Role of dipsticks in diagnosis of urinary tract infection in children: is it accurate enough

Abstract

BACKGROUND:Urinary tract infection (UTI) is a common problem in childhood. Urine culture is the Gold standard for diagnosis. Dipstick tests for leucocyte esterase reaction (LE) and nitrites (N) are bedside tests useful in the diagnosis of UTI. Accuracy of above tests have been extensively investigated in other countries. No published data is available from Sri Lankan children up to date.OBJECTIVES:To study the diagnostic accuracy of dipstick tests in diagnosis of UTI in Sri Lankan children.DESIGN, SETTING AND METHOD:Descriptive, cross sectional study was conducted in a medical ward at Lady Ridgeway Hospital for Children. 300 children less than 12 years, clinically suspected of UTI were recruited. Dipstick tests (LE and N) and urine culture were performed.RESULTS:Of the 300 children, 118 (39.3%) had positive cultures (pure growth of bacteria >105 cfu/ml), 16 (54%) had negative cultures and 20 (6.7%) had mixed growth. Cultures with mixed growths were excluded and remaining 280 were analyzed. Mean age of the participants was 49 months (SD 41.3), 148 (53%) being males.Accuracy of dipsticks tests (LE and N) in detecting UTI was as follows. LE and N in combination had a sensitivity of 97.5%, specificity of 77.2%, positive predictive value (PPV) of 75.6% and negative predictive value (NPV) of 97.6%. LE alone showed a sensitivity of 96.6% specificity of 77.7%, PPV of 76% and NPV of 96.9%. Corresponding values for N alone were 78.8%, of 97.5%, 95.8% and 86.3% respectively.CONCLUSIONS:Leucocyte esterase reaction and nitrite test in combination showed promising results to detect UTI in children. LE was more sensitive and N was more specific.