Prospective study of peripartum group B streptococcus colonization in Japanese mothers and neonates

Area of Science:

• Obstetrics and Gynecology
• Neonatal Medicine
• Infectious Diseases

Background:

• Group B Streptococcus (GBS) causes significant neonatal, infant, and maternal infections globally.
• Current Japanese guidelines mandate culture-based GBS screening and intrapartum antibiotic prophylaxis (IAP), yet infection rates have plateaued.
• Limitations include missed screenings, intermittent colonization affecting accuracy, and IAP's ineffectiveness against late-onset GBS disease.

Purpose of the Study:

• To evaluate maternal and neonatal GBS colonization using polymerase chain reaction (PCR).
• To assess GBS capsular type distributions and explore late-onset disease transmission routes.
• To identify limitations of current GBS screening and prophylaxis strategies in Japan.

Main Methods:

• Maternal and neonatal GBS colonization was assessed in 525 mother-neonate pairs using PCR.
• Comparison of GBS detection rates between PCR and traditional culture methods.
• Analysis of GBS capsular types and discrepancies between maternal and neonatal colonization.

Main Results:

• PCR demonstrated higher GBS detection rates compared to culture methods.
• Significant discrepancies were observed between antepartum and intrapartum GBS colonization.
• GBS was detected in 3.5% of neonates born to mothers initially testing negative for GBS.

Conclusions:

• Current GBS screening and IAP methods have notable limitations in preventing both early- and late-onset GBS disease.
• PCR offers improved detection of GBS colonization compared to standard culture.
• Maternal GBS vaccination presents a promising future strategy for enhanced prevention.