A widespread epidemic of mild necrotizing enterocolitis of unknown cause

C. L. Anderson, M. F. Collin, J. P. O'Keefe, M. Challapalli, T. F. Myers, C. C. Caldwell and G. S. Ahmed

Within a 28-day period, necrotizing enterocolitis (NEC) developed in 20 of 38 infants (53%). Patients with NEC were compared with the remaining 18 infants hospitalized at the same time who did not acquire the disease. Complications of pregnancy and labor-delivery and infant care practices did not differ between groups. Mean chronologic age was significantly different between patients with NEC and those without, 29 days v 77 days. Mean postconceptional age at the time of the outbreak was also significantly different, 33.4 weeks v 42.3 weeks. None of the cultures demonstrated a specific common pathogen. The low mortality (5%) and the large number of infants affected suggest an atypical out-break of NEC. We could not isolate a causative agent despite extensive epidemiologic investigation, and suggest that postconceptional age delineates those at risk.