Group B Streptococcal infection in the first 90 days of life in North Queensland

Abstract

Group B Streptococcus (GBS) infection is recognised as an important cause for neonatal sepsis. To describe the incidence and risk factors for invasive GBS under 90 days of age in North Queensland from January 2002 to December 2011. Patients were identified with positive blood and cerebrospinal fluid cultures to obtain incidence figures. The Townsville district cohort was further investigated for the presence of maternal and fetal risk factors in a retrospective case-controlled study. Early onset GBS continues to occur at 0.43/1000 live births, and late onset disease at 0.38/1000 live births. Early onset GBS and late onset GBS are shown to be two distinct diseases. Early onset disease is significantly different from the control group for these risk factors: previous late fetal loss, prolonged rupture of membranes, inadequate intrapartum antibiotics, abnormal cardiotocography, delivery by emergency caesarean section, lower one minute Apgar scores and need for resuscitation at delivery. Significant variables for late onset disease are earlier gestation and need for resuscitation at birth, first born babies, multiple pregnancy and birth by emergency caesarean section. The incidence of early or late onset GBS in Aboriginal or Torres Strait Islanders was not significantly different. Group B Streptococcus continues to occur in North Queensland at higher than expected rates, and a new approach to its prevention should be considered. Previous fetal loss may be a risk factor which is under recognised. Babies with late onset infection appear to be significantly more preterm.