Cronobacter sakazakii is a pathogen found naturally in the environment that can enter manufacturing facilities and home environments on hands, shoes, and other contaminated surfaces.
Cronobacter sakazakii is especially good at surviving in dry foods, like powdered infant formula, powdered milk, herbal teas, and starches. For most people it is harmless, but it can be life threatening for infants younger than two months, infants who are born prematurely, and for infants who have weakened immune systems.
Overview of recent Cronobacter sakazakii illnesses and contamination of powdered infant formula
Between September 2021 and February 2022, the U.S. Food and Drug Administration (FDA) received complaints about four cases of illness or death in infants who consumed powdered infant formula. After learning that each of these infants consumed powdered infant formula products manufactured by Abbott Nutrition in Sturgis, Michigan, the FDA initiated an onsite inspection at the facility and commenced an investigation that revealed insanitary conditions, including the presence of five different strains of Cronobacter sakazakii within the facility. However, those samples did not genetically match the available clinical isolates from the two case-patients for whom whole genome sequencing (WGS) results were available or any other clinical isolates in the limited number of Cronobacter sakazakii isolates in the National Center for Biotechnology Informatics (NCBI) database. And the two case-patients’ isolates didn’t match each other. While the FDA was unable to determine whether the infants became sick from the firm’s product or contamination by other means, these findings raised serious concerns about the safety of the powdered infant formula and other products produced at this facility. On Feb. 17, 2022, the FDA warned consumers not to use certain products manufactured at this facility. That same day, Abbott Nutrition issued a voluntary recall of certain infant formula products manufactured in Sturgis, Michigan, and temporarily ceased production to safeguard public health while corrective actions were taken.
Typically, the Centers for Disease Control and Prevention (CDC) receives 2-4 reports of severe Cronobacter infections in infants annually from health departments across the country. Public health investigations primarily link these infections to formula contamination during preparation. Although during recent investigations the FDA was unable to determine whether the infants became sick from contaminated product or contamination by other means, the agency has identified opportunities to enhance the safety of powdered infant formula, which are reflected in the strategy outlined below.
Outline of FDA’s strategy to help prevent future illnesses linked to consumption of powdered infant formula
Since the initial reports of Cronobacter infections in infants resulting in the Abbott, Sturgis recall and the subsequent infant formula shortage in 2022, there have been other instances of Cronobacter contamination in infant formula facilities and additional recalls. Throughout this time, the FDA has remained steadfast in its commitment to investigate and prevent these incidents, has made significant strides in remedying and strengthening supply chains, and has taken all necessary steps to help ensure events like these are never repeated. The protection of this vital food sector and safety of our most vulnerable population remains a priority effort for the agency. In November of 2022, the FDA shared its Strategy to Help Prevent Cronobacter sakazakii Illnesses Associated with Consumption of Powdered Infant Formula and subsequent constituent update where the agency outlined several key efforts to address the noted goals.
Through development and implementation of this strategy, the FDA seeks to:
- Broaden scientific knowledge and understanding of Cronobacter sakazakii and public health interventions for controlling it.
- Improve oversight of safe production of powdered infant formula.
- Enhance communications and engagement with industry, consumers, federal, state, local, and other public health partners about infant formula safety.
In furtherance of those goals, the agency is sharing the following updates as they relate to the areas identified below:
Collaborate with stakeholders to better understand best practices in the manufacturing of powdered infant formula and what could be done to enhance safety: The FDA continues to have ongoing collaboration with industry members, coalition groups, academia, and consumers/consumer groups, to discuss the prevention strategy and engage in dialogue to better understand manufacturing practices and enhance safety in production and preparation of powdered infant formula.
- The FDA convened meetings with infant formula manufacturers throughout January and February 2023 to discuss the strategy, learn more about what industry is doing to enhance safety, and hear their ideas for prevention. These were followed by additional meetings between FDA and industry in May 2023 to collaboratively discuss next steps.
- In March 2023, as part of the prevention strategy work, the FDA sent a letter to the powdered infant formula industry to share current safety information and called on the industry to take prompt action to improve processes and programs for the protection of our most vulnerable population.
Strengthen regulatory activities and current systems for effective oversight of powdered infant formula, including:
- Consider whether to establish a dedicated cadre of investigators to conduct infant formula inspections: The FDA is establishing a dedicated investigator cadre for conducting inspections of infant formula manufacturing facilities and hiring for the Office of Critical Foods is underway.
- Explore realigning staff across the Center for Food Safety and Applied Nutrition and the Office of Regulatory Affairs to better support regulatory oversight of infant formula: The FDA has proposed plans to reorganize and realign. Under the proposal, current and new staff will be aligned and concentrated on this work. Infant formula activities will be housed within the new Office of Critical Foods within the proposed Nutrition Center of Excellence and with continued support from the proposed Office of Microbiological Food Safety.
- Review and update the Infant Formula Compliance Program, as needed, to reflect current science on Cronobacter, and ensure investigators and compliance officers are equipped with the tools and resources needed to enable a consistent and comprehensive approach to inspections of infant formula manufacturing facilities and compliance activities: An updated Infant Formula Compliance Program, based on extensive research and collaborative feedback, has been drafted, is undergoing review, and is expected to be released shortly.
- Provide additional education/training to FDA regulatory staff on inspecting powdered infant formula manufacturing facilities: A training workshop was completed in early 2023. The workshop provided critical inspectional information for investigators and other appropriate staff, including updates from lessons learned during previous inspections. The FDA has significantly expanded and improved a required infant formula online training course for investigators and other appropriate staff to ensure every infant formula inspection is robust, thorough, and focused on the most critical aspects of the infant formula manufacturing process. The FDA is identifying new training where necessary and plans for recurring training programs are in development.
Review and update current guidance and rules applicable to the production of powdered infant formula, as appropriate: Guidance documents, reflecting feedback and requests from stakeholders, are currently being drafted and relevant rules are being reviewed. Partners will have the opportunity to review and provide feedback on these guidance documents. Plans for additional guidance documents are in discussion.
Evaluate current testing requirements and determine whether improvements might be appropriate to enhance the safety of finished product: The FDA is actively evaluating testing requirements for finished product. This will be addressed through review of regulatory requirements of infant formula that will be led by the Office of Critical Foods. Furthermore, FDA continues to work with Congress to seek legal authority through a variety of means to require firms to, among other things, notify the Agency of any product testing positive for Cronobacter.
Continue developing and improving communications for consumers about safe formula preparation and storage: The FDA is closely working with federal and state governmental partners, as well as industry representatives and pediatric groups, to provide relevant and accessible educational materials to consumers.
Work with federal, state, and local partners to strengthen the ability of public health officials and firms to identify and investigate illnesses of Cronobacter spp., including increased genomic surveillance, and support elevation of Cronobacter sakazakii infection among infants as a nationally notifiable disease: The FDA, in collaboration with CDC, supported the Council of State and Territorial Epidemiologists (CSTE) position on elevating Cronobacter to a nationally notifiable disease. With this support, the CSTE successfully passed this vote on June 29, 2023. Cronobacter notification will take effect the beginning of 2024, decisioned on a state-by-state basis. The FDA will support and work with states on these increased testing efforts. This additional source of clinical isolates, coupled with FDA's work to collect and sequence environmental and product samples, will increase available sequences in the NCBI database and help address scientific data gaps pertaining to Cronobacter.
Conduct and support research to help fill knowledge gaps in the scientific understanding of Cronobacter. The FDA is actively collaborating with the National Advisory Committee on Microbiological Criteria for Foods (NACMCF) and industry to address knowledge gaps, enhance understanding of and gain key insights on Cronobacter, and its control within production. An interim report addressing the first group of questions (Current prevalence and level of Cronobacter spp. contamination in powdered infant formula in the U.S. market, what is known about Cronobacter spp. in other foods and in the home environment, and the frequency with which these foods and environmental sources contribute to human infections) is in development.