FDA warns of infection risk in powdered infant formulas

Apr 15, 2002 (CIDRAP News) – The Food and Drug Administration (FDA), citing a risk of serious infections with Enterobacter sakazakii, has recommended that milk-based powdered infant formulas not be used in neonatal intensive care units (NICUs) unless there is no alternative.

The recommendation was issued in conjunction with a Centers for Disease Control and Prevention (CDC) report of a case in which the death of a newborn infant in Tennessee was linked with E sakazakii in powdered formula. Powdered formulas are widely used in NICUs, and several outbreaks of E sakazakii infection in NICUs worldwide over the last several years have been associated with powdered formulas, the FDA and CDC said.

"E. sabazakii is an emerging foodborne pathogen that can cause sepsis, meningitis, or necrotizing enterocolitis in newborn infants, particularly premature infants or other infants with weakened immune systems," the FDA said in a news release. However, the agency said it is not aware of any E sabazakii infections in healthy full-term babies at home.

In a letter to healthcare professionals, the FDA said that powdered infant formulas are not "commercially sterile products" because, unlike liquid formula products, they are not heated long enough to achieve sterility. "The FDA has become aware that a substantial percentage of premature neonates in neonatal intensive care units are being fed non-commercially sterile products," the letter states. In view of the recent epidemiologic findings, it continues, "FDA recommends that powdered infant formulas not be used in neonatal intensive care settings unless there is no alternative available."

The agency said that if powdered formula is the only option, the following precautions will reduce the risk of infection:

  • Reconstituting powdered formula with boiling water and refrigerating it before feeding (though this will cause some loss of water-soluble vitamins)
  • Preparing only a small amount of formula for each feeding
  • Minimizing the holding time before reconstituted formula, either chilled or at room temperature, is used
  • Minimizing the "hang time," when formula is in the feeding bag at room temperature, with a maximum of 4 hours

The CDC reported the Tennessee case in the Apr 12 issue of Morbidity and Mortality Weekly Report. It involved a baby that was born at 33.5 weeks of gestation and had fever, tachycardia, and neurologic abnormalities at the age of 11 days. Culture of the cerebrospinal fluid yielded E sabazakii, and the infant was treated with antimicrobials for meningitis but died 9 days later.

The meningitis case prompted enhanced case surveillance in the NICU. Investigators screened 49 infants and found, in addition to the confirmed infection in the index case, two suspected infections and seven colonizations. A cohort study to identify risk factors showed that the use of Portagen powdered infant formula (Mead Johnson Nutritionals, Evansville, Ind.) was the only factor significantly associated with infection or colonization. Cultures of Portagen from the batches used in the NICU during the study period subsequently grew E sabazakii, whereas water and environmental samples did not.

As a result of the outbreak, the hospital changed its principal formula for NICU patients from powder to a commercially sterile liquid preparation and reduced the maximum "hang time" from 8 to 4 hours, the CDC report says.

The Tennessee case was the first report of E sabazakii infection linked with infant formula in the United States to prompt the recall of a commercial product, the CDC said. Mead Johnson Nutritionals voluntarily recalled the batch of Portagen implicated in the investigation on Mar 29, 2002.

The CDC said a recent unpublished survey showed that 9 of 16 responding hospitals used powdered formulas in their NICUs. In its own list of recommendations for preparation of powdered formulas in NICU settings, the agency said formula should be discarded if not used within 24 hours after preparation. In addition, hospitals should have written guidelines available for responding to product recalls.

CDC. Enterobacter sabazakii infections associated with the use of powdered infant formula—Tennessee, 2001. MMWR 2002(Apr 15):51:14;298-300
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