Epidemiology of Late and Very Late Onset Group B Streptococcal Disease: Fifteen-Year Experience From Two Australian Tertiary Pediatric Facilities.

BACKGROUND: Group B Streptococcus (GBS) is a recognized cause of sepsis and meningitis, particularly in infants. Early onset (<7 days) GBS disease has been well characterized, whereas the epidemiology of late onset disease (LOD, 7-89 days) and very late onset disease (VLOD, ≥90 days) is less well understood. The aims of this study were to assess risk factors, presentation, management and outcome for GBS LOD and VLOD.

METHODS: Microbiology laboratory databases and hospital diagnostic coding for Sydney Children's Hospital and the Children's Hospital at Westmead were investigated for patients ≥7 days of age diagnosed with GBS bloodstream infection or meningitis from January 1, 2000 to December 31, 2014 (15 years). Subjects' medical records were reviewed to confirm diagnosis and analyze risk factors, presentation, management and outcome.

RESULTS: Eighty-seven cases of LOD and 28 cases of VLOD were identified, including 49 cases of bloodstream infection and 66 cases of meningitis. No significant differences in risk factors or presentation were identified between LOD and VLOD. Patients with LOD were more likely to develop sequelae compared with VLOD [odds ratio (OR): 3, 95% confidence interval (CI): 1.03-8.77]. Female sex was the only significant risk factor identified for GBS meningitis (OR: 3.5, 95% CI: 1.5-8.1). GBS meningitis was significantly associated with neurodevelopmental impairment or death compared with bloodstream infection (OR: 30, 95% CI: 6.4-140.6).

CONCLUSIONS: GBS LOD and VLOD are encountered in similar at-risk populations, with LOD associated with higher morbidity. Infants presenting with meningitis are at significantly higher risk of sequelae compared with bloodstream infection.