Early-onset group B streptococcal disease in Queensland: A population study

Abstract

Background: Intrapartum chemoprophylaxis reduces the incidence of early-onset group B streptococcal disease (EOGBSD) in newborns, a disease with estimated global incidence of 0.53 per 1000 live births. Some guidelines advise that intrapartum antibiotics should be offered following universal antenatal screening for GBS carriage, and others, based on clinical risk factors alone. Since 1999, Queensland guidelines (revised and published online in 2010) have recommended a modified risk-factor approach. This study explores the trend of EOGBSD in Queensland in the setting of these guidelines. Methods: A state-wide retrospective population-based beforeand- after study was performed. Live infants born from January 2000 to December 2014 in whom GBS was cultured from blood or CSF within 7-days of age were identified through pathology database extraction, allowing near-complete, population-based case identification. Records of infants with EOGBSD born in 2011-2014 were reviewed. Case characteristics and outcomes were compared with previous unpublished 2000-2004 audit of EOGBSD in Queensland. Results: Mean incidence of EOGBSD in Queensland from 2000-2014 was 0.33 per 1000 live births (SD±0.08) with no change in trend over time. The case-mortality rate in 2011-2014 was 1.2% compared to 11.9% in 2000-2004 (RR [95% CI]): 0.1 [0.01 to 0.77] p=0.03). The proportion of preterm infants with GBS decreased from 29.8% to 13.3% (0.44 [0.23 to 0.84] p=0.01). Only 42%of cases with risk factors received intrapartum antibiotics. Conclusions: EOGBSD incidence rate in Queensland remained low from 2000-2014. From 2011-2014, case-mortality rate has improved and the proportion of preterm cases decreased. Missed opportunities for intrapartum antibiotics remain.L6215327172018-04-09 <br />