Document Type: Original Research

Authors

1 Associate Professor of Pathology,Shahid Beheshti University of Medical Sciences,Tehran.

2 Medical Student, Shahid Beheshti University of Medical Sciences,Tehran.

3 Director of Microbiology Lab,Emam Hossein Hospital,Tehran

Abstract

Background and Objective: This study was undertaken to assess the ability of standard urinalysis (UA) and hemocytometer white blood cell (WBC) counts for the diagnosis of urinary tract infection (UTI) in patients with urinary symptoms. Materials and Methods: A total of 600 patients with symptoms of urinary tract infection were enrolled in this prospective study. Standard UA, hemocytometer WBC counts, and quantitative urine culture tests were performed on the specimens. The results of UA and hemocytometry were compared with urine culture findings to determine the accuracy of these two methods in the diagnosis of UTI. In this regard, sensitivity, specificity, positive and negative predictive values, accuracy, and likelihood ratios were determined for each of the screening tests. Results: There were 91 positive urine cultures with at least 105 bacteria per milliliter. Sixtyseven patients were female. The results of UA and hemocytometry were as follows: sensitivity 64.8% and 77%; specificity 89% and 90.3%; positive predictive value (PPV) 51.3% and 58.8%; negative predictive value (NPV) 93.4% and 95.6%; and accuracy 85.3% and 88.4% respectively. Conclusion: Although hemocytometer WBC counts have a higher sensitivity, specificity, and positive predictive value than standard UA, the differences are not statistically significant (p>0.05).
 

Keywords