Efficacy of nitrite, leucocyte esterase dipsticks and urine microscopy in the diagnosis of urinary tract infection in febrile children aged between 1 year to 5 years –a cross sectional diagnostic study

Introduction: Recognition of urinary tract infection (UTI) in children may be difficult because of the non-specific presenting symptoms, particularly in younger children. Urine culture is still considered the gold standard in diagnosis of UTI, but culture takes 48 hours for the result, and culture facility may not be available in rural setup of our country. So dip sticks have the advantage of being quick and easy to perform, interpret and cost effective. Leucocyte esterase (LE) and Nitrite (NIT) Dip stick test have been commonly used in diagnosing UTI. Presence of one dip stick with high specificity may be a reliable and early method to diagnose UTI. So, this study was conducted to know the effectiveness the dipsticks over urine culture. Objective: To evaluate the effectiveness of Nitrite, Leucocyte esterase dipsticks and urine microscopy in diagnosis of UTI in febrile children between 1 to 5 years of age. Material and Methods: A cross sectional diagnostic study was done on 450 febrile children between age group of 1 to 5 years. Children who were on antibiotics 48 hours prior were excluded from the study. After obtaining valid informed consent from the parents, mid stream urine sample was collected in two sterile urine containers under aseptic precautions. One sample was processed for LE, NIT dipstick and urine microscopy and the other one for urine culture. The test could be read either visually by human eye or instrumentally using the SD Urometer urine chemistry analyzer. The test handling method and precautions as given in the Urocolor test manual were carefully followed. Results: Out of 450 urine samples, LE dip stick was positive in 186(41.3%) & there was statistically significant difference in positivity of LE dipstick in culture positive and negative samples. Out of 450 samples, urine culture was positive in 50 (11.1%). Out of 50 culture positive urine samples, NIT dipstick was positive in 32 cases. In 400 culture negative cases, NIT dipstick was positive in 43 (10.7%). E. coli was the predominant organism isolated in 35(70 %) out of 50 cases followed by klebsiella (10%). PPV, NPV, Sensitivity, Specificity of LE in predicting UTI was calculated. The combined sensitivity, specificity when Pus cells, LE, NIT dipstick were combined was 50%, 90% respectively. Conclusion: The present study suggests that a combination of leukocyte esterase and nitrite dipsticks is a reliable parameter in predicting UTI in febrile children. This study also suggests that, because of high specificity and NPV, LE and NIT urinary dipsticks could be used in daily OPD basis practice, along with urinary microscopy, to diagnose UTI.