Comparison of Xpert GBS v. culture for rapid detection of group B streptococcus in pregnant women : sensitivity, specificity and predictive values
Loading...
Date
Authors
Said, Mohamed
Dangor, Yusuf
Mbelle, Nontombi Marylucy
Sihlabela, A.
Lekalakala, M.R.
Ismail, Farzana
Journal Title
Journal ISSN
Volume Title
Publisher
Health and Medical Publishing Group
Abstract
BACKGROUND. Group B streptococcus (GBS) is a leading cause of invasive disease, particularly in newborns. Seventy-five percent of neonates
will be colonised by mothers carrying the organism. Confirmation of maternal colonisation with GBS is essential for prompt treatment and
prevention of neonatal sepsis. The current gold standard of culture for isolation of GBS has a disadvantage of long turnaround time (24 -
72 hours). Rapid assays are required to determine maternal carriage of GBS.
OBJECTIVES. To determine the usefulness of the Xpert GBS technology v. culture methods to detect GBS carriage in pregnant women.
METHODS. This was a prospective observational study of 284 pregnant women between 26 and 37 weeks’ gestation. Two vaginorectal
swabs were collected from each participant. One swab was processed using the gold-standard culture method, while the second swab was
processed using the Xpert GBS assay. The performance of the Xpert GBS assay was then compared with that of the culture method.
RESULTS. Two swabs were processed from each of 284 pregnant women between 26 and 37 weeks’ gestation. Culture detected 70 GBS isolates
from a total of 279 specimens (25.1%), whereas the Xpert GBS detected 66 positive specimens (23.7%). The Xpert GBS assay had a sensitivity
of 87% and specificity of 98%, with a positive predictive value of 92% and a negative predictive value of 96%.
CONCLUSIONS. The Xpert GBS assay is a rapid and sensitive tool for prenatal detection of GBS. The assay should ideally be available in every
labour ward, where women can be screened for GBS on arrival.
Description
The research described in this article was an MMed project
of MS, the main author.
Keywords
Invasive disease, Newborns, Mothers, Group B streptococcus (GBS)
Sustainable Development Goals
Citation
Said, M., Dangor, Y., Mbelle, N. et al. 2018, 'Comparison of Xpert GBS v. culture for rapid detection of group B streptococcus in pregnant women: Sensitivity, specificity and predictive values', South African Medical Journal, vol. 108, no. 12, pp. 1032-1035.