Evaluation of universal antenatal screening for group B streptococcus

Area of Science:

• Neonatal infections
• Maternal health
• Infectious disease epidemiology

Background:

• Group B streptococcal (GBS) disease is a leading cause of infection in newborns within the first week of life.
• National guidelines in 2002 mandated universal antenatal screening for GBS colonization to guide intrapartum chemoprophylaxis.

Purpose of the Study:

• To evaluate the implementation and impact of universal GBS screening guidelines on intrapartum antibiotic use and early-onset GBS disease.
• To compare GBS screening practices and outcomes between 2003-2004 and a previous period (1998-1999).

Main Methods:

• Retrospective cohort study using data from the 10-state Active Bacterial Core surveillance system.
• Abstracted labor and delivery records for live births and all cases of early-onset GBS disease in infants <7 days old.
• Compared screening and antibiotic administration rates with a similar 1998-1999 study.

Main Results:

• GBS screening rates increased from 48.1% (1998-1999) to 85.0% (2003-2004), with intrapartum antibiotic exposure rising from 26.8% to 31.7%.
• Chemoprophylaxis was given to 87.0% of GBS-positive term-delivering women but only 63.4% of preterm women with unknown status.
• Overall early-onset GBS disease incidence was 0.32/1000 live births; preterm infants had higher incidence (0.73/1000) but most cases (74.4%) occurred in term infants. Missed screening contributed to 13.4% of GBS cases in term infants.

Conclusions:

• National guidelines for universal GBS screening were rapidly adopted by healthcare providers.
• Improvements in managing preterm deliveries and optimizing laboratory processes for GBS culture results are crucial for further reducing early-onset GBS disease.