TY - JOUR T1 - Assessment of two methods for rapid intrapartum detection of vaginal group B streptococcal colonisation. JF - Journal of Clinical Pathology JO - J Clin Pathol SP - 752 LP - 755 DO - 10.1136/jcp.47.8.752 VL - 47 IS - 8 AU - A J Simpson AU - J A Mawn AU - S R Heard Y1 - 1994/08/01 UR - http://jcp.bmj.com/content/47/8/752.abstract N2 - AIMS--To compare two methods for the rapid detection of intrapartum vaginal carriage of group B streptococci (Streptococcus agalactiae) with standard culture techniques and to establish their suitability for routine use. METHODS--Vaginal swabs from 266 patients in labour were incubated in glucose broth in an anaerobic atmosphere for four to six hours. The Wellcogen Strep B latex particle agglutination test kit was subsequently used for antigen detection. In the second part of the study swabs from 117 women were assessed for the presence of group B streptococci using the ICON STREP B immuno-concentration assay (Hybritech). Both methods were compared with standard semiquantitative culture on Columbia horse blood agar and Islam's medium. RESULTS--In the first study vaginal carriage of group B streptococci was shown in 38 of 266 (14.3%) patients by culture. Latex particle agglutination with the Wellcogen kit detected 30 of these positive results (sensitivity 78.9%, specificity 100%). In those patients with moderate to heavy colonisation (> 10(4) colony forming units per millilitre) antigen was detected in all (26/26) culture positive patients (sensitivity 100%, specificity 100%). In the second study 16 (13.7%) patients were culture positive. The ICON test detected 11 positive results (sensitivity 68.8%, specificity 100%) and for heavy colonisation (10(5) cfu/ml) detected nine of nine cases (sensitivity 100%, specificity 100%). The ICON test took 10 to 15 minutes to perform. CONCLUSION--These tests are potentially useful for the rapid detection of group B streptococci vaginal colonisation in labour, particularly heavy colonisation. Both tests are insufficiently sensitive to replace standard culture methods. ER -