Early antibiotic exposure in very-low birth weight infants and infection risk at 3-7 days after birth.

OBJECTIVE: To determine rates of late-onset infection (LOI) during postnatal days 3-7 among preterm infants, based on antibiotic exposure during days 0-2. STUDY DESIGN: Retrospective cohort study of infants born <1500 grams and ≤30 weeks gestation, 2005-2018. We analyzed the incidence and microbiology of LOI at days 3-7 based on antibiotic exposure during postnatal days 0-2. RESULTS: The cohort included 88,574 infants, of whom 85% were antibiotic-exposed. Fewer antibiotic-exposed compared to unexposed infants developed LOI (1.5% vs. 2.1%; adjusted hazard ratio, 0.28, 95% CI 0.24-0.33). Among antibiotic-exposed compared to unexposed infants, Gram-negative (38% vs. 28%, p = 0.002) and fungal (11% vs. 1%, p < 0.001) species were more commonly isolated, and gram-positive organisms (49% vs. 70%, p < 0.001) were less commonly isolated. CONCLUSIONS: We observed low overall rates of LOI at days 3-7 after birth, but antibiotic exposure from birth was associated with lower rates, and with differing microbiology, compared to no exposure.

Duke Scholars

Author Daniel Kelly Benjamin Jr. Pediatrics, Infectious Diseases

Author Rachel Gottron Greenberg Pediatrics, Neonatology