Rapid intrapartum test for maternal group B streptococcal colonisation and its effect on antibiotic use in labouring women with risk factors for early-onset neonatal infection (GBS2): cluster randomised trial with nested test accuracy study
Metadata
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BMC
Materia
Group B Streptococcus Colonisation Randomised controlled trial Accuracy Labour Pregnancy Antibiotics
Date
2022-01-14Referencia bibliográfica
Daniels, J.P... [et al.]. Rapid intrapartum test for maternal group B streptococcal colonisation and its effect on antibiotic use in labouring women with risk factors for early-onset neonatal infection (GBS2): cluster randomised trial with nested test accuracy study. BMC Med 20, 9 (2022). [https://doi.org/10.1186/s12916-021-02202-2]
Sponsorship
National Institute for Health Research (NIHR) 13/82/04; NIHR Birmingham Biomedical Research Centre at the University Hospitals Birmingham NHS Foundation Trust University of Birmingham; Beatriz Galindo (senor modality) ProgramAbstract
Background: Mother-to-baby transmission of group B Streptococcus (GBS) is the main cause of early-onset
infection. We evaluated whether, in women with clinical risk factors for early neonatal infection, the use of point-ofcare
rapid intrapartum test to detect maternal GBS colonisation reduces maternal antibiotic exposure compared
with usual care, where antibiotics are administered due to those risk factors. We assessed the accuracy of the rapid
test in diagnosing maternal GBS colonisation, against the reference standard of selective enrichment culture.
Methods: We undertook a parallel-group cluster randomised trial, with nested test accuracy study and
microbiological sub-study. UK maternity units were randomised to a strategy of rapid test (GeneXpert GBS system,
Cepheid) or usual care. Within units assigned to rapid testing, vaginal-rectal swabs were taken from women with
risk factors for vertical GBS transmission in established term labour. The trial primary outcome was the proportion of
women receiving intrapartum antibiotics to prevent neonatal early-onset GBS infection. The accuracy of the rapid
test was compared against the standard of selective enrichment culture in diagnosing maternal GBS colonisation.
Antibiotic resistance profiles were determined in paired maternal and infant samples. Results: Twenty-two maternity units were randomised and 20 were recruited. A total of 722 mothers (749 babies)
participated in rapid test units; 906 mothers (951 babies) were in usual care units. There was no evidence of a
difference in the rates of intrapartum antibiotic prophylaxis (relative risk 1.16, 95% CI 0.83 to 1.64) between the
rapid test (41%, 297/716) and usual care (36%, 328/906) units. No serious adverse events were reported. The
sensitivity and specificity measures of the rapid test were 86% (95% CI 81 to 91%) and 89% (95% CI 85 to 92%),
respectively. Babies born to mothers who carried antibiotic-resistant Escherichia coli were more likely to be
colonised with antibiotic-resistant strains than those born to mothers with antibiotic-susceptible E. coli.
Conclusion: The use of intrapartum rapid test to diagnose maternal GBS colonisation did not reduce the rates of
antibiotics administered for preventing neonatal early-onset GBS infection than usual care, although with
considerable uncertainty. The accuracy of the rapid test is within acceptable limits.