Value of urinary gram staining in the diagnosis of urinary tract infection in catheterized patients

This study was designed to evaluate the urinary Gram stain as a screening test for the diagnosis of urinary tract infection in catheterized patients, using quantitative urine culture as gold standard. Gram staining and urine culture were carried out on urine samples from 107 catheterized patients. The sensitivity, specificity, positive predictive values and negative predictive values of the test were 73.5%, 77.7%, 76.4% and 75.0% respectively. It is concluded that due to high false negative [26.5%] and false positive [22.3%] rate, Gram staining is not reliable screening test for the diagnosis of urinary tract infections, especially in catheterized patients