Cronobacter Support
03-04-2009, 02:24 PM
2.2 Rationale behind recommendations
2.2.1 Choice of infant formula
Infant formula should be selected based on the medical needs of the infant.
Where feasible, sterile liquid infant formula should be used in care settings, especially when feeding high-risk infants. These feeds do not contain harmful bacteria. Care settings, such as neonatal intensive care units, provide care for infants at greatest risk of E. sakazakii infection, i.e. neonates and those less than two months of age. However, sterile liquid infant formula is not always available (e.g. for infants who have special dietary needs), and PIF might be used instead.
2.2.2 General requirements
The preparation of feeds in institutions such as hospitals should be carefully controlled. This is because large volumes of feeds may need to be prepared, and the infants consuming feeds in these settings may be at particular risk of infection.
In order to help control the preparation of feeds from PIF, a dedicated area for preparation and storage of feeds should be provided to reduce the risk of cross-contamination with harmful bacteria. Each institution should
establish written guidelines for the preparation and handling of feeds prepared from PIF, the implementation of which should be monitored. This ensures consistent and safe handling. Full training should be given to staff preparing feeds, so that they understand the risks involved with PIF and know what steps to take to ensure these risks are reduced or controlled.
2.2.3 Good hygienic practice
Poor hygiene has been reported as the probable cause of some E. sakazakii outbreaks (Forsythe, 2005). The person preparing the feed should clean and disinfect the preparation surface and wash hands with soap and water before preparing a feed. This is because harmful bacteria can be carried on hands and can also be present on surfaces. Washing hands and cleaning and disinfecting surfaces reduces the risk of feeds becoming contaminated during preparation.
Hands must also be washed after using the toilet and after diaper changing because harmful bacteria, including E. sakazakii (Drudy et al., 2006), have been found in the urine and stools of infants. These bacteria can easily be carried on the hands and contaminate feed during its preparation.
2.2.4 Cleaning and sterilizing feeding and preparation equipment
Outbreaks of E. sakazakii infection have been attributed to equipment used for preparing feeds (Gürtler et al., 2005). E. sakazakii is widespread in the environment and has been shown to attach and grow (form 'biofilms')
on surfaces commonly used in infant feeding equipment, such as latex, silicon and stainless steel. It is therefore important that all infant feeding and preparation equipment (e.g. feeding cups, bottles, rings and teats) has been thoroughly cleaned and sterilized before use, since the formation of biofilms on such equipment may result in reservoirs of infection that can continually contaminate feeds (Iversen, Lane and Forsythe, 2004).
2.2.5 Temperature of reconstitution water
According to the FAO/WHO risk assessment (FAO/WHO, 2006), risk is dramatically reduced when PIF is reconstituted with water that is no less than 70 °C, as this temperature will kill any E. sakazakii in the powder. This level of risk reduction holds even if feeding times are extended (i.e. up to two hours), and even if ambient room temperature reaches 35 °C. Consequently, reconstituting PIF with water no less than 70 °C dramatically reduces the risk to all infants, even slow feeding infants and infants in warm climates where refrigeration for the prepared formula may not be readily available (e.g. developing countries).
When PIF is prepared with water that is less than 70 °C, it does not reach a high enough temperature to completely inactivate E. sakazakii present in the powder. This is a concern for the two following reasons: a) A small number of cells may cause illness, therefore it is important that cells present in the PIF are destroyed; and b) there is potential for surviving cells to multiply in the reconstituted formula. This risk is increased when the reconstituted formula is held for extended periods above refrigeration temperature.
Concerns have been raised over the use of very hot water for reconstituting PIF, but risk of E. sakazakii is only dramatically reduced when water at a temperature of no less than 70 °C is used (see Appendix 3). Currently, the instructions on many PIF products lead to PIF being reconstituted with water that is around 50 °C. But, according to the FAO/WHO risk assessment, reconstitution with 50 °C water generally results in the greatest increase in risk, unless the reconstituted formula is consumed immediately. Under no circumstances is risk reduced when PIF is reconstituted with 50 °C water. Manufacturer's instructions should be reviewed in the light of the findings of the risk assessment.
2.2.6 Volume of container for preparing batches
Often in care settings, a number of feeds are prepared in a single, large container, mixed and then transferred into bottles or feeding cups. Anecdotal evidence suggests that large volumes are prepared, and left to cool for long periods in the preparation container (refrigerated or not).
Preparation in larger containers increases the risk of infection, as: • the feed is more likely to become contaminated; and
• large volumes may take a long time to cool down, meaning that the formula remains for extended periods at a temperature that supports the growth of harmful bacteria.
The FAO/WHO risk assessment found that the use of larger containers (25 litre) for preparing and cooling feeds was associated with increased risk as a result of the slower cooling of formula, and therefore feeds should be cooled in small containers where possible.
2.2.1 Choice of infant formula
Infant formula should be selected based on the medical needs of the infant.
Where feasible, sterile liquid infant formula should be used in care settings, especially when feeding high-risk infants. These feeds do not contain harmful bacteria. Care settings, such as neonatal intensive care units, provide care for infants at greatest risk of E. sakazakii infection, i.e. neonates and those less than two months of age. However, sterile liquid infant formula is not always available (e.g. for infants who have special dietary needs), and PIF might be used instead.
2.2.2 General requirements
The preparation of feeds in institutions such as hospitals should be carefully controlled. This is because large volumes of feeds may need to be prepared, and the infants consuming feeds in these settings may be at particular risk of infection.
In order to help control the preparation of feeds from PIF, a dedicated area for preparation and storage of feeds should be provided to reduce the risk of cross-contamination with harmful bacteria. Each institution should
establish written guidelines for the preparation and handling of feeds prepared from PIF, the implementation of which should be monitored. This ensures consistent and safe handling. Full training should be given to staff preparing feeds, so that they understand the risks involved with PIF and know what steps to take to ensure these risks are reduced or controlled.
2.2.3 Good hygienic practice
Poor hygiene has been reported as the probable cause of some E. sakazakii outbreaks (Forsythe, 2005). The person preparing the feed should clean and disinfect the preparation surface and wash hands with soap and water before preparing a feed. This is because harmful bacteria can be carried on hands and can also be present on surfaces. Washing hands and cleaning and disinfecting surfaces reduces the risk of feeds becoming contaminated during preparation.
Hands must also be washed after using the toilet and after diaper changing because harmful bacteria, including E. sakazakii (Drudy et al., 2006), have been found in the urine and stools of infants. These bacteria can easily be carried on the hands and contaminate feed during its preparation.
2.2.4 Cleaning and sterilizing feeding and preparation equipment
Outbreaks of E. sakazakii infection have been attributed to equipment used for preparing feeds (Gürtler et al., 2005). E. sakazakii is widespread in the environment and has been shown to attach and grow (form 'biofilms')
on surfaces commonly used in infant feeding equipment, such as latex, silicon and stainless steel. It is therefore important that all infant feeding and preparation equipment (e.g. feeding cups, bottles, rings and teats) has been thoroughly cleaned and sterilized before use, since the formation of biofilms on such equipment may result in reservoirs of infection that can continually contaminate feeds (Iversen, Lane and Forsythe, 2004).
2.2.5 Temperature of reconstitution water
According to the FAO/WHO risk assessment (FAO/WHO, 2006), risk is dramatically reduced when PIF is reconstituted with water that is no less than 70 °C, as this temperature will kill any E. sakazakii in the powder. This level of risk reduction holds even if feeding times are extended (i.e. up to two hours), and even if ambient room temperature reaches 35 °C. Consequently, reconstituting PIF with water no less than 70 °C dramatically reduces the risk to all infants, even slow feeding infants and infants in warm climates where refrigeration for the prepared formula may not be readily available (e.g. developing countries).
When PIF is prepared with water that is less than 70 °C, it does not reach a high enough temperature to completely inactivate E. sakazakii present in the powder. This is a concern for the two following reasons: a) A small number of cells may cause illness, therefore it is important that cells present in the PIF are destroyed; and b) there is potential for surviving cells to multiply in the reconstituted formula. This risk is increased when the reconstituted formula is held for extended periods above refrigeration temperature.
Concerns have been raised over the use of very hot water for reconstituting PIF, but risk of E. sakazakii is only dramatically reduced when water at a temperature of no less than 70 °C is used (see Appendix 3). Currently, the instructions on many PIF products lead to PIF being reconstituted with water that is around 50 °C. But, according to the FAO/WHO risk assessment, reconstitution with 50 °C water generally results in the greatest increase in risk, unless the reconstituted formula is consumed immediately. Under no circumstances is risk reduced when PIF is reconstituted with 50 °C water. Manufacturer's instructions should be reviewed in the light of the findings of the risk assessment.
2.2.6 Volume of container for preparing batches
Often in care settings, a number of feeds are prepared in a single, large container, mixed and then transferred into bottles or feeding cups. Anecdotal evidence suggests that large volumes are prepared, and left to cool for long periods in the preparation container (refrigerated or not).
Preparation in larger containers increases the risk of infection, as: • the feed is more likely to become contaminated; and
• large volumes may take a long time to cool down, meaning that the formula remains for extended periods at a temperature that supports the growth of harmful bacteria.
The FAO/WHO risk assessment found that the use of larger containers (25 litre) for preparing and cooling feeds was associated with increased risk as a result of the slower cooling of formula, and therefore feeds should be cooled in small containers where possible.