Evaluation of Leukocyte esterase and Nitrite dipstick tests with routine urine microscopic analysis in detecting urinary tract infections

Abstract

: Urinary tract infection is a global health problem affecting all age groups. is the most common cause of UTI followed by , staphylococcus haemolyticus and enterococci etc. The gold standard for detecting an UTI is the presence of pathogen in urine along with clinical symptoms and pyuria. Nitrite (NIT) and leukocyte esterase (LE) tests are two important dip stick tests used for screening UTI. A total of 202 patients who presented with clinical symptoms of UTI from January 2023 to December 2023 were evaluated for urine routine and culture examination. LE and NIT dipstick tests were evaluated and change of colour was considered positive. Microscopic examination of urine was performed manually and urine culture with count of > 10 CFU/ml was considered positive. Statistical data was analysed using IBM SPSS v 29.0.2.0 (20) and Microsoft Excel. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated for both tests.: LE had a sensitivity of 47.22% whereas NIT was much less sensitive (15.27%). Specificity of NIT (99.23%) was higher in comparison to LE (81.53%). NIT had overall better PPV and NPV (91.66%, and 67.89%) as compared to LE (58.62% and 73.61%). The accuracy of LE and NIT were 69.3% and 69.8% respectively. A positive correlation was also seen with increasing WBC count and positive urine culture.: Urine culture along with clinical and routine analysis is necessary for definitive diagnosis of UTI but importance of dipstick chemical examination should not be underestimated. LE and NIT have an additional benefit of quick results in comparison to culture which takes at least 24 hours.