Factors Associated with Adverse Outcomes among Febrile Young Infants with Invasive Bacterial Infections

Objective: To determine factors associated with adverse outcomes among febrile young infants with invasive bacterial infections (IBIs) (ie, bacteremia and/or bacterial meningitis). Study design: Multicenter, retrospective cohort study (July 2011-June 2016) of febrile infants ≤60 days of age with pathogenic bacterial growth in blood and/or cerebrospinal fluid. Subjects were identified by query of local microbiology laboratory and/or electronic medical record systems, and clinical data were extracted by medical record review. Mixed-effect logistic regression was employed to determine clinical factors associated with 30-day adverse outcomes, which were defined as death, neurologic sequelae, mechanical ventilation, or vasoactive medication receipt. Results: Three hundred fifty infants met inclusion criteria; 279 (79.7%) with bacteremia without meningitis and 71 (20.3%) with bacterial meningitis. Forty-two (12.0%) infants had a 30-day adverse outcome: 29 of 71 (40.8%) with bacterial meningitis vs 13 of 279 (4.7%) with bacteremia without meningitis (36.2% difference, 95% CI 25.1%-48.0%; P <.001). On adjusted analysis, bacterial meningitis (aOR 16.3, 95% CI 6.5-41.0; P <.001), prematurity (aOR 7.1, 95% CI 2.6-19.7; P <.001), and ill appearance (aOR 3.8, 95% CI 1.6-9.1; P =.002) were associated with adverse outcomes. Among infants who were born at term, not ill appearing, and had bacteremia without meningitis, only 2 of 184 (1.1%) had adverse outcomes, and there were no deaths. Conclusions: Among febrile infants ≤60 days old with IBI, prematurity, ill appearance, and bacterial meningitis (vs bacteremia without meningitis) were associated with adverse outcomes. These factors can inform clinical decision-making for febrile young infants with IBI.