Importance The Centers for Disease Control and Prevention plans to introduce hospital-onset bacteremia (HOB) as a health care-associated infection measure. The epidemiology and clinical characteristics of HOB among infants admitted to the neonatal intensive care unit (NICU) are unknown. Objective To estimate the rate of HOB among infants admitted to the NICU, measure the association of HOB risk with birth weight group and postnatal age, and estimate HOB-attributable mortality. Design, Setting, and Participants This retrospective multicenter cohort study and emulated trial from 2016 to 2021 included a convenience sample of 322 NICUs in the United States. Participants were infants admitted to participating NICUs for 4 or more days. Exposures The primary exposures were birth weight and postnatal age. Additional exposures included small for gestational age and central line presence. Main Outcomes and Measures The primary study outcomes were HOB and HOB-attributable mortality. Results Of 451 443 included infants, 250 763 (55.6%) were male, 200 680 (44.4%) were female, and 62 091 (13.8%) were born 1500 g or less. Of 9015 HOB events that occurred among 8356 infants (2%) during 8 163 432 days at risk (unadjusted incidence rate, 1.1 per 1000 patient-days; 95% CI, 1.0-1.2), 4888 HOB events (54.2%) occurred in the absence of a central line. Within the first 2 weeks after birth, the HOB rate was 14.2 per 1000 patient-days (95% CI, 12.6-16.1) among infants born 750 g or less, to 0.4 events per 1000 patient-days among infants born more than 2500 g (95% CI, 0.4-0.5). Among infants born 750 g or less, the relative HOB risk decreased by 90% after day 42 compared with days 4 to 14 (incidence rate ratio [IRR], 0.10; 95% CI, 0.1-0.1). Conversely, among infants born more than 2500 g, the relative HOB risk increased by 50% after day 42 compared with days 4 to 14 (IRR, 1.5, 95% CI, 1.2-1.9). Compared with otherwise similar infants without HOB, infants with HOB had an absolute difference in attributable mortality of 5.5% (95% CI, 4.7-6.3). Conclusions and Relevance This study found that HOB events in the NICU are associated with increased mortality. Birth weight is an important risk factor for HOB; however, the relative rate of HOB decreases over postnatal age among low-birth-weight infants and increases among infants born more than 2500 g. Identifying strategies to prevent HOB and programs to decrease HOB risk are urgently needed to reduce infant mortality.

中文翻译：

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新生儿重症监护病房患者中院内发生的菌血症。


重要性 美国疾病控制与预防中心计划将院内菌血症 (HOB) 作为一项医疗保健相关感染措施。新生儿重症监护室 (NICU) 收治的婴儿 HOB 的流行病学和临床特征尚不清楚。目的 评估入住 NICU 的婴儿 HOB 发生率，测量 HOB 风险与出生体重组和出生后年龄的相关性，并估计 HOB 归因死亡率。设计、设置和参与者 这项回顾性多中心队列研究和 2016 年至 2021 年模拟试验包括美国 322 个 NICU 的便利样本。参与者是在参与 NICU 住院 4 天或以上的婴儿。暴露 主要暴露是出生体重和产后年龄。其他暴露包括小于胎龄和中心线存在。主要结果和措施 主要研究结果是 HOB 和 HOB 归因死亡率。结果 451 443例婴儿中，男性250 763例（55.6%），女性200 680例（44.4%），出生体重1 500 g以下62 091例（13.8%）。在 8 163 432 天的风险期间，8 356 名婴儿 (2%) 中发生了 9015 起 HOB 事件（未经调整的发病率，每 1000 患者日 1.1 起；95% CI，1.0-1.2），其中 4888 起 HOB 事件 (54.2%) 发生在没有中心线。在出生后的前 2 周内，出生体重 750 克或以下的婴儿的 HOB 率为每 1000 患者日 14.2 次（95% CI，12.6-16.1），出生体重超过 2500 克的婴儿的 HOB 率为每 1000 患者日 0.4 次（95% CI，0.4-0.5）。在出生体重 750 克或以下的婴儿中，第 42 天后相对 HOB 风险比第 4 至 14 天降低了 90%（发生率比 [IRR]，0.10；95% CI，0.1-0.1）。 相反，在出生体重超过 2500 克的婴儿中，与第 4 至 14 天相比，第 42 天后相对 HOB 风险增加了 50%（IRR，1.5，95% CI，1.2-1.9）。与没有 HOB 的其他类似婴儿相比，患有 HOB 的婴儿的归因死亡率绝对差异为 5.5%（95% CI，4.7-6.3）。结论和相关性 本研究发现 NICU 中的 HOB 事件与死亡率增加相关。出生体重是 HOB 的重要危险因素；然而，在低出生体重婴儿中，随着出生后年龄的增长，HOB 的相对发生率会降低，而在出生体重超过 2500 克的婴儿中，HOB 的相对发生率会增加。为了降低婴儿死亡率，迫切需要确定预防 HOB 的策略和降低 HOB 风险的计划。