A multistate outbreak of infant botulism linked to ByHeart organic infant formula has reached unprecedented proportions, affecting at least 51 babies across 19 states as of early December 2025.
The outbreak marks the first documented case of Clostridium botulinum contamination in powdered infant formula in the United States, representing a rare and serious public health emergency that has prompted federal health authorities to expand protective measures nationwide.
Federal health officials announced the expansion on December 10, determining that the contamination may have impacted all ByHeart formula products since the company began manufacturing in March 2022.
The Centers for Disease Control and Prevention updated its case definition to include any infant diagnosed with botulism following exposure to ByHeart formula at any time since production commenced, a precautionary measure that uncovered an additional 12 previously unreported cases dating back to December 2023.
The outbreak was first disclosed publicly on November 8 when health officials initially reported 13 suspected or confirmed cases across 10 states. Cases began appearing in August 2025, with the most recent reported case on December 1.
All 51 hospitalized infants have received treatment with BabyBIG, a human plasma-derived antitoxin that neutralizes the botulism neurotoxin circulating in the bloodstream. Significantly, no deaths have been reported in connection with the outbreak.
Clostridium botulinum spores germinate within an infant's intestinal tract, producing a potent neurotoxin that causes progressive muscle weakness.
Symptoms emerge gradually and may take up to 30 days to manifest, beginning with constipation—often the first sign parents notice—followed by difficulty feeding, a weak cry, loss of head control, diminished facial expression, and in severe cases, respiratory failure. The delayed onset underscores the critical importance of parent vigilance and rapid medical intervention.
ByHeart, a New York-based formula manufacturer established in 2016, initiated its initial recall of two specific lots on November 8 following FDA recommendations. Holding approximately 1 percent of the U.S. infant formula market, the company distributed roughly 200,000 cans monthly before the recall.
On November 11, the company expanded its recall to encompass all ByHeart Whole Nutrition Infant Formula products regardless of lot number or size, including both standard cans and single-serve "Anywhere Pack" sticks.
Laboratory testing conducted by an independent contractor revealed that Clostridium botulinum was detected in five of 36 samples from three distinct lots. California health authorities independently confirmed the presence of botulinum toxin in an opened container of ByHeart formula fed to an infected infant.
However, as of the recall expansion, neither ByHeart nor federal authorities had identified the bacterium in any unopened cans, presenting a persistent puzzle regarding the contamination pathway.
The outbreak has triggered the largest investigation of its kind, with the FDA dispatching inspectors to ByHeart manufacturing facilities in Allerton, Iowa, and Portland, Oregon, to identify the contamination source.
Despite company statements denying that unopened products tested positive, federal investigators continue searching for answers in a production environment with a documented history of sanitary failures.
ByHeart's regulatory history reveals troubling patterns predating the botulism outbreak. In December 2022, the company recalled five batches of formula after samples tested positive for Cronobacter sakazakii, a bacterium capable of causing severe or fatal infections in infants. The contamination went undetected for months despite warning signs that should have triggered immediate investigation.
A subsequent FDA warning letter issued on August 30, 2023, cited significant violations of manufacturing practices and quality control procedures. Inspectors uncovered failures in the establishment of process controls designed to prevent microorganism contamination, inadequate temperature monitoring, and insufficient root cause analysis.
Records from FDA inspections disclosed numerous sanitary deficiencies at ByHeart facilities. The Reading, Pennsylvania production facility, which was shuttered in September 2023, contained mold in water tanks intended for clean water, thousands of dead insects in manufacturing areas, and recurring roof leaks that allowed outside water to enter production zones.
Staff failed to report temperature variations that circumvented critical microorganism kill steps, and affected product proceeded to be shipped despite these undocumented deviations. Water intrusion incidents occurred at least twice, and in one case, Cronobacter was detected in the processing environment immediately following a leak, yet ByHeart's root cause analysis dismissed the connection.
The company's response to the Cronobacter contamination revealed additional inadequacies. When a batch tested positive in October 2022, ByHeart initially retained only one lot for destruction while releasing others to consumers.
Following FDA intervention, the company conducted a voluntary recall of five additional lots from the same production period. The company's conclusion that positive test results represented laboratory error contradicted available evidence and drew FDA criticism.
States currently affected include Arizona, California, Idaho, Illinois, Kentucky, Massachusetts, Maine, Michigan, Minnesota, North Carolina, New Jersey, Ohio, Oregon, Pennsylvania, Rhode Island, Texas, Virginia, Washington, and Wisconsin.
The FDA has reported discovering recalled formula still available for purchase at major retailers including Walmart, Target, and Kroger as of late November, despite the ongoing recall efforts.
Families of affected infants have initiated legal action against ByHeart in federal courts across multiple jurisdictions. These lawsuits allege that the formula was defective and that ByHeart acted negligently in selling contaminated products to consumers.
Plaintiffs seek compensation for medical expenses, which can exceed $40,000 for BabyBIG treatment alone, as well as emotional distress and other damages related to hospitalization and long-term health impacts. The litigation framework invokes strict product liability doctrines, establishing that manufacturers bear responsibility for defective products regardless of intent.
BabyBIG, the only treatment for infant botulism approved in the United States, is produced exclusively by the California Department of Public Health's Infant Botulism Treatment and Prevention Program.
The treatment must be administered intravenously as soon as possible to achieve optimal outcomes, as early intervention reduces hospitalization duration and accelerates recovery. The antibodies provided by BabyBIG may remain in an infant's system for several months, though their maximum effectiveness extends approximately one month following administration.
Public health authorities have advised families to label any remaining ByHeart formula with "do not use" and store it safely for at least one month, as state health departments may require samples for continued investigation.
Surfaces and items that contacted the formula should be washed with hot, soapy water or run through a dishwasher. Retailers have been instructed to remove all ByHeart products from shelves, and the company has established a website to guide affected families through the refund process.
The CDC's rapid response to the outbreak, coordinated with ByHeart and state health departments, utilized real-time data evaluation to expand warnings and prevent additional exposures.
This first-ever documented outbreak of infant botulism linked to powdered formula has exposed significant gaps in the manufacturing oversight and quality assurance systems intended to protect the nation's most vulnerable population. The investigation continues as federal authorities work to establish the definitive source of contamination and implement corrective measures to prevent future occurrences.
