Evaluating the Impact of the 2017 Dutch Neonatal Early-Onset Sepsis Guideline.

BACKGROUND: In 2017, a new Dutch neonatal early-onset sepsis (EOS) guideline was implemented. It is an adaptation from the United Kingdom National Institute for Health and Care Excellence guideline and focuses on maternal and neonatal risk factors. We aim to assess if this guideline performs better at reducing the rate of antibiotic treatment for EOS than the old Dutch categorical EOS guideline, which focused primarily on group B streptococcus (GBS) testing and prophylaxis. METHODS: We performed a single-center retrospective cohort study in the Netherlands. Data were collected from two 12-month epochs (2015 vs. 2019). Neonates were included when treated for suspected EOS or when observed for an elevated EOS risk. RESULTS: The empirical antibiotic rate was 4.6% in both years. Prolonged antibiotic treatment (>48 u) increased from 24% in 2015 to 39% in 2019 ( P = 0.021). Adherence to the guideline decreased from 98% in 2015 to 84% in 2019 ( P < 0.001). Strict adherence in 2019 would have led to more antibiotic treatment (5.1% instead of 4.6%). The EOS incidence rate was comparable, namely 0.6% in 2015 and 0.0% in 2019 ( P = 0.480). The change in the definition of risk factors in 2019 led to less antibiotic treatment in case of a maternal fever during birth, from 48% in 2015 to 26% in 2019 ( P < 0.001). CONCLUSIONS: The new Dutch categorical EOS guideline does not achieve its intended purpose of reducing empiric antibiotic therapy for suspected EOS. We advocate the need for a new screening strategy.

Enhanced memory B-cell immune responses after a second acellular pertussis booster vaccination in children 9 years of age.

Whooping cough has made its comeback and the incidence of pertussis in countries with widespread pertussis vaccination is most prominent in individuals above 9 years of age. To control the burden of infection, several countries already introduced acellular pertussis (aP) booster vaccination in adolescents and/or adults. However, antibody levels wane rapidly after vaccination even at older age. In this longitudinal study we investigated the effect of a second aP booster on the pertussis-specific memory B-cell immunity in children 9 years of age that have previously been vaccinated according to the national immunization program. Longitudinal blood samples were taken before, one month and one year after the booster. Purified B-cells were polyclonally stimulated and frequencies of memory B-cells were identified by ELISPOT-assays specific for various pertussis antigens. In addition, IgG levels and avidity indices were measured with fluorescent bead-based multiplex immunoassays. Starting with low pertussis-specific antibody and memory B-cell levels, a typical booster response was measured at one month after vaccination with increased antibody and memory B-cell responses. Although these responses declined slightly after one year, they substantially exceeded pre-booster levels and the avidity indices of the anti-pertussis antibodies remained high. Furthermore, high numbers of pertussis-specific memory B-cells at one-month post-booster correlate quite reliably with the corresponding high antibody response at one-year follow-up. In conclusion, booster vaccination in children 9 years of age induced an enhanced pertussis-specific memory immune response that sustained at least for one year. Therefore, this study supports the introduction of booster vaccination in older age groups.