Background, presentation and outcomes GBS is a naturally occurring bacterium, carried in the vagina and lower intestine of approximately 20-25% of women in the UK (Daniels et al, 2011), without causing symptoms or harm to the carrier. Two-thirds of infected babies present with early-onset GBS (EOGBS) at 0-6 days and the rest present with late-onset GBS (LOGBS) at 7-90 days (Heath, 2016). EOGBS is more likely to present as sepsis and pneumonia, typically in the first day of life, caused by materno-fetal transmission around birth. The risk of EOGBS is considerably reduced by intrapartum antimicrobial prophylaxis (IAP) in labour (Lin et al, 2001). Worldwide, an estimated 205 000 babies developed EOGBS in 2015 (Seale et al, 2017). LOGBS is more likely to present as meningitis and sepsis, and the source of the bacteria causing disease may be the mother, the environment or other sources. LOGBS is not preventable by IAP (Jordan et al, 2008). LOGBS is uncommon after 4 weeks of age and almost unknown after 12 weeks. Worldwide, an estimated 114 000 babies developed LOGBS in 2015 (Jordan et al, 2008) Other GBS infections are a recognised cause of invasive disease in peripartum women, fetal infections, stillbirth and preterm labour. While most babies recover from their GBS infection, in 2015, an estimated 90 000 died and 10 000 survived with disability worldwide (Seale et al, 2017).