Demonstration of bacteriuria in elderly hospitalized patients. Comparison between leukocyte and nitrite strips and culture

: The purpose of this study was to assess the accuracy of test strips for urinary nitrite and leucocytes for detection of bacteriuria in elderly patients. The material consisted of 213 urine samples from 85 women and 26 men (median age 79 years, range 60-93 years) within the first two days in hospital. The results of the test strip reactions were read in the department and in the laboratory. The strip test results and symptoms of UTI were compared with culture results. 27% of the samples showed significant bacteriuria on culture (> or = 10(5) colonies/ml urine). 21% of the 102 patients who had submitted two urine samples within the first two days had significant bacteriuria in both samples. Less than half of these patients had symptoms of UTI. The false negative rate of test strips (defined as the number of proven laboratory UTIs not demonstrated by the test strips, expressed as a percentage of the total number of proven UTIs) was 29% in the department and in the laboratory it was 13%. 15% of the test strips at the laboratory failed to detect significant E. coli infections which were predominant. In conclusion, we found that it is advisable to perform urine culture if symptoms of urinary tract infections are present.