.