Does delocalised PCR for Streptococcus B in the labour ward allow adequate administration of antibiotics to prevent early neonatal infection?

Introduction

Streptococcus B is a commensal infectious agent of the intestinal and genitourinary tract. It is often implicated in early neonatal infections. Some 10 %–30 % of women are colonised by this bacterium. Screening for carriage in women before delivery prior to antibiotic prophylaxis is thus essential. In recent years, real-time PCR tests have been developed. Our main objective was to determine whether screening for Streptococcus B carriage by PCR on admission (gold standard GeneXpert) permits complete antibiotic prophylaxis.

Materials and methods

This was an observational, retrospective study. Data set from all patients with a delocalised PCR for Streptococcus B (GeneXpert Instrument System) on arrival at the maternity hospital were collected between January 2022 and February 2023. We recorded 3467 test results, of which 344 were positive for Streptococcus B carriage. A total of 236 positive patients were included in the analysis. Antibioprophylaxis was considered complete when the patient had received at least one dose more than 4-hours before birth.

Results

Of the 236 patients, antibiotic therapy was incomplete in 53 cases (22.4 %) because vaginal delivery or caesarean section occurred less than 4-hours after the first dose. Antibioprophylaxis was not initiated in 33 cases. The main reason was for rapid labour in 28 cases (11.9 %). The 5 remaining cases did not receive antibiotics because probable omission by the team (2.1 %).

Conclusion

Delocalised PCR allows complete antibiotic prophylaxis against Streptococcus B in 63.6 % of cases, offering scope for improvement. While it will not be possible to improve antibioprophylaxis in case of rapid labour (within 3 hours after arrival), we should be able to prevent omissions (2.1 %) and, above all, reduce the birth rate before the second dose (22.4 %) by administering the first dose more quickly.