Study objective

Validated prediction rules identify febrile neonates at low risk for invasive bacterial infection. The optimal approach for older febrile infants, however, remains uncertain.

Methods

We performed a retrospective cohort and nested case-control study of infants 2 to 6 months of age presenting with fever (≥38.0 °C) to 1 of 5 emergency departments. The study period was from 2011 to 2019. The primary outcome was invasive bacterial infection, defined by the growth of pathogenic bacteria from either blood or cerebrospinal fluid culture. Secondary outcomes included obtaining bacterial cultures (blood, cerebrospinal fluid, or urine), administering antibiotics, and hospitalization. For the nested case-control study, we age-matched infants with invasive bacterial infection to 3 infants without invasive bacterial infection, sampled from the overall cohort.

Results

There were 21,150 eligible patient encounters over 9-years, and 101 infants had a documented invasive bacterial infection (0.48%; 95% confidence interval [CI], 0.39% to 0.58%). Invasive bacterial infection prevalence ranged from 0.2% to 0.6% among the 5 sites. The frequency of bacterial cultures ranged from 14.5% to 53.5% for blood, 1.6% to 12.9% for cerebrospinal fluid, and 31.8% to 63.2% for urine. Antibiotic administration varied from 19.2% to 46.7% and hospitalization from 16.6% to 28.3%. From the case-control study, the estimated invasive bacterial infection prevalence for previously healthy, not pretreated, and well-appearing febrile infants was 0.32% (95% CI, 0.24% to 0.41%).

Conclusion

Although invasive bacterial infections were uncommon among febrile infants 2 to 6 months in the emergency department, the approach to diagnosis and management varied widely between sites. Therefore, evidence-based guidelines are needed to reduce low-value testing and treatment while avoiding missing infants with invasive bacterial infections

中文翻译：

---

2 至 6 个月发热婴儿侵袭性细菌感染的患病率和管理

学习目标

经验证的预测规则可识别出低危的发热新生儿发生侵袭性细菌感染。然而，对于大龄发热婴儿的最佳治疗方法仍不确定。

方法

我们对 2 至 6 个月大的婴儿进行了一项回顾性队列和巢式病例对照研究，这些婴儿因发烧 (≥38.0 °C) 到 5 个急诊科中的 1 个就诊。研究时间为 2011 年至 2019 年。主要结果是侵袭性细菌感染，定义为血液或脑脊液培养物中致病菌的生长。次要结果包括获得细菌培养物（血液、脑脊髓液或尿液）、使用抗生素和住院治疗。对于巢式病例对照研究，我们将患有侵袭性细菌感染的婴儿与 3 名未患侵袭性细菌感染的婴儿进行年龄匹配，从整个队列中抽取样本。

结果

9 年期间共有 21,150 名符合条件的患者就诊，101 名婴儿有侵袭性细菌感染记录（0.48%；95% 置信区间 [CI]，0.39% 至 0.58%）。5 个地点的侵袭性细菌感染患病率在 0.2% 到 0.6% 之间。血液细菌培养的频率为 14.5% 至 53.5%，脑脊液为 1.6% 至 12.9%，尿液为 31.8% 至 63.2%。抗生素给药率从 19.2% 到 46.7% 不等，住院率从 16.6% 到 28.3% 不等。根据病例对照研究，先前健康、未接受过预处理且外表良好的发热婴儿的侵袭性细菌感染患病率估计为 0.32%（95% CI，0.24% 至 0.41%）。

结论

尽管侵袭性细菌感染在急诊科 2 至 6 个月的发热婴儿中并不常见，但诊断和管理方法在不同地点之间差异很大。因此，需要基于证据的指南来减少低价值的检测和治疗，同时避免因侵袭性细菌感染而失踪的婴儿