Issue: June 2020
Disclosures: The authors report no relevant financial disclosures.
May 06, 2020
2 min read

Rise in infant Cronobacter infections linked to powdered formula

Issue: June 2020
Disclosures: The authors report no relevant financial disclosures.
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Reported cases of invasive Cronobacter infection rose significantly in recent years, with opened containers of contaminated powdered infant formula most commonly identified as the source of the infections, researchers reported recently in Emerging Infectious Diseases.

Jonathan Strysko

Globally, there were 8.7 cases of Cronobacter per year between 2004 and 2018, up from 1.2 cases per year from 1961 to 2004, according to Jonathan Strysko, MD, and colleagues from the CDC, who reviewed all cases reported to the agency and documented in the literature during those 50-plus years.

The findings “reaffirm the need to promote safer alternatives for infant feeding, particularly among neonates,” the researchers said. These alternatives “include direct breastfeeding, feeding with breastmilk that has been expressed safely and feeding with liquid formula that has been safely handled and stored,” they wrote.

“Although novel modes of transmission, like contaminated expressed breast milk, have been anecdotally reported in recent years, contaminated powdered infant formula from opened containers remains the most commonly identified transmission vehicle for Cronobacter,” Strysko told Healio.

“Even if contamination does not occur during production, powdered formula can easily become contaminated once containers are opened and exposed to the environment. Although vigilant adherence to best hand-hygiene practices is critical when handling and preparing formula, we also believe engineering solutions like redesigned packaging could help prevent transmission of Cronobacter and other pathogens.”

Strysko and colleagues reviewed 183 cases from 24 countries on six continents from 1961 to 2018, including 79 that were reported in the United States. Among 102 infants for whom feeding histories were described, 79% had recently consumed powdered infant formula (PIF), with or without other supplemental feeding types, whereas 47% solely consumed PIF.

Overall, 63% (n = 116) of infants had Cronobacter meningitis, whereas the rest had isolated bacteremia. Patients with Cronobacter meningitis were more likely to have experienced onset outside of the hospital.

“For several years, public health officials at CDC have been noticing a number of Cronobacter cases occurring among nonhospitalized and full-term infants, so we were not surprised to see this trend reflected in the aggregate data,” Strysko said. “We suspect that the 2002 FDA recommendation discouraging the use of powdered infant formula among hospitalized infants in the United States has likely helped prevent some cases among hospitalized and preterm infants.”

Sixty-seven percent of patients were neonates, and 38% died. Patients who did not die had complications, such as cerebral abscess or infarction (27%) and hydrocephalus (16%).


“Our findings provide continued evidence to show that invasive Cronobacter infections, including bloodstream infections and meningitis, disproportionately affect infants in the neonatal period and are associated with devastating neurological disabilities and mortality as high as 38%,” Strysko said. “Clinicians familiar with Cronobacter — formerly known as Enterobacter sakazakii — might be inclined to associate it with hospitalized and premature infants only, but our findings suggest a rising majority of cases occur among nonhospitalized and full-term infants in the United States. Most had no underlying conditions.”

Strysko said clinicians who encounter infants with a Cronobacter infection “should delve deeper into the infant’s recent feeding history and immediately contact their local health department to determine if a larger investigation is warranted.”