The purpose of this study was to assess the temperature conditions in neonatal care units for the preparation and storage of infant milk formula (IMF) and infant feeding using bottles and continuous feeding syringes. Enterobacter sakazakii in IMF for feeding infants has been chosen as the subject of this study because of the high risk incurred by IMF manufacture without total microbial destruction and the high sensitivity and mortality rates of this population group. From IMF preparation till neonate feeding, time-temperature profiles of IMF samples were monitored and analysed. In order to show the health impact of this data, potential E. sakazakii growth was calculated. As IMF can be also contaminated with Salmonella, potential Salmonella growth was also calculated. However potential Enterobacter sakazakii growth data were only analyzed because of Enterobacter sakazakii and Salmonella spp data being close.The study of 25 neonatal care units in 15 hospitals showed that the final potential growth for bottles depended on different parameters: initial water temperature, room temperature where IMF was prepared, cold storage temperature and time, reheating temperature and time. One parameter was not usually enough to determine the final growth increment alone and a well controlled and high performance stage could result in an incorrect food safety indication if the other stages are less effective. On the other hand, the final potential growth for the continuous feeding syringes depended mainly on the feeding period since the IMF was kept in a particularly high ambient air temperature ( 25°C) in the infant's bedroom. This stage would be controlled first (with a cold syringe cover for example); then, as for bottles, the other stages would be controlled to result in a correct food safety indication.
Keywords: Risk factors; Predictive microbiology; infant milk formula, Enterobacter sakazakii
IntroductionEnterobacter sakazakii in infant milk formula (IMF) has been implicated in infant infections, especially among high-risk infants who are premature, have a low birth weight or are immunocompromised. The overall incidence of disease due to Enterobacter sakazakii is relatively low, with about 50 cases among 60 days old infants reported worldwide over the last 40 years (Iversen, Forsythe, 2003;Lehner, Stephan, 2004). Data on these infants indicated most of them were pre-terme, below 37 weeks gestation, and had a low birth-weight, below 2500 g, or peripartum complications (Lai, 2001). Mortality rates of 40 to 80% (Nazarowec-White, Farber, 1997a;Edelson-Mammel, Buchanan, 2004) have been reported. Survivors often suffer from serious brain damage such as hydrocephalus, quadriplegia and late neural development. Up until now, due to the limited information available on E. sakazakii exposure, the dose-response curve, probably with a linear relationship (Lehner, Stephan, 2004) Provided by manufacturers, these products are ready-to-use in liquid or powder forms. While all liquid forms are sterile, the microbial (mainly Enterobacter s...
