2020 Volume 23 Issue 2 Pages 79-85
Febrile urinary tract infections require prompt diagnosis and treatment due to their rapidly progressive nature. Although Gram staining of the urine specimens is generally preferred for the initial assessment of causative organisms, this procedure is not often carried out in routine clinical practice because of restrictions in time, manpower, and materials. Our study focused on microscopic examination of unstained urinary sediments as an alternative and simple method to identify the morphology of bacteria in the urine compared with Gram staining. We evaluated 103 cases in which urine culture was carried out, and calculated the sensitivity and specificity of morphological assessment of bacteria in the urine by the urinary sediment microscopy test in comparison with the species of isolated bacteria (≥ 1 × 105 CFU/mL) from urine culture as the standard. The sensitivity and specificity of the test were 54.5% (95% confidential interval [CI], 23.4–83.3%) and 95.7% (95% CI, 89.2–98.8%), respectively, for cocci, and 93.8% (95% CI, 79.2–99.2%) and 88.7% (95% CI, 79.0–95.0%), respectively, for bacilli. In 3 of 4 discordant cases between the urinary sediment microscopy test and the result of urine culture, cocci were misinterpreted as bacilli. This study was the first to evaluate the performance of the urinary sediment microscopy test. Our study suggests that this test is convenient and useful in the outpatient setting where time and manpower are limited.
