Clinical characteristics, outcomes and molecular epidemiology of group B streptococcal disease in young infants in the Netherlands.

OBJECTIVES

Group B streptococcus (GBS) disease remains a major cause of morbidity and mortality in young infants. We conducted a prospective multi-centre cohort study to evaluate clinical outcomes, molecular epidemiology, and coverage of potential maternal vaccines candidates in the Netherlands.

METHODS

Between January 1st, 2018, and December 31st, 2024, infants aged 0-89 days with culture-confirmed GBS sepsis or meningitis were identified through the Netherlands Reference Laboratory of Bacterial Meningitis. Clinical data, including GBS serotype, were collected for all cases.

RESULTS

We included 375 infants; 212 (57%) had early-onset disease (0-6 days) and 163 (43%) late-onset disease (7-89 days). Overall, 205 (55%) infants had sepsis, 78 (21%) definitive meningitis, and 92 (24%) probable meningitis. Complications occurred in 220 (59%) infants; 331 (88%) recovered without abnormalities at discharge. Mortality was 5%. Among mothers eligible for intrapartum antibiotic prophylaxis, 40% received prophylaxis. Serotype III was most common (57%), followed by Ia (17%) and V (8%). Serotype III was associated with meningitis and late-onset disease. Potential coverage was 96% for the GBS6 vaccine and 99% for GBS-AlpN.

CONCLUSIONS

GBS disease in young infants remains associated with high morbidity and mortality. Limited adherence to intrapartum antibiotic prophylaxis highlights prevention gaps and supports maternal GBS vaccination.