Urine Culture vs. Urine Dipstick vs. Urine Microscopy in UTI

A urinary tract infection (UTI) is an infection in any part of your urinary system — your kidneys, ureters, bladder and urethra. Most infections involve the lower urinary tract — the bladder and the urethra.Dipstick and microscopic urinalysis results were compared with urine culture results, which were used as the reference standard to determine presence or absence of urinary tract infection. Use of dipsticks and microscopic urinalysis instead of urine culture may decrease patient time and the cost of testing. Urine culture has the disadvantage of taking at least 48 hours to give a result. More rapid methods of urinary tract infection diagnosis are therefore desirable. The most widely used rapid tests are dipsticks. Dipstick tests have the advantage of being quick and easy to perform and can be carried out in primary care giving an immediate result. Microscopic examination of urine samples for leukocytes, erythrocytes or bacteria is considerably more time consuming and labor intensive than the dipstick method. But false positive and false-negative rates are significantly higher as compared with the microscopic examination. Studies suggests when only leukocyte esterase takes into consideration, sensitivity and specificity was 65% and 64%, respectively, whereas sensitivity and specificity in microscopic examination, when only leukocyte esterase takes into consideration, was 87% and 71%, respectively. Rapid diagnosis or exclusion of urinary tract infection is valuable both to the general practitioner and to the hospital physician. Therefore, dipstick test and microscopy analysis may be performed when a very rapid conclusion was desired. The study has suggested that both urinalysis methods can be used for rapid diagnosis. Urine culture is an expensive test for routine use and should not be applied unless the result of the nitrite, leukocyte or bloods are positive in dipstick or leukocyte, erythrocyte or bacteria are positive in microscopic examination.

The Cobio Automated Urine sediment system provides a fast, accurate and cost-effective method in urine microscopy analysis.

Reference:

Ramazan Memişoğulları, Hatice Yüksel, Hayriye Ak Yıldırım, Özlem Yavuz. Performance Characteristics of Dipstick and Microscopic Urinalysis for Diagnosis of Urinary Tract Infection. Eur J Gen Med 2010;7(2):174-178