Microbiological factors associated with neonatal necrotizing enterocolitis: protective effect of early antibiotic treatment

Aim: The incidence of necrotizing enterocolitis (NEC) strongly increased in an neonatal intensive care unit (NICU) in 1997 and 1998 compared with previous years, which coincided with increased incidence of nosocomial sepsis. Specific risk factors related to this NICU and a possible relationship between NEC and nosocomial sepsis were studied retrospectively, including all patients with NEC since 1990 and matched controls. Methods: Clinical and bacteriological data from the period before the development of NEC and a similar period for the controls were collected retrospectively and corrected for birthweight and gestational age. Statistical analysis was performed by a stepwise regression model. Results: Data of 104 neonates with NEC and matched controls were analysed. The median day of onset of NEC was 12 d (range 1-63 d). Significant risk factors for NEC were: insertion of a peripheral artery catheter [odds ratio (OR) 2.3, 95% confidence interval (95% CI) 1.3-3.9] and a central venous catheter (OR 5.6, 95% CI 3.1-10.1), colonization with Klebsiella sp. (OR 3.4, 95% CI 1.5-7.5) and Escherichia coli (OR 2.1, 95% CI 1.0-4.5), and the occurrence of sepsis, in particular due to coagulase-negative staphylococci (OR 2.6, 95% CI 1.4-5.1). The risk for NEC was decreased after the early use ( Conclusion: Insertion of central venous and peripheral arterial catheters is positively associated with NEC, as is colonization with the Gram-negative bacilli Klebsiella and E. coli and the occurrence of sepsis, particularly due to coagulase-negative staphylococci. Early treatment with amoxicillin-clavulanate and gentamicin is negatively associated with NEC and may be protective against NEC.