The infant formula industry’s products are manufactured with strict adherence to Good Manufacturing Practices using high quality ingredients. All infant formula products, including liquid and powdered formulas, are extensively tested before release to assure that they meet the nutritional needs of infants and to assure the safety of the product, including microbiological quality with respect to Cronobacter spp. (formerly Enterobacter sakazakii). The products also are manufactured and tested to meet all Food and Drug Administration (FDA) bacteriological standards for infant formula as well as specifications established by the World Health Organization (WHO) and the Codex Alimentarius Commission. Consumers and health professionals can be assured that infant formula manufacturers’ products meet the highest microbiological standards and specifications.
In 2002, the FDA advised health professionals that E. sakazakii, a gram-negative, rod-shaped bacterium, had the potential to cause serious illness in premature and low birthweight infants and those with underlying medical conditions fed powdered infant formula.1 While there have been a few such cases reported, this is a very rare event.2 Furthermore, these illnesses have primarily occurred in hospital settings and were likely a result of inappropriate handling of powdered infant formulas.2 Given the large number of infants worldwide who consume powdered infant formula, the number of cases of illnesses due to Cronobacter spp. in powdered infant formula is very low.3
In hospital settings, commercially sterile liquid infant formula is recommended by the FDA as the preferred formula to be used because these formulas are heated to a high temperature at the end of the manufacturing process to destroy potentially harmful bacteria. Powdered infant formulas are also heat treated, but cannot be rendered sterile because of the technical requirements of the spray-drying process. In cases where health care professionals choose to use powdered infant formulas (e.g., for an infant's special nutritional needs), careful preparation and handling are essential. Guidelines for in-hospital preparation of powdered formulas must be closely adhered to by hospital staff, including immediately feeding or refrigerating prepared formula and feeding refrigerated formula within 24 hours of preparation.4 Minimizing the amount of time the reconstituted formula remains at room temperature, including “hang time” (the time when an enterally-fed formula is at room temperature in a feeding bag), to no longer than 4 hours for formula reconstituted from powder is also critical for limiting microorganism growth.4, 6 A recommendation from the World Health Organization (WHO) includes a shorter hang time. 5
Additionally, the WHO has recommended heating water to 70oC before adding the powdered formula.5 However, the FDA and others have expressed concerns that this high temperature not only could change the physical characteristics of the powdered product (such as causing clumping), cause glass bottle breakage, and destroy heat sensitive nutrients, but also presents danger of scalding to the preparer of the formula and to the infant.6, 7
Specific recommendations from the FDA and American Dietetic Association should be rigorously followed by hospitals to help ensure the microbiological integrity of powdered infant formula. These recommendations can be found here and here.
It should be noted that Cronobacter spp. can also be found throughout the environment, including in insects, soil, water, and in the home environment.8 The bacteria have been isolated from a wide range of food products other than powdered infant formula, including cheese, meat, milk, vegetables, fruits, grains, spices, and herbs.8 Careful preparation and handling of formula should also occur in the home to avoid contamination from the environment.
Updated December 2011
References Cited:
1. United States Food and Drug Administration. FDA warns about possible enterobacter sakazakii infections in hospitalized newborns fed powdered infant formulas. FDA Talk Paper. 2002. http://www.fda.gov/bbs/topics/ANSWERS/2002/ANS01146.html
2. Gurtler JB et al. Enterobacter sakazakii: a coliform of increased concern to infant health. Intl. J of Food Microbiology. 2005, 104: 1-34.
3. European Food Safety Authority. Review of the opinion on microbiological risks in infant formulae and followon formulae with regard to Enterobacteria as indicators. The EFSA Journal. 2007; (444), 1-14.
4. American Dietetic Association, Infant Feedings: Guidelines for Preparation of Formula and Breast Milk in Health Care Facilities. Pediatric Nutrition Practice Group of the American Dietetic Association, 2003.
5. World Health Organization. Safe preparation, storage, and handling of powdered infant formula Guidelines. 2007. http://www.who.int/foodsafety/publications/micro/pif_guidelines.pdf
6. United States Food and Drug Administration. Health Professionals Letter on Enterobacter sakazakii Infections Associated With Use of Powdered (Dry) Infant Formulas in Neonatal Intensive Care Units. October 10, 2002. http://www.cfsan.fda.gov/%7Edms/inf-ltr3.html
7. International Formula Council. International Formula Council Comments on the WHO Guidelines for the Safe Preparation, Storage and Handling of Powdered Infant Formula; 2007.
8. Friedemann, M. Enterobacter sakazakii in food and beverages (other than infant formula and milk powder). Intl. J of Food Microbiology. 2007, 116:1-10.