Assessment of rapid identification tests for genital carriage of group B streptococci.

OBJECTIVE: The purpose of this study was to assess the relative value of reported methods for rapid identification of group B streptococcal colonization of the female genital tract. DATA SOURCES: Trials of group B streptococcal identification techniques published in peer-reviewed journals were located using a computerized literature search and cited references from relevant articles or text chapters. METHODS OF STUDY SELECTION: Reports were included in the analysis if the methodology fulfilled the following criteria: 1) A reference culture method was used for comparison; 2) performance characteristics were presented or could be calculated; 3) the method could be performed in a standard laboratory on a 24-hour-a-day basis; and 4) results could be routinely available within 12 hours. DATA EXTRACTION AND SYNTHESIS: Performance characteristics such as sensitivity, specificity, and predictive values for the various methods were evaluated and compared. Factors such as colonization rates and methods for identifying carriers were included in the overall assessment of test performance.
CONCLUSIONS: The overall sensitivity of current methods for the rapid detection of group B streptococcal colonization is low. However, some rapid antigen detection tests are highly sensitive in identifying heavily colonized patients, and therefore may be useful for selecting high-risk patients for intrapartum antibiotic prophylaxis.