Invasive Cronobacter infection, first reported in 1958, is a rare disease of infants. Liquefying meningitis, severe neurological impairment, and death are common complications. Over 80% of cases occur in infants ≤60 days of age and fed powder infant formula (PIF). The World Heath Organization (WHO) has stated: “Contaminated powdered infant formula has been convincingly shown, both epidemiologically and microbiologically, to be the vehicle and source of infection in infants.” The U.S. Food and Drug Administration (FDA) recently proposed revisions to its infant formula regulations (CGMP), including that an appropriate standard for Cronobacter spp. in final PIF products be negative in thirty 10-gram samples. The FDA assumes that the statistical design of its proposed sampling plan will provide a relative annual risk reduction of 20% fewer cases (assuming a mean log10 concentration of pathogen of -5 CFU/g) of illness from Cronobacter spp. than would be the case if there were no PIF sampling plan in place (71 FR 43392 at 43394-43395). The FDA notes that, if its underlying assumptions about Cronobacter PIF contamination are correct, "when the production aggregate is sampled and the composite is tested, if the pathogen is not detected, the manufacturer has a 95 percent level of confidence that there would be <1 CFU Cronobacter spp. in 100 g powder". In other words, this testing does not guarantee an absence of Cronobacter.

The proposed Frontiers Research Topic will provide articles concerning cutting-edge research on key issues related to invasive Cronobacter infections, including one or more articles concerning the evolving epidemiology of this disease and public health implications of the epidemiologic data. Other article(s) will present and discuss microbiologic research underway since Cronobacter's taxonomic reclassification. This research indicates that, with isolated exception(s), invasive infections are due to a small number of specific C. sakazakii strains. Virulence markers and factors, incubation period, and infectious dose will also be discussed.
The FDA and representatives of formula manufacturers have suggested that PIF is no longer a source of invasive Cronobacter infection and, rather, infections are due to home environmental contamination or person-to-person contact. They have not provided data to support this hypothesis and no source other than powdered formula has ever been epidemiologically linked to a case of invasive Cronobacter infection. Articles should therefore be included on the following topics: the spectrum of normal human skin and gastrointestinal flora; the prevalence of household, hospital, formula factory, and food factory contamination with various Cronobacter species; the reasons why powdered formula products are at risk of Cronobacter contamination; the characteristics of Cronobacter contamination in PIF; and the routine environmental and product testing recommended by the FDA and other health agencies. One or two articles might also be included concerning the knowledge, attitude, and behaviors of healthcare providers and parents related to: a) the microbiologic risks associated with various forms of infant nutrition and b) FDA and WHO's PIF preparation and feeding recommendations.

Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.