An Evaluation of Two Rapid Bacteriuria Screening Procedures

Two commercially available rapid bacteriuria screening procedures were evaluated for routine screening for 10 or more colony forming units per milliliter of pathogenic bacteria in two female patient populations. In 694 obstetric patients with 56 cases of significant bacteriuria, the sensitivity, specificity, positive predictive, and negative predictive values, respectively, were as followsfor Chemstrip LN, 69.6, 83.4, 26.9, and 96.9%; and for Bac-T-Screen, 96.4, 56.0, 16.1, and 99.4%. In 143 nonpregnant females with 32 cases of significant bacteriuria, these values werefor Chemstrip LN, 71.9, 75.7, 46.0, and 90.3%; and for Bac-T-Screen, 84.4, 65.8, 41.5, and 93.6%. These results indicate that the LN strip did not have acceptable sensitivity in either patient group. The Bac-T-Screen had better sensitivity, particularly for obstetric patients; however, a high false-positive rate and high cost per test may restrict its use in those clinical settings where culture is available and cost-effective.