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

Abstract

The performance of GeneXpert® PCR assay in detecting group B streptococcus colonization at labor Mohammed Rohi Khalil1, *, Jens Kjølseth Møller2 , Stine Yde Nielsen2 1Department of Gynecology and Obstetrics, Kolding Hospital, University Hospital of Southern Denmark, 6000 Kolding, Denmark 2Department of Clinical Microbiology, Vejle Hospital, University Hospital of Southern Denmark, 7100 Vejle, Denmark *Correspondence: mohammed.khalil@rsyd.dk (Mohammed Rohi Khalil) DOI:10.31083/j.ceog.2021.03.2485 This is an open access article under the CC BY 4.0 license (https://creativecommons.org/licenses/by/4.0/). Submitted: 21 January 2021 Revised: 12 February 2021 Accepted: 12 March 2021 Published: 15 June 2021 Background: The aim of this study was to assess the performance of GeneXpert® 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 GeneXpert®GBS PCR assay, and cultured on agar plates (Granada) with and without prior use of growth-selective enrichment broth. Results: The GeneXpert® 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 GeneXpert®has a high performance, indicating that the assay can be used in a clinical setting. Keywords Group B streptococcus; Early-onset neonatal infection; Polymerase chain reaction; Rapid intrapartum assay; GeneXpert®