The value of urinalysis in presumptive diagnosis of urinary tract infection in children

Abstract

Background Definite diagnosis of urinary tract infection (UTI) should only be established based on culture of urine specimen, otherwise it would be considered presumptive. Since urinalysis provides more rapid information than urine culture, clinicians should consider to utilize urinalysis as a decision-making tool for initiating treatment of UTI. Objective To determine the sensitivity, specificity, predictive values, and accuracy of several urinalysis parameters, namely the nitrite, leukocyte esterase (LE), Gram staining, and methylene blue reductase (MBR) tests, in supporting the diagnosis of UTI. Methods This diagnostic test was done on 30 subjects with pyuria during the period of April to June 2004. The sensitivity, specificity, positive predictive value (PPV), negative predicitve value (NPV) aswell as the accuracywere calculated for each urinalysis parameter with urine culture as the gold standard. The relationship between categorical variables was analyzed by Fishers exact test or chi square test. Results The sensitivity, specificity, PPV, NPV and accuracy for nitrite test, leukocyte esterase (LE) test, Gram staining, and MBR test were respectively as follows: nitrite test showed 90.5%, 66.7%, 86.4%, 75%, and 83.3%; LE test yielded 95.2%, 33.3%, 76.9%, 75%, and 76.4%; Gram staining100%, 44.4%, 80.8%, 100%, and 83.3%; and MBR test 85.7%, 100%, 100%, 75%, and 90%. ConclusionsTheMBR, among other urinalysis routine tests, has the highest specificity and accuracy as well as high sensitivity in establishing a presumptive diagnosis of UTI [Paediatr Indones 2008;48:199-203].