Localization of urinary tract infection in elderly, institutionalized women with asymptomatic bacteriuria.

We determined the site of urinary tract infection in 51 elderly, institutionalized women (mean age, 80.5 years) with asymptomatic bacteriuria by using the Fairley bladder washout technique. Thirty-four (67%) infections were localized in the kidney and 17 (33%) in the bladder. Women with renal infection were older than those with bladder infection (81.9 vs. 77.6 years of age; P = .04). The antibody-coated bacteria test had a sensitivity of 58%, specificity of 71%, positive predictive value of 82%, and negative predictive value of 43% for upper-urinary-tract infection. A quantitative urinary leukocyte count of greater than or equal to 20 leukocytes/mm3 had a positive predictive value of 80% and a negative predictive value of 88% for upper-urinary-tract infection. This study suggests that the majority of elderly, institutionalized women with asymptomatic bacteriuria have upper-urinary-tract infection. Both the antibody-coated bacteria test and the quantitative urinary leukocyte count may be useful as noninvasive tests for localization of urinary tract infection in this population.