Neonatal Group B Streptococcal Infection in Australia: A Case-control Study

Area of Science:

• Neonatal infections
• Maternal health
• Epidemiology

Background:

• Group B Streptococcus (GBS) is a major cause of neonatal morbidity and mortality.
• Understanding risk factors and incidence is crucial for effective prevention.

Purpose of the Study:

• To determine maternal and neonatal risk factors for early-onset (EOGBS) and late-onset (LOGBS) group B Streptococcus infections.
• To establish the incidence of EOGBS and LOGBS in South Australia (SA) and the Northern Territory (NT).

Main Methods:

• A case-control study with a 2:1 matched control to case ratio.
• Retrospective data collection over a 16-year period (2000-2015) from tertiary hospitals in SA and NT.
• Inclusion of 139 confirmed GBS cases out of 188 suspected cases.

Main Results:

• EOGBS accounted for 56.1% of confirmed cases, while LOGBS comprised 43.9%.
• Incidence rates varied between SA and NT, with EOGBS confirmed incidence at 0.19/1000 (SA) and 0.36/1000 (NT) live births.
• Key risk factors for EOGBS included maternal GBS carriage, prior fetal death, Indigenous status, and maternal fever/chorioamnionitis. Sepsis, pneumonia, and meningitis were common presentations, with developmental delay noted at one year.

Conclusions:

• Group B Streptococcus remains a significant threat to newborns.
• Incorporating previous fetal death into GBS screening guidelines could enhance prevention efforts.
• Maternal GBS vaccination programs should be informed by region-specific epidemiological data.