• Extraordinary Circumstances

Infant botulism is normally sporadic; most cases involve one infant, one household, and no single identified commercial source. Bacterial spores are widely present in soil and dust around the country and therefore may cause sporadic, random infections. A multistate outbreak of infant botulism tied to a manufactured infant formula is therefore unusual. The Centers for Disease Control and Prevention (CDC) and the US Food and Drug Administration (FDA) concluded that epidemiologic and laboratory evidence showed ByHeart Whole Nutrition infant formula was contaminated with C. botulinum and made infants sick. Outbreaks like this have, historically, been uncommon.^[1] According to the FDA, this is the first known botulism outbreak tied to infant formula anywhere in the world since the condition was first described about fifty years ago.^[2]

• The Outbreak Summary

In October 2025, California’s Infant Botulism Treatment and Prevention Program noticed that three infants with suspected infant botulism had all been fed the same powdered formula. State officials alerted the CDC, and a multistate investigation followed. The case total was revised as the investigation widened, the case definition was expanded to capture earlier illnesses, and some early-suspected cases were later reclassified.^[3]

Feature	Summary
Product	ByHeart Whole Nutrition powdered infant formula (cans and single-serve “Anywhere Pack”); on sale nationwide since March 2022
Case Count (final)	48 infants — 28 confirmed and 20 probable. Reduced from an interim 51 infants after record review applied additional case-definition criteria and three cases from three states were diagnosed with other illnesses and excluded (review completed Feb. 26, 2026)
Locations (17 states)	AZ, CA, ID, IL, KY, MA, MI, MN, NC, NJ, OR, PA, RI, TX, VA, WA, WI
Outcomes	All 48 infants hospitalized and treated with BabyBIG; no deaths reported
Illness Onset	December 24, 2023 – November 29, 2025 (most clustered August–November 2025)
Investigation Status	CDC declared the outbreak over on February 26, 2026; no new cases added since December 10, 2025
Toxin Type	Both toxin type A and type B recovered from outbreak cases. The strains that matched clinical isolates by whole-genome sequencing were type A (subtype A1), although ByHeart’s own testing also reported type B in finished product and in the whole-milk powder; the unusual appearance of a type A strain in locations where type B strains normally dominate was a key outbreak signal
Laboratory Evidence	C. botulinum detected in infant formula (multiple lots), in opened and closed formula samples, in the base mix, and in the organic, whole-milk powder ingredient; whole-genome sequencing (WGS) has identified 17 distinct strains across patient, product, and ingredient samples
Source	Whole-genome sequencing links the outbreak pathogen across clinical, formula, base-mix, and ingredient samples, with strong matches to organic, whole-milk powder supplied to ByHeart; as of Feb. 26, 2026, the FDA had not yet determined a single root cause and the investigation continues
Recall	Two lots of formula were recalled on Nov. 8, 2025; all ByHeart products were recalled on Nov. 11, 2025
Significance	Per the FDA, this is the first identified botulism outbreak tied to infant formula since infant botulism was first described ~50 years ago

Sources: See note 36, infra.^[4]

•  
  • The Investigation (FDA/CDC, February 26, 2026)

The FDA and CDC—in collaboration with the California Department of Public Health (CDPH), the Infant Botulism Treatment and Prevention Program (IBTPP), and other state and local partners—investigated the multistate infant botulism outbreak and concluded that ByHeart Whole Nutrition infant formula was its source. On February 26, 2026, the CDC declared the outbreak over. 

Public health officials reviewed the medical records of the 51 infants initially included in the investigation and applied additional case-definition criteria; no new cases have been added since December 10, 2025, and three previously reported cases from three states were ultimately diagnosed with other illnesses and excluded. The final case count is 28 confirmed and 20 probable cases of infant botulism—48 in all—with all 48 infants hospitalized, no deaths reported, and the last known illness onset on November 29, 2025.^[5]

Cases were reported across seventeen states: Arizona, California, Idaho, Illinois, Kentucky, Massachusetts, Michigan, Minnesota, North Carolina, New Jersey, Oregon, Pennsylvania, Rhode Island, Texas, Virginia, Washington, and Wisconsin.^[6]

Whole-genome sequencing tied patients, finished product, and ingredients together to the outbreak. As of February 26, 2026, two isolates from one lot of organic, whole-milk powder—collected by the FDA at Dairy Farmers of America, the processor for Organic West Milk, which supplied ByHeart—matched a cluster of clinical and food isolates that the FDA had first reported on January 23, 2026. That cluster also included an unopened powdered-formula sample tested by ByHeart; a closed, powdered-formula sample tested by the New York State Department of Health, Wadsworth Laboratory; one clinical isolate; and three isolates from one lot of organic, whole-milk powder tested by ByHeart.^[7]

Additional clinical isolates analyzed by CDPH matched clusters including product-samples: One clinical isolate matched a cluster that now includes three clinical isolates and an opened powdered-formula sample (tested by CDPH and reported positive on November 18, 2025). A second clinical isolate matched a cluster that now includes one clinical isolate, four isolates from one lot of powdered formula tested by ByHeart, and one sample of the base mix, used to make the powdered formula, tested by ByHeart.^[8]

The FDA has cautioned that testing for C. botulinum in infant formula and its ingredients is complex. To date, WGS has identified 17 different strains of the bacterium across patient, finished-product, and ingredient samples. While those results add to the evidence needed to investigate the outbreak’s origin, the FDA stated that, given the complexities of C. botulinum and the limited scientific evidence currently available, it has not yet determined a root cause of contamination, and that additional analysis and research is necessary. The agency has transitioned from its initial emergency response to post-incident surveillance, prevention, and compliance activities while continuing to investigate the root cause.^[9]

• Suspected Source

Milk and milk powder is the suspected root cause. Investigators detected C. botulinum type A in finished ByHeart formula, and the New York State Wadsworth Center reported that WGS of an isolate from a sample of the organic, whole-milk powder—collected at a processor supplying ByHeart—matched the strain from the finished formula and from a sick infant. Contaminated milk powder used as an ingredient is the leading explanation for how the pathogen contaminated the product, even though, as noted above, the FDA has not formally declared a single root cause as of its February 26, 2026 update. The full source investigation remains ongoing.^[10]

Because spores can be unevenly distributed through a batch of powder, not every infant who consumed the contaminated formula became ill. All infants were nonetheless considered at risk, which is why every ByHeart product was recalled and parents were urged to stop using it and to discard it.^[11]

• Why Formula—Normally So Safe—Was Vulnerable Here

Powdered infant formula is not sterile. The pathogens usually watched for (such as Cronobacter and Salmonella) do not form spores and are killed by pasteurization. Spore-forming bacteria, like C. botulinum, are different: their heat-resistant spores can survive normal processing. The 2025 event prompted the FDA and international food-standards bodies to begin a formal risk assessment of spore-forming organisms in powdered infant formula.^[12]

The literature establishes both the historical rarity of C. botulinum in commercial dried milk and formula, and the singular significance of the 2025 outbreak:

• Until 2025, C. botulinum was essentially never found in commercial dried milk or formula. Dedicated surveys—including nonfat dry milk, evaporated milk, and canned formula—historically tested negative.^[13]
• The 2025 ByHeart outbreak is the turning point and the strongest evidence of milk-powder risk to date. Whole-genome sequencing tied type A C. botulinum in organic, whole-milk powder to the strain in finished formula and to the strain in sick infants across multiple states—a tight genetic match across ingredient, product, and patient.^[14] [15]
• Earlier formula links were single cases with caveats. A 2001 United Kingdom case and a 2023 Chinese investigation each recovered the organism from formula milk powder, but causation was never firmly proven.^[16]
• Fluid and raw milk can carry the organism and toxin in the case of bovine botulism, and these spores also survive pasteurization, although pasteurization strongly degrades pre-formed toxin.^[17]

Related findings in soft, high-moisture dairy products, such as Italian mascarpone cheese, and in raw milk during herd botulism confirm that C. botulinum can and does contaminate a dairy matrix when conditions allow.^[18] The studies significant to the link between botulism and milk/formula, beyond the current outbreak, are summarized below:

Source	What was tested	Key finding
Harris et al., Front. Microbiol., 2026 (USA)	Unopened formula containers and bulk “base powder” (formula before packaging)	C. botulinum found in both finished product and base powder, even where the usual indicator organism was non-detectable, so standard screening would have missed it.
Brett et al., J. Med. Microbiol., 2005 (UK, 2001 case)	14 home foods from a 5-month-old with infant botulism	Type B C. botulinum recovered from an opened can of infant formula milk powder; two product isolates WGS-matched the infant’s isolate. The link was never definitively proven.
Luo et al., Chinese J. Food Hygiene, 2023 (China)	30 batches of infant formula milk powder from a company tied to a botulism case	While toxin was not detected directly, C. botulinum (type B) was isolated from one batch of milk powder.
Barash et al., J. Pediatr., 2010 (USA)	30 patient-used formula samples and nine market-bought formulas	Clostridium spores in 17% of patient-used and 78% of market formulas—but none were C. botulinum (they were related Clostridium species).

Full citations for the studies above appear at notes 45–48, infra.^[19]

In short, across decades of surveys, the detection of C. botulinum in commercial dried milk or formula was possible but vanishingly rare until 2025. That consistently rare baseline is precisely what makes the widespread genetic evidence in this outbreak—milk powder to finished formula and base mix to sick infants—so indicative of the formula’s defective and adulterated condition, notwithstanding that the FDA has not yet announced the formal root cause. 

• Post-Outbreak Developments

Developments after the outbreak was declared over have reinforced that ByHeart’s formula was the vehicle of contamination and that a contaminated dairy ingredient was the likely source. The FDA completed its onsite inspections of ByHeart’s manufacturing facilities and reported that it did not identify any facility deficiency that could explain the root cause of the outbreak; the agency’s continuing root-cause investigation is instead focused on incoming ingredients, and in particular on the dairy supply chain. 

The FDA and ByHeart sampled dairy ingredients at Dairy Farmers of America — the processor for ByHeart’s supplier, Organic West Milk — and whole-genome sequencing showed that two isolates from a single lot of organic, whole-milk powder matched a clinical isolate and a finished-formula sample isolate. The absence of any facility-based explanation, coupled with the genetic linkage running from the milk-powder ingredient to the finished product to sick infants, points squarely to a contaminated dairy ingredient.^[20]

Significantly, in June 2026, the FDA and CDC opened a second multistate infant-botulism investigation. This one was linked to a different brand, Nara Organics Whole Milk Organic powdered infant formula, and involved four confirmed C. botulinum type A infections from California (two), Pennsylvania, and Washington, with illness onsets in April and May 2026. Laboratory testing has since confirmed Clostridium botulinum in an open can of Nara Organics formula that had been fed to one of the sick infants. That outbreak has since been declared over, and the sequencing results that accompanied its closeout are set out below. There is a further, troubling connection between the two brands. When ByHeart recalled its formula in November 2025, it did not simply direct affected families to generic alternatives; it affirmatively steered them to Nara Organics. In a November 11, 2025 Instagram post, ByHeart recommended Nara Organics products and offered ByHeart customers a 20% discount code “to help and support ByHeart families make a smooth transition to a new formula.” That post was later deleted. ByHeart has since maintained that the two companies are entirely separate and that it merely shared a discount code as a resource; but the practical effect was that families fleeing one botulism-linked formula were pointed toward a second formula drawing on the very same organic-whole-milk supply chain — a chain that would, months later, be tied to a second infant-botulism outbreak.^[21]

Nara Organics and ByHeart share the same dairy suppliers: Organic West Milk and its processor, Dairy Farmers of America. During the ByHeart investigation, Organic West Milk gave the FDA an incomplete customer list that failed to disclose that its milk was also being supplied to the manufacturer of Nara Organics formula. That two separate infant formula brands drawing from the same organic-whole-milk supply chain each became associated with type A infant botulism is powerful corroboration that the dairy ingredient — not some idiosyncratic feature of one manufacturer’s plant — is the common thread, and it strengthens the inference of source in the recent infant botulism outbreaks.^[22]

These events also underscore the outbreak’s gravity. The 2025 ByHeart event is the largest infant-botulism outbreak ever documented in the United States and the first botulism outbreak tied to infant formula anywhere in the world, and it has prompted an international response: at the FDA’s urging, the Codex Committee on Food Hygiene and the joint FAO/WHO expert body (JEMRA) undertook a formal risk assessment of spore-forming pathogens, including C. botulinum, in powdered infant formula. ByHeart, for its part, has stated that it will not resume production without a new C. botulinum-specific testing protocol applied to every dairy ingredient and every finished batch before release — an implicit acknowledgment that the controls in place during the outbreak could not detect the hazard.^[23]

The FDA has since gone further, issuing a formal warning to the entire industry. On July 13, 2026, the agency sent a letter to the infant formula industry — addressed to manufacturers, packagers, distributors, exporters, importers, and retailers involved in the manufacture or distribution of infant formula and infant formula ingredients — over the signature of Acting Deputy Commissioner for Food Donald A. Prater, DVM. The FDA framed the letter as a response to several serious public health events: the two multistate outbreaks of infant botulism linked to powdered infant formula, and a separate cereulide intoxication event traced to a contaminated formula ingredient. The agency wrote that these events highlight risks manufacturers should consider when selecting ingredients and ingredient sources, that the consequences of safety failures in this product category are severe and, in some cases, life-threatening, and that a manufacturer’s responsibility for safety and quality extends to every ingredient, every supplier, and every link in the supply chain.^[24]

The letter also confirms, in the agency’s own words, several facts central to this claim. The FDA states that the ByHeart outbreak was the first botulism outbreak definitively tied to infant formula in the United States since infant botulism was first described as a distinct clinical entity nearly fifty years ago. It states that its inspections of ByHeart’s manufacturing facilities led to the identification of Clostridium botulinum in organic whole milk powder used as an ingredient; that it inspected and collected samples at Dairy Farmers of America, the processor for Organic West Milk, which supplied ByHeart; and that two samples from one lot of organic whole milk powder matched a clinical sample and an infant formula sample by whole-genome sequencing. It states that its ongoing root-cause investigation is focused on ingredients and their production environments. And it confirms that Organic West Milk also supplied Nara Organics, which voluntarily recalled all lots of its powdered infant formula after the June 2026 outbreak.^[25]

The FDA further situates the botulism outbreaks within a broader pattern of ingredient-borne failure in this industry. Between December 2025 and February 2026, nearly 150 suspected and confirmed cases of cereulide intoxication — cereulide being a toxin produced by Bacillus cereus — were reported across ten countries and resulted in global recalls of contaminated infant formula, all traced to contaminated arachidonic acid (ARA) oil. The a2 Milk Company recalled certain batches of its imported powdered infant formula from the United States market on May 2, 2026, and on May 12, 2026 all ARA oil products from CABIO Biotech (Wuhan, China) became subject to FDA Import Alert 99-51, which provides for detention without physical examination of human food that appears to have been prepared, packed, or held under insanitary conditions resulting in chemical contamination. Taking these events together — two infant botulism outbreaks potentially linked to a shared dairy ingredient supplier, and a global contamination event linked to an ARA supplier — the FDA identified a pattern in which, in each case, the risks were introduced through the supply chain, and in each case the consequences fell on infants.^[26]

Most significant for present purposes, the letter states plainly what the FDA expects of a formula manufacturer with respect to the ingredients it buys. Reiterating its March 2023 letter to the powdered infant formula industry, the agency states that suppliers of raw materials or other ingredients that will not receive a lethal treatment at the infant formula manufacturing facility are an extension of the infant formula manufacturing process, and that this principle is the foundation of the regulatory framework governing infant formula manufacturing. Under 21 C.F.R. Part 106, manufacturers must maintain production and in-process controls at every stage from receipt of raw materials through distribution of finished product, including developing and enforcing ingredient specifications, quarantining and dispositioning ingredients that fail to meet those specifications, and conducting regularly scheduled audits to verify compliance with current good manufacturing practices and quality control procedures. Under 21 C.F.R. Part 117, manufacturers and their supply chain partners must implement a food safety plan that includes a hazard analysis, preventive controls, and, where applicable, a risk-based supply chain program requiring them to identify and evaluate hazards associated with raw materials and ingredients, approve suppliers, and conduct supplier verification activities such as onsite audits by qualified auditors. The letter separately reminds manufacturers of their obligation under section 424(b) of the Federal Food, Drug, and Cosmetic Act to develop, maintain, and implement a redundancy risk management plan, and instructs that the requirement be treated as a meaningful risk management tool rather than a paper exercise.^[27]

The FDA also directs manufacturers to stay abreast of recall notifications, outbreak investigations, and import alerts, which may serve as safety signals that an identified ingredient or supplier presents risk, and it warns that experience has shown that ignoring or downplaying such signals can lead to public health events that could have been avoided. The agency expects substantive oversight of suppliers — understanding where ingredients come from, how they are produced, what risks they may carry, and whether those risks are being effectively controlled — and expects manufacturers to act swiftly to assess and address the risk when a contaminated ingredient or supplier concern is identified, whether by the FDA or through the manufacturer’s own monitoring. Finally, the letter catalogs the scientific work the agency has set in motion since these outbreaks, acknowledging the difficulty of managing spore-forming microbes in formula ingredients and that there may be no single approach to doing so: support for the Codex Committee on Food Hygiene’s request for JEMRA scientific advice on C. botulinum and Bacillus cereus in powdered infant formula, covering every stage from primary production and packaging through reconstitution and including environmental monitoring programs; engagement with external researchers on the presence and control of C. botulinum on dairy farms and in milk and milk powders; engagement with Cornell University’s Pathogenic Spore Consortium on strategies and training to reduce spore-formers in milk; and a request that the International Commission on Microbiological Specifications for Foods revisit its publication on the usefulness of testing for C. botulinum in powdered infant formula and dairy-based ingredients in light of the recent outbreaks. Each of these steps is an acknowledgment that the controls in place when these infants were poisoned were not adequate to the hazard.^[28]

That scientific work has now begun to produce results. The joint FAO/WHO expert meeting convened in Rome from June 15 to 19, 2026, and issued its summary and conclusions in July 2026. The Expert Group formally added botulinum neurotoxin-producing clostridia to the priority list of hazards for powdered formula alongside Salmonella and Cronobacter — a list that had not previously included them — and concluded that dairy ingredients have been demonstrated as a vehicle for such spores resulting in contamination of powdered formula, with other potential sources of contamination requiring further investigation. It further found that these spores had been detected in powdered formula in the past but had not been definitively linked to infant botulism cases prior to 2025. The Expert Group directed that powdered formula manufacturers should implement supplier risk management programs addressing botulinum neurotoxin-producing clostridia, that control of these spores starts with on-farm practices, and that mitigation strategies can potentially reduce spores prior to drying. It also concluded that hygiene indicators such as Enterobacteriaceae monitoring do not replace or reduce the need for pathogen-specific testing during environmental monitoring — the precise failure documented in this outbreak, where C. botulinum was present in both finished product and base powder while the usual indicator organism was non-detectable. The Expert Group acknowledged that powdered formula production processes are not designed to eliminate these spores and that the low concentrations involved present real challenges for detection and enumeration; but that is an argument for controlling the hazard upstream, at the farm and at the ingredient, which is precisely what both the Expert Group and the FDA say was required, and what ByHeart’s own post-outbreak commitment to C. botulinum-specific testing of every dairy ingredient concedes was not being done. The Expert Group separately concluded that current consumer preparation recommendations, which were designed to reduce the risk posed by Salmonella and Cronobacter spp., may not be effective for the control of botulinum neurotoxin-producing clostridial spores. And it recommended that Codex revise the Code of hygienic practice for powdered formulae for infants and young children (CXC 66-2008) throughout to address these clostridia, add a section addressing steps during primary production that may reduce spore load, and expand the roles of governments, industry, and consumers to include additional on-farm practices to reduce spore loads on dairy ingredients destined for powdered formula production.^[29]

On August 27, 2026, the Centers for Disease Control and Prevention declared the Nara Organics outbreak over. It closed with four confirmed cases of infant botulism among infants in California, Pennsylvania and Washington who had consumed Nara Organics Whole Milk Organic Powdered Infant Formula, with illness onsets on April 20, May 17, May 20 and May 31, 2026. All four infants were hospitalized. No deaths were reported. CDC stated that epidemiologic, traceback and laboratory data showed that the formula was contaminated with Clostridium botulinum and made infants sick.^[30]

The finding that accompanied that closeout is the most consequential development in this record since the ByHeart outbreak was itself declared over. The FDA reported that whole genome sequencing of one clinical sample from an infant in the Nara Organics outbreak matched a clinical sample from an infant in the 2025 ByHeart outbreak, a powdered infant formula base sample collected during the ByHeart investigation, and four samples of unopened cans of ByHeart powdered infant formula. CDC described the same result in more general terms, stating that whole genome sequencing analysis linked a patient sample from this outbreak to a patient sample, product samples and an ingredient sample collected during the investigation of the 2025 ByHeart outbreak. The agency further confirmed through traceback that the Nara Organics lots linked to those illnesses were manufactured with milk supplied by Organic West Milk and spray dried by Dairy Farmers of America — the same suppliers of organic whole milk and organic whole milk powder implicated in the November 2025 ByHeart outbreak — and stated that the matching sequencing results, together with the supply chain commonalities, indicate a common source of contamination between the two outbreaks. CDC stated the traceback finding more broadly still, reporting that the infant formulas sold by both Nara Organics and ByHeart — not merely the Nara Organics lots linked to illness — were made with that milk and dried by that processor. The FDA stated that there is not yet sufficient evidence to determine whether the milk was contaminated before drying or during the drying process, and that its root cause investigation remains open.^[31]

Every counterpart in that match set is a ByHeart sample. The strain recovered from an infant who never consumed ByHeart formula is genetically indistinguishable from the strain in ByHeart’s base powder and in four sealed, unopened cans of ByHeart’s finished product. Three consequences follow for this claim. First, the recovery of the outbreak organism from unopened cans forecloses any suggestion that the contamination was introduced in the home, at retail, or after the seal was broken; the product left ByHeart’s control in a contaminated condition. Second, the second outbreak supplies an independent check on causation that cannot be attributed to anything peculiar to ByHeart’s own facility. The two infants were fed different brands, manufactured by different companies on different continents, in outbreaks seven months apart, and the only route between them is the dairy ingredient they shared. Third, the persistence of a single strain through that ingredient stream — across two manufacturers, and across the entire period of ByHeart’s recall and the closeout of its own outbreak — is the opposite of the isolated or incidental contamination a defendant would need to establish.^[32]

The FDA’s own internal closeout record, obtained under the Freedom of Information Act, confirms these conclusions in the agency’s words. FDA released the Executive Incident Summary prepared by its Coordinated Outbreak Response and Evaluation (CORE) Network for the ByHeart outbreak, CORE Incident No. 1350, dated May 1, 2026, together with the incident command records, the Human Foods Program whole-genome sequencing report of February 24, 2026, and the Health Hazard Evaluation of December 5, 2025.^[33] The summary concludes: “Epidemiological, laboratory and traceback evidence indicate that consumption of ByHeart powdered infant formula resulted in this multistate infant botulism outbreak. The outbreak strain was isolated from finished product ByHeart PIF, base powder mix and whole milk powder (ingredient). Whole genome sequencing matched strains in whole milk powder, finished powdered infant formula product, and an infant botulism clinical isolate.” It acknowledges that, “[e]ven though there are several hypotheses, investigational findings could not identify the source or root cause of contamination of the powdered infant formula.”^[34]

The record quantifies the product evidence. At least seventeen product samples tested positive for C. botulinum — eight finished-formula samples, four base-mix samples, and five whole-milk-powder samples — collected and analyzed by the FDA, CDC, state laboratories, and ByHeart’s contract laboratory. The FDA’s own 26 samples yielded two positives, a base-mix retain from Blendhouse Allerton, Iowa, and a powdered-milk retain from Dairy Farmers of America, Fallon, Nevada. Two of five samples analyzed at the New York State Wadsworth Center were positive: an unopened can collected from an Arizona case household, lot 206VABP/251481P2, and a second Dairy Farmers of America milk-powder retain. ByHeart’s own testing reported a total of twelve positive samples across finished product, base powder, and organic whole-milk powder, including toxin type A in finished lots 251131P2 and 251261P2, toxin type B in finished lot 252161P2, and toxin types A and B in the whole-milk powder. Seven cases reported exposure to lot 206VABP/251261P2, which tested positive for toxin type A and was sequenced. ByHeart also reported to the FDA that one of its positive lots bore a November 15, 2024 production date, establishing that contaminated formula had been manufactured and sold at least a year before the recall.^[35]

The Human Foods Program sequenced 37 C. botulinum isolates — sixteen clinical and twenty-one product — and sorted them into seventeen strains. Four of those strains link infants directly to product or ingredient. Strain 6: clinical isolates from California, Oregon, and Arizona match the opened formula can from a California case at a mean of seven SNPs. Strain 8: a California clinical isolate matches four ByHeart finished-product isolates and a ByHeart base-powder isolate at a mean of four SNPs. Strain 11: two FDA isolates from a Dairy Farmers of America milk-powder retain, three ByHeart whole-milk-powder isolates, a ByHeart finished-product isolate, the unopened Arizona can, and a New Jersey clinical isolate match one another at a mean of 7.5 SNPs. Strain 2: a ByHeart finished-product isolate from lot 251261P2 matches a second Dairy Farmers of America milk-powder retain at eight SNPs. The summary’s traceback finding is that “[s]ampling results confirmed contamination was present in finished product, base mix, and organic milk powder,” and that “[t]he distribution and comingling of ingredients likely contributed to the widespread nature of the contamination.”^[36]

The incident records also document what the FDA knew about ByHeart’s facilities and what it found there. Before the outbreak, the FDA’s February 2025 inspection of the Allerton, Iowa base-powder plant was classified Voluntary Action Indicated, with a three-item Form 483 citing an ingredient not held under conditions to prevent adulteration, failure to eliminate rodent harborage areas when rodent issues arose during 2024–2025, and inadequate floor monitoring where Cronobacter sakazakii had been confirmed; a 2022 inspection of the same plant cited insanitary conditions and inadequate written preventive controls and was followed by a regulatory meeting. During the outbreak inspection itself, the FDA issued a Form 483 at Allerton on January 22, 2026, for failure to have a qualified individual document corrective actions, failure to ensure all food-contact surfaces were cleaned and sanitized, and failure to review and evaluate the public health significance of process-specification deviations.^[37] Although the FDA has stated that none of these findings explains the root cause, they are the conditions under which the product was made. The investigators also recorded the epidemiological signal that prompted the response: ByHeart accounted for an estimated one percent of powdered infant formula sales in the United States, yet of the 36 infants treated with BabyBIG between August 1 and November 10, 2025 who had any powdered-formula exposure, fifteen — more than forty percent — had consumed ByHeart, which the FDA described as “highly unusual” and “a significant epidemiological signal.”^[38]

The record further shows that the FDA, not ByHeart, requested the recall. CORE held its first call with ByHeart on the evening of November 7, 2025 to request a voluntary recall of two lots; on November 10 the FDA requested recall of all lots within expiry, which ByHeart announced the following day. The FDA’s Health Hazard Evaluation records that on November 19, 2025, after ByHeart’s own testing found the organism in five of 36 unopened cans spanning three lots, the company “amended their recall press to remove exculpatory statements regarding sampling.”^[39] That evaluation, signed on December 5, 2025 by the Chief Medical Officer of the FDA’s Human Foods Program, classified the hazard as life-threatening and the probability of harm as likely to occur, concluding that contamination of ByHeart formula “presents a severe health hazard to infants consuming this product” and that the resulting illness “almost always requires medical intervention, with most affected infants needing hospitalization and many requiring intensive care or mechanical ventilation due to the risk of rapid respiratory failure or death.”^[40]

Finally, the record shows how the Nara Organics link was missed. On January 28 and February 3, 2026, CORE issued traceability assignments to six firms, whose identities the FDA redacted, that had received Organic West Milk lots of whole-milk powder that tested positive for C. botulinum, requesting all distribution of that powder to infant formula manufacturers over the prior two years. The result: “None of the firms identified any infant formula manufacturers as customers that were supplied whole milk powder.” Nara Organics formula had been on sale through Target and its own website since July 2025, squarely within that window, and the first Nara-associated illness began about eight weeks after the last of those assignments closed.^[41]

The record also fixes the reach of the outbreak in time. On December 5, 2025, CDC expanded the case definition back to March 23, 2022, the date ByHeart began manufacturing the formula. On December 10, 2025, the FDA and CDC updated their public postings to reflect that expansion: case counts had previously included only illnesses from August 1, 2025 onward, and under the expanded definition CDC and state partners identified ten additional cases with onsets from December 2023 through July 2025, all ten confirmed infant botulism with documented exposure to ByHeart formula. No cases were identified between March 2022 and December 2023.^[42] Those ten children fell ill during a period in which contaminated product was demonstrably on the market: ByHeart’s own testing found C. botulinum in a lot bearing a November 15, 2024 production date, and the recall, when it came, reached only lots “currently within expiry.” The infants sickened in 2023 and 2024 were therefore fed formula that was never recalled from production runs that were never tested and were counted as part of this outbreak only when the agencies looked backward.^[43]

Two limits on this evidence should be stated plainly, because they are limits of scope and not of causation. The FDA has not announced a root cause, and it has not determined whether the milk was contaminated before drying or during the drying process. That open question governs how responsibility is ultimately apportioned among ByHeart and its upstream suppliers. It does not bear on whether ByHeart’s formula was contaminated with C. botulinum when it was sold — which the sequencing of ByHeart’s own unopened cans and its own base powder establishes — and it does not bear on whether that formula made infants sick, which the FDA and CDC concluded in February 2026 and have not retreated from since.

Those two limits do not reach Dairy Farmers of America or Organic West Milk. The FDA collected retain samples of organic whole-milk powder at the Dairy Farmers of America plant in Fallon, Nevada, and two of those retains tested positive for C. botulinum type A. One matched, by whole-genome sequencing, ByHeart’s whole-milk powder, ByHeart finished formula, an unopened can from an Arizona case household, and a New Jersey infant’s clinical isolate; the other matched ByHeart finished formula from lot 251261P2, the lot most often reported by ill infants. The record describes the chain: liquid whole milk from twenty dairies is delivered to Dairy Farmers of America, where it is spray-dried into organic whole-milk powder; Organic West Milk, acting as broker, delivers that powder by third-party carrier to Blendhouse Allerton, where it is incorporated into the base mix for ByHeart formula.^[44] Whether the spores entered the milk on the farm, in transit, or at the dryer is a question about origin, not about defect. The powder Dairy Farmers of America manufactured and sold contained viable C. botulinum; it was defective and unreasonably dangerous when it left that plant, and the manufacturer of a component that is itself defective is strictly liable for the harm the defect causes once the component is integrated into the finished product. Organic West Milk, as the seller that placed the powder into the stream of commerce and the supplier with which ByHeart contracted, stands in the position of any other commercial seller of a defective product. Neither is excused by the possibility that the raw milk carried the spores before it reached them; strict liability attaches to the condition of the product sold, not to fault in causing that condition. The FDA’s finding of no objectionable conditions at the Dairy Farmers of America plant, and its inability to determine whether contamination occurred before or during drying, bear on negligence and on apportionment among the defendants. They do not bear on whether the ingredient was defective, which the FDA’s own sampling established.^[45]

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^[1]           Harris, R. A., & Dabritz, H. A. (2024). Infant botulism: in search of Clostridium botulinum spores. Current Microbiology, 81(10), 306. https://link.springer.com/article/10.1007/s00284-024-03828-0

^[2]           U.S. FDA, Outbreak Investigation of Infant Botulism: Infant Formula (November 2025), https://www.fda.gov/food/outbreaks-foodborne-illness/outbreak-investigation-infant-botulism-infant-formula-november-2025; Contemporary Pediatrics, Infant botulism outbreak linked to powdered formula under FDA investigation, https://www.contemporarypediatrics.com/view/infant-botulism-outbreak-linked-to-powdered-formula-under-fda-investigation

^[3]           Khouri JM, et al., Multistate Infant Botulism Outbreak Associated with Powdered Infant Formula, NEJM Evidence (2026), https://evidence.nejm.org/doi/full/10.1056/EVIDpha2600020; CDC, Investigation Update: Infant Botulism Outbreak, November 2025 (final case data, Mar. 4, 2026), https://www.cdc.gov/botulism/outbreaks-investigations/infant-formula-nov-2025/investigation.html

^[4]           U.S. FDA, supra note 19; CDC, supra note 18; Khouri JM, et al., supra note 35; New York State Dept. of Health, Wadsworth Center, Biodefense Laboratory Identifies Contamination Source in Multistate Infant Botulism Outbreak (2026), https://www.wadsworth.org/news/wadsworth-center-biodefense-laboratory-identifies-contamination-source-multistate-infant. 

^[5]           CDC, Outbreak of Infant Botulism Linked to ByHeart Infant Formula — Food Safety Alert and Investigation Update (outbreak declared over Feb. 26, 2026), https://www.cdc.gov/botulism/outbreaks-investigations/infant-formula-nov-2025/index.html; U.S. FDA, FDA’s Actions to Respond to Clostridium botulinum Illnesses Associated with Consumption of Powdered Infant Formula (Feb. 26, 2026 update), https://www.fda.gov/food/outbreaks-foodborne-illness/fdas-actions-respond-clostridium-botulinum-illnesses-associated-consumption-powdered-infant-formula; FDA, Whole Genome Sequencing (WGS) Program, https://www.fda.gov/food/microbiology-research-food/whole-genome-sequencing-wgs-program. 

^[6]           CDC and U.S. FDA, supra notes 18–19.

^[7]           U.S. FDA, supra note 19.

^[8]           U.S. FDA and California Dept. of Public Health, supra note 19.

^[9]           U.S. FDA, supra note 19.

^[10]         U.S. FDA, supra note 19; New York State Dept. of Health, Wadsworth Center, supra note 36.

^[11]         CDC, supra note 18; U.S. FDA, supra note 19.

^[12]         U.S. FDA, FDA’s Actions to Respond to Clostridium botulinum Illnesses Associated with Consumption of Powdered Infant Formula, https://www.fda.gov/food/outbreaks-foodborne-illness/fdas-actions-respond-clostridium-botulinum-illnesses-associated-consumption-powdered-infant-formula ; Contemporary Pediatrics, supra note 34.

^[13]         Guilfoyle DE, Yager JF, Survey of infant foods for Clostridium botulinum spores, 66 J. Assoc. Off. Anal. Chem. 1302 (1983), https://pubmed.ncbi.nlm.nih.gov/6355058/; Barash JR, et al., Clostridial spores in powdered infant formula, J. Pediatr. (2010), https://www.jpeds.com/article/S0022-3476(10)00070-3/fulltext. 

^[14]         U.S. FDA, supra note 19; Harris RA, et al., Detection and characterization of Clostridium botulinum isolated from powdered infant formula, Front. Microbiol. (2026), https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2026.1800624/abstract. 

^[15]         Harris, R. A., & Dabritz, H. A. (2024). Infant botulism: in search of Clostridium botulinum spores. Current Microbiology, 81(10), 306. https://link.springer.com/article/10.1007/s00284-024-03828-0

^[16]         Brett MM, et al., A case of infant botulism with a possible link to infant formula milk powder, J. Med. Microbiol. (2005), https://pubmed.ncbi.nlm.nih.gov/16014431/ ; Johnson EA, et al., Characterization of Clostridium botulinum Strains Associated with an Infant Botulism Case in the United Kingdom, 43 J. Clin. Microbiol. 2602 (2005), https://pmc.ncbi.nlm.nih.gov/articles/PMC1151885 ; Luo H, et al., Isolation and typing of Clostridium botulinum from milk powder of an enterprise associated with a case of infant botulism, 35 Chinese J. Food Hygiene 1475 (2023), https://doaj.org/article/30d4cb5e20434fad9a47a75d7afcd132. 

^[17]         Böhnel H, et al., Presence of Clostridium botulinum and botulinum toxin in milk and udder tissue of dairy cows with suspected botulism, Vet. Rec. (2013), https://pubmed.ncbi.nlm.nih.gov/23585115/ ; Lindström M, et al., Clostridium botulinum in cattle and dairy products, 50 Crit. Rev. Food Sci. Nutr. 281 (2010), https://pubmed.ncbi.nlm.nih.gov/20301016/ ; The Case of Botulinum Toxin in Milk: Experimental Data, 76 Appl. Environ. Microbiol. 3293 (2010), https://aem.asm.org/content/76/10/3293.full. 

^[18]         Franciosa G, et al., Clostridium botulinum spores and toxin in mascarpone cheese and other milk products, 62 J. Food Prot. 867 (1999), https://pubmed.ncbi.nlm.nih.gov/10456738/; Aureli P, et al., An outbreak in Italy of botulism associated with a dessert made with mascarpone cream cheese, 16 Eur. J. Epidemiol. 913 (2000), https://pubmed.ncbi.nlm.nih.gov/11338122/ .

^[19]         Harris RA, et al., supra note 46 (C. botulinum present in finished product and bulk “base powder,” with genetic identity between a finished lot and a base powder, and detectable even where the usual indicator organism, sulfite-reducing clostridia, was non-detectable — such that standard screening would have missed it).

^[20]         U.S. FDA, Post-Outbreak Response Activities: Clostridium botulinum Illnesses Associated with Consumption of Powdered Infant Formula (onsite inspections of ByHeart facilities concluded; no facility deficiency identified that could explain the root cause; ongoing root-cause investigation focused on incoming ingredients and the dairy supply chain; WGS match between two isolates from one lot of organic whole milk powder sampled at Dairy Farmers of America and a clinical isolate and a positive finished-formula sample), https://www.fda.gov/food/outbreaks-foodborne-illness/post-outbreak-response-activities-clostridium-botulinum-illnesses-associated-consumption-powdered; see also After Infant Botulism Outbreak, FDA Shares Root Cause Analysis Findings from ByHeart Formula Plants, Food Safety Magazine (June 10, 2026).

^[21]         See Alison Young, ByHeart recommended its customers switch to Nara. Now a second infant formula is linked to botulism, Healthbeat (June 15, 2026), https://www.healthbeat.org/2026/06/15/nara-baby-formula-recall-botulism-cases-raise-safety-oversight-questions/ (ByHeart encouraged customers to switch to Nara Organics; a Nov. 11, 2025 ByHeart Instagram post recommending Nara products and offering a 20% discount code was deleted after the connection was reported); For Second Time in 7 Months, Baby Formula Linked to Infant Botulism Is Recalled, Truthout (June 2026) (ByHeart statement that the companies are “completely separate” and that it “shared a Nara discount code as a resource to help its customers find alternative options quickly”); see also New infant botulism outbreak puts fancy formulas under scrutiny, STAT (June 18, 2026) (noting ByHeart “directed customers to Nara during its recall last year, with Nara offering a 20% discount”).

^[22]         U.S. FDA, Outbreak Investigation of Infant Botulism: Powdered Infant Formula (June 2026) (initially three confirmed type A infant-botulism cases in California, Pennsylvania, and Washington linked to Nara Organics Whole Milk Organic powdered infant formula, onsets April–May 2026; Organic West Milk and its processor, Dairy Farmers of America, identified as suppliers shared with ByHeart; Organic West Milk’s earlier customer list to FDA was incomplete and omitted Nara Organics), https://www.fda.gov/food/outbreaks-foodborne-illness/outbreak-investigation-infant-botulism-powdered-infant-formula-june-2026; see also New infant botulism outbreak puts fancy formulas under scrutiny, STAT (June 18, 2026). The CDC’s investigation update, last revised July 6, 2026, reports four confirmed type A cases (California (2), Pennsylvania (1), and Washington (1)), all hospitalized and treated with BabyBIG, and states that laboratory testing detected Clostridium botulinum in an open can of Nara Organics formula fed to one of the infants, with the FDA testing an unopened can from the same lot. CDC, Investigation Update on Infant Botulism Outbreak, June 2026 (last updated July 6, 2026), https://www.cdc.gov/botulism/outbreaks-investigations/infant-formula-june-2026/investigation.html.

^[23]         Khouri JM, et al., Multistate Infant Botulism Outbreak Associated with Powdered Infant Formula, NEJM Evidence (2026); Codex Committee on Food Hygiene / FAO-WHO Joint Expert Meetings on Microbiological Risk Assessment (JEMRA) risk assessment of spore-forming pathogens, including C. botulinum, in powdered infant formula (undertaken at FDA’s urging); ByHeart, Inc., public statements regarding its post-outbreak Action Plan (new C. botulinum-specific testing protocol applied to every dairy ingredient and finished batch prior to release).

^[24]         Letter from Donald A. Prater, DVM, Acting Deputy Comm’r for Food, U.S. Food & Drug Admin., Human Foods Program, to Infant Formula Industry 1 (July 13, 2026), https://www.fda.gov/media/193534/download (letter directed to manufacturers, packagers, distributors, exporters, importers, and retailers involved in the manufacture or distribution of infant formula and infant formula ingredients; issued in response to two multistate outbreaks of infant botulism linked to powdered infant formula and to cereulide intoxication associated with a contaminated ingredient in infant formula; stating that FDA holds infant formula manufacturers to the highest standards of safety and quality and that this responsibility extends to every ingredient, every supplier, and every link in the supply chain).

^[25]         Id. at 1–2 (ByHeart outbreak was the first botulism outbreak definitively tied to infant formula in the United States since infant botulism was first described as a distinct clinical entity nearly 50 years ago; FDA’s inspections of ByHeart’s manufacturing facilities led to the identification of Clostridium botulinum in organic whole milk powder used as an ingredient; FDA inspected and collected samples at Dairy Farmers of America, Inc., the processor for Organic West Milk, which supplied ByHeart; two samples from one lot of organic whole milk powder matched a clinical sample and an infant formula sample by whole genome sequencing; FDA’s ongoing root-cause investigation is focused on ingredients and their production environments; Nara Organics voluntarily recalled all lots of its powdered infant formula and Organic West Milk also supplied Nara Organics).

^[26]         Id. at 2 (from December 2025 to February 2026, nearly 150 suspected and confirmed cases of cereulide intoxication reported across 10 countries, resulting in global recalls of infant formula contaminated with cereulide, a toxin produced by Bacillus cereus, traced to contaminated arachidonic acid (ARA) oil; the a2 Milk Company’s May 2, 2026 voluntary recall of certain batches of imported powdered infant formula from the U.S. market; FDA Import Alert 99-51 applied as of May 12, 2026 to all ARA oil products, including ARA oil powder, from CABIO Biotech (Wuhan, China); FDA’s conclusion that in each event the risks were introduced through the supply chain and the consequences fell on infants).

^[27]         Id. at 2–3 (reiterating FDA’s March 2023 Letter to the Powdered Infant Formula Industry that suppliers of raw materials or other ingredients that will not receive a lethal treatment at the infant formula manufacturing facility are an extension of the infant formula manufacturing process, and describing that principle as the foundation of the regulatory framework governing infant formula manufacturing; summarizing production and in-process control obligations under 21 C.F.R. Part 106 and food safety plan, preventive control, and supply-chain program obligations under 21 C.F.R. Part 117, including subpart G supplier verification; and citing the redundancy risk management plan requirement of section 424(b) of the FD&C Act, 21 U.S.C. § 350m(b), as added by the Food and Drug Omnibus Reform Act of 2022).

^[28]         Id. at 3–4 (recall notifications, outbreak investigations, and import alerts may serve as safety signals, and ignoring or downplaying them can lead to public health events that could have been avoided; FDA expects substantive supplier oversight and swift action when a contaminated ingredient or supplier concern is identified; describing FDA’s support for the Codex Committee on Food Hygiene’s request for scientific advice from the Joint FAO/WHO Expert Meeting on Microbiological Risk Assessment (JEMRA) regarding Clostridium botulinum and Bacillus cereus in powdered infant formula, its engagement with external researchers and with Cornell University’s Pathogenic Spore Consortium, and its request that the International Commission on Microbiological Specifications for Foods revisit its publication “Usefulness of testing for Clostridium botulinum in powdered infant formula and dairy-based ingredients for infant formula” in light of the recent U.S. infant botulism outbreaks).

^[29]         Joint FAO/WHO Expert Meeting on Microbiological Risk Assessment (JEMRA) on Powdered Formula for Infants and Young Children, FAO HQ, Rome, Italy, June 15–19, 2026, Summary and Conclusions (issued July 2026) (adding botulinum neurotoxin (BoNT)-producing clostridia and Bacillus cereus sensu lato (cereulide) to the priority hazard group for powdered formula; finding that dairy ingredients have been demonstrated as a vehicle for BoNT-producing clostridial spores resulting in contamination of powdered formula; finding that such spores had previously been detected in powdered formula but were not definitively linked to infant botulism cases prior to 2025; recommending supplier risk management programs addressing BoNT-producing clostridia; stating that control starts with on-farm practices and that mitigation strategies can potentially reduce spores prior to drying; stating that hygiene indicators such as Enterobacteriaceae monitoring do not replace or reduce the need for pathogen-specific testing during environmental monitoring; noting that current consumer preparation recommendations designed for Salmonella and Cronobacter spp. may not be effective against BoNT-producing clostridial spores; and recommending revisions to CXC 66-2008, including a primary production section addressing reduction of spore load and expanded on-farm practices for dairy ingredients destined for powdered formula production). The summary notes that a full report will be published by FAO and WHO, and its Annex 2 recommendations carry the disclaimer that they may be updated following availability of risk assessment results.

^[30]         Centers for Disease Control and Prevention, Infant Botulism Outbreak Linked to Powdered Infant Formula, June 2026, and its investigation, locations and timeline subpages, update of Aug. 27, 2026, https://www.cdc.gov/botulism/outbreaks-investigations/infant-formula-june-2026/index.html; investigation update at https://www.cdc.gov/botulism/outbreaks-investigations/infant-formula-june-2026/investigation.html (whole genome sequencing link, traceback findings, and statement that the outbreak is over).

^[31]         U.S. Food and Drug Administration, Outbreak Investigation of Infant Botulism: Powdered Infant Formula (June 2026), update of Aug. 27, 2026, https://www.fda.gov/food/outbreaks-foodborne-illness/outbreak-investigation-infant-botulism-powdered-infant-formula-june-2026; CDC, supra note 62.

^[32]         FDA, supra note 63; U.S. Food and Drug Administration, Post-Outbreak Response Activities: Clostridium botulinum Illnesses Associated with Consumption of Powdered Infant Formula, https://www.fda.gov/food/outbreaks-foodborne-illness/post-outbreak-response-activities-clostridium-botulinum-illnesses-associated-consumption-powdered (FDA and ByHeart sampling at Dairy Farmers of America; two samples from one lot of organic whole milk powder matched a clinical sample and a positive infant formula sample by whole genome sequencing; root cause investigation ongoing with a focus on ingredients).

^[33]         U.S. Food and Drug Administration, Coordinated Outbreak Response and Evaluation (CORE) Network, Executive Incident Summary: Clostridium botulinum/Infant Formula/Nov 2025, CARA #1350 (May 1, 2026), released with Incident Objectives (ICS 202, Operational Period #7), Incident Briefing (ICS 201, CORE Incident No. 1350), Human Foods Program Signal Detection & Bioinformatics Branch, WGS Analysis Report: WGS-Report-ByHeart-260224 (Feb. 24, 2026), and Human Foods Program Health Hazard Evaluation, HHE #11418, RES #97959 (Dec. 5, 2025), in response to FOIA Request No. 2026-4033 (redacted under 5 U.S.C. § 552(b)(4), (b)(5), (b)(6) and (b)(7)(D)) [hereinafter CORE Record].

^[34]         CORE Record, Executive Incident Summary at 11 (Conclusions).

^[35]         Id. at 5–7, 9–10 (Laboratory Sample Overview, Tables 1–4, and Traceback Abbreviated Summary); CORE Record, ICS 202, entry of Nov. 20, 2025 (ByHeart reported that its five positive samples corresponded to three lots, two of which were in the initial recall, and that the third lot code indicated a Nov. 15, 2024 production date).

^[36]         CORE Record, Executive Incident Summary at 8–10 (WGS analysis; Traceback Abbreviated Summary); see also CORE Record, WGS Analysis Report (Feb. 24, 2026) (phylogenetic clusters 1 through 4).

^[37]         CORE Record, ICS 201 at 5–6 (Firm Summary); Executive Incident Summary at 3 (Field Investigations & Findings, assignment 1); ICS 202, Operational Period #6 (entry of Jan. 22, 2026).

^[38]         CORE Record, ICS 202 (General Situational Awareness).

^[39]         CORE Record, ICS 201 at 5 (Incident Overview and Early Actions Timeline); ICS 202, entries of Nov. 7–11, 2025; Health Hazard Evaluation, HHE #11418, at 1–2 (Nature of Problem).

^[40]         CORE Record, Health Hazard Evaluation, HHE #11418, at 3–4 (Items 10–11 and Conclusion) (signed by CAPT Steven M. Grube, MD, MPH, Chief Medical Officer and HHE Board Chair, Human Foods Program, Dec. 5, 2025).

^[41]         CORE Record, Executive Incident Summary at 4–5 (Field Investigations & Findings, assignments 7–12); ICS 202, entry of Jan. 28, 2026 (“None of the firms identified any infant formula manufacturers as customers that were supplied whole milk powder.”); FDA, supra note 63 (Nara Organics formula distributed through Target retail stores, Target.com, and Nara.com between July 2025 and June 2026).

^[42]         CORE Record, ICS 202, entries of Dec. 5, 2025 (case definition expanded to March 23, 2022; ByHeart began manufacturing on that date) and Dec. 10, 2025 (ten additional confirmed cases, Dec. 2023 through July 2025; none between March 2022 and Dec. 2023); Executive Incident Summary at 2 (case definition covering onsets between December 2023 and February 2026; onset range Dec. 24, 2023 to Nov. 29, 2025).

^[43]         CORE Record, ICS 202, entries of Nov. 10–11, 2025 (FDA request and ByHeart recall of “ALL LOTS of ByHeart Powdered Infant Formula currently within expiry”) and Nov. 20, 2025 (Nov. 15, 2024 production date in the batch code of a positive lot); see also Executive Incident Summary at 10 (Product & Firm Actions).

^[44]         CORE Record, Executive Incident Summary at 3–6, 8–9 (assignments 3–5; Tables 1–2; WGS strains 2 and 11; Traceback Abbreviated Summary); ICS 202, entries of Nov. 25, 2025 (traceback records: liquid whole milk supplied by twenty dairies to Dairy Farmers of America, Fallon, Nev., where it is spray-dried into organic whole-milk powder; Organic West Milk acts as a broker and uses a third-party carrier to deliver the powder to Blendhouse Allerton, where it is incorporated into the base mix), Jan. 21, 2026 (FDA firm call informing Dairy Farmers of America, ByHeart, and Organic West Milk of the positive sample and whole-genome sequencing results), and Feb. 9, 2026 (FDA firm call with Dairy Farmers of America and Organic West Milk on FDA Sample #1319424).

^[45]         Restatement (Third) of Torts: Products Liability § 5 (1998) (one engaged in the business of selling a component is subject to liability for harm caused by a product into which the component is integrated if the component is itself defective and the defect causes the harm); id. § 2(a) (a product contains a manufacturing defect when it departs from its intended design even though all possible care was exercised in its preparation and marketing); Restatement (Second) of Torts § 402A & cmt. f (1965) (rule applies to any person engaged in the business of selling products for use or consumption, including any wholesale or retail dealer or distributor); see also CORE Record, Executive Incident Summary at 4 (assignment 4: full preventive-controls inspection at Dairy Farmers of America found no objectionable findings); FDA, supra note 63 (not enough evidence to determine whether the milk was contaminated before drying or during the drying process).