Neonatal infection with group B streptococcus (GBS) is an important cause of infant mortality. Intrapartum antibiotics reduce early‐onset GBS sepsis, but recommendations vary as to whether they should be offered following antenatal screening or based on risk factors alone. We aimed to determine the incidence of early‐onset GBS sepsis in New Zealand five years after the publication of national risk‐based GBS prevention guidelines.

Materials and Methods
Prospective surveillance of early‐onset GBS sepsis (defined as infection in the first 48 h of life) was undertaken between April 2009 and March 2011 through the auspices of the New Zealand Paediatric Surveillance Unit as part of a survey of infection presenting in the first week of life.

There were 29 cases of confirmed early‐onset GBS sepsis, including one case of meningitis, giving an incidence rate of 0.23 per 1000 (95% CI 0.16–0.33) live births. Three infants (10.3%) died. In 16 cases (55%), a maternal risk factor qualifying the mother for intrapartum antibiotics was present, but only five (31%) received this intervention. A retrospective review of the major hospital laboratory databases for this period identified two additional cases. A secondary sensitivity analysis taking account of these cases provided an estimated national incidence of 0.26 (95% CI 0.18–0.37) per 1000 live births.

Ten years after a similar survey and five years after promoting a single, risk‐based prevention protocol nationally, the incidence of early‐onset GBS disease in New Zealand has more than halved, but opportunities remain to further reduce the rate.