Cluster of necrotizing enterocolitis in a neonatal intensive care unit: New Mexico, 2007
published online 13 October 2009.
Background
Although the cause of necrotizing enterocolitis (NEC) is unknown, infection control practices have been shown to play an important role in containing many outbreaks. We investigated the etiology of a cluster of NEC in a level 3 neonatal intensive care unit and monitored for new cases following the implementation of enhanced infection control measures.
Methods
Investigators performed a chart and laboratory review for neonates with a diagnosis of NEC during January 1, 2007, to February 13, 2007, to identify risk factors. Enhanced environmental cleaning, cohorting of infants and nurses, and increased attention to hand hygiene were instituted. Commercial feeding products in the unit were tested for bacterial contamination. Close monitoring for new cases continued for 2 months following the identification of the cluster.
Results
Eleven cases of NEC were identified during the study period. Patients had a median of 5 disease risk factors (range, 3-8). Four distinct pathogens were detected in blood or stool specimens from 4 different patients. One sample of human milk fortifier (HMF) tested contained a colony count of Bacillus cereus at the US Food and Drug Administration's upper microbiologic limit for contamination. Seven (65%) patients received HMF before symptom onset, and 9 (82%) patients received 1 or more types of liquid formula. Only 1 new case was identified during the period of close monitoring.
Conclusion
A microbiologic cause was not identified, and, although the cluster might have resolved spontaneously, enhanced infection control and changing batches of HMF might have played a role in controlling this outbreak.
aCenters for Disease Control and Prevention, Office of Workforce and Career Development, EIS Field Assignments Branch, Atlanta, GA
bNew Mexico Department of Health, Epidemiology and Response Division, Santa Fe, NM
cCenters for Disease Control and Prevention, National Center for Preparedness, Detection, and Control of Infectious Diseases, Division of Healthcare Quality Promotion, Atlanta, GA
Address correspondence to Aaron Wendelboe, PhD, assistant professor, Biostatistics and Epidemiology, University of Oklahoma Health Sciences Center, 801 NE 13th St, CHB 323, Oklahoma City, OK 73104.
The findings and conclusions in this report are those of the author(s) and do not necessarily represent the views of the Centers for Disease Control and Prevention.
No external funding sources were used for this investigation.
A. M. W. had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
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