A cluster of necrotizing enterocolitis in neonatal intensive care unit of one of the hospitals in Salerno, Italy

From January to May 2012, a cluster of 12 cases of necrotizing enterocolitis (NEC) occurred in the Neonatal Intensive Care Unit ofone of the Hospitals in Salerno, Italy. Six of twelve infants developed severe NEC (stage II – III). All cases, but one, were preterm ofless than 37 week gestation (91.7%); five cases (41.7%) had a very low birth weight (VLBW) less than 1,500 g and five between1500 g and 2500 g (Low birth weight - LBW). The main risk factors associated with NEC was central venous line. Klebsiellapneumoniae was isolated from the clinical samples of 10 cases, of which 9 (90%) were extended-spectrum β-lactamase (ESβL)producers. K. pneumoniae were also isolated from various sites of environmental samples, suggesting the causal role of this pathogen inthe development of NEC in addition to other risk factors.We describe an outbreak of NEC in a tertiary care neonatal unit, alongwith the case-control study performed and microbiological investigation to identify noninfectious and infectious risk factorspotentially involved in the outbreak.