Screening for bacteriuria with the LN strip test.

Recently, the LN strip test was introduced for purposes of rapid screening of urine specimens for bacteriuria. The LN strip test permits detection of urinary leukocyte esterase and nitrite. A total of 2,481 unselected urine specimens from three tertiary care hospitals were examined using the LN strip test and the results were compared with those obtained with a conventional quantitative culture technique. When the results of the leukocyte esterase and nitrite tests were combined, the sensitivity and specificity of the LN strip test were 88.8% and 71.3%, respectively, based on culture results of greater than or equal to 10(5) CFU/ml. Test sensitivity decreased at greater than or equal to 10(4) CFU/ml, whereas test specificity increased.