Streptococcus agalactiae in pregnancy and the impact of recommendations on adherence to guidelines: an Italian area-based study

Abstract

Introduction

Streptococcus agalactiae, a species of β-haemolytic streptococcus belonging to Lancefield’s group B (GBS), is known as a common infecting agent transmitted to infants during childbirth, causing sepsis, meningitis, or both, with a high incidence of mortality. Following the observation of a great variability between regional laboratories both in the methodology and in the results of tests for the detection of GBS in pregnancy, with high percentages of false negative results, in 2010 the Department for Health Policies of Piedmont, Italian region, issued specific recommendations for adhere to international guidelines. Our aim was to assess whether the impact of the publication of the recommendations has been lasting over time.

Methods

We analyzed the regional birth certificate register from 2006 to 2018, to evaluate the annual number of deliveries, the number of Streptococcus agalactiae tests in pregnancy and the percentage of positive culture results. We also evaluated the consistency of the percentage of positive tests with the expectations based on the guidelines and compared the two time periods before and after introduction of regional recommendations using a multivariate regression model.

Results

The mean proportion of women tested for GBS vaginal-rectal swabs during pregnancy increased from 83.5% in 2006 to 90.7% in 2018 with the biggest rise in 2010, the t-test for the comparison of the two means was statistically significant (p < .001). The mean positivity rate increased from 12.7% to 19.2%, with a rise in 2010, with a significant t-test (p < .001).

Conclusion

The results suggested a significant impact of the recommendations on the compliance and results regarding the carrying out and culture of vagino-rectal swabs for GBS, with better appropriateness of peripartum antibiotic therapy and possible reduction of GBS related neonatal sepsis.

Keywords:

• Pregnancy
• Streptococcus agalactiae
• screening
• guidelines
• GBS
• vagino-rectal swab

Acknowledgment

We thank Alberto Berardi, Associate Professor in Pediatrics and Head of the Neonatal Intensive Care Unit Azienda Ospedaliero-Universitaria Policlinico, Modena, Italy and Roberta Creti, Ph.D, Department. of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy for critical review of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).