Bacterial colonization patterns in neonates transferred from neonatal intensive care units

After an outbreak with Enterobacter cloacae we decided to routinely nurse all neonates in isolation who were transferred from a neonatal intensive care unit (NICU) to the neonatal unit of the Diakonessenhuis until cultures for MRSA and antibiotic-resistant Gram-negative bacteria were negative. The goal of this study was to determine (1) the colonization patterns with (antibiotic-resistant) bacteria; (2) whether there is a trend in time and (3) to identify predictors for colonization. Neonates from 2001 till 2006 transferred from a NICU to our neonatal unit were included. Patients were monitored for infections. In total 287 neonates were included. The average birth weight was 1990 g and gestational age 33 weeks and 3 days. Only one patient was colonized with a highly resistant microorganism (HRMO) and no MRSA was isolated. A NICU-stay longer than one week was the only independent risk factor for bacterial colonization. Twenty-six percent of neonates were colonized with bacteria resistant to amoxicillin/clavulanate. Five neonates (1.7%) developed a bacterial infection after transfer, none of them caused by an antibiotic-resistant microorganism present at transfer. No significant trends in time were found. In conclusion, we found a low prevalence of HRMO and a low incidence of bacterial infections in neonates after transfer from a NICU. There was no significant increase in time in the prevalence of colonization with (resistant) bacteria. A NICU-stay longer than a week was an independent predictor for colonization with bacteria. Based on these observations we have ended standard culturing and nursing in isolation of these patients.