The performance of GeneXpert® PCR assay in detecting group B streptococcus colonization at labor

Background: The aim of this study was to assess the performance of GeneXpertR group B streptococcus (GBS) PCR assays in a Danish setting, using rectovaginal GBS culture at labor as the gold standard. Methods: Three hundred and sixty-six (366) women with one or more of the following risk factors for GBS carriage.GBS during current pregnancy, prior infant with EOGBS, temperature >38.0 °C during labor, preterm labor <37 weeks of gestation, rupture of membranes ≥18 hours.were included in the study. Intrapartum rectovaginal swab samples were tested at the bedside by GeneXpertR GBS PCR assay, and cultured on agar plates (Granada) with and without prior use of growth-selective enrichment broth. Results: The GeneXpertR GBS PCR assay showed a sensitivity of 91.7%, a specificity of 97.2%, a PPV of 92.6 %, and a NPV of 96.8%. The turnaround time of the assay was 50 minutes. Conclusions: The GeneXpertR has a high performance, indicating that the assay can be used in a clinical setting.