As of November 19, the number of infant botulism cases linked to consumption of ByHeart formula has grown to 31 across 15 states. ByHeart Inc. has recalled all lots of its infant formula products, sold in stores and online nationwide.

The California Department of Public Health’s (CDPH’s) Infant Botulism Treatment and Prevention Program (IBTPP) first notified federal public health agencies about a spike of infant botulism hospitalizations. IBTPP operates the only global source of infant botulism treatment worldwide. Subsequently, an investigation was launched by the U.S. Food and Drug Administration (FDA), the U.S. Centers for Disease Control and Prevention (CDC), CDPH’s IBTPP, and other state and local partners.

For 27 cases with illness onset information available, illnesses began between August 9 and November 13, 2025. All 31 infants were hospitalized. No deaths have been reported. Illnesses have been reported in: Arizona (three), California (four), Idaho (one), Illinois (two), Kentucky (one), Maine (one), Michigan (one), Minnesota (two), North Carolina (two), New Jersey (one), Oregon (three), Pennsylvania (one), Rhode Island (one), Texas (six), and Washington (two).

Preliminary laboratory test results from CDPH identified the presence of Clostridium botulinum in an open can of ByHeart infant formula (lot 206VABP/251131P2) that was fed to an infant with infant botulism. Additional testing of samples from outbreak patients are underway by several state agencies.

Additionally, FDA collected and is analyzing samples of unopened product. Analysis is ongoing and results will be provided as they become available. Additional testing is underway, and results are expected in the coming weeks.

FDA has received reports that recalled formula is still being found on store shelves in multiple states. FDA is working with state partners and retailers to ensure an effective recall. All ByHeart infant formula products have been recalled, and these products should not be available for sale in stores or online. This includes all formula cans and single-serve Anywhere Pack sticks.

Independent Testing by ByHeart Finds Clostridium botulinum in Product

On November 19, ByHeart posted a statement to its website confirming that, as a result of third-party testing by a contracted independent laboratory (IEH Laboratories and Consulting Group), Clostridium botulinum had been found in unused/unopened samples of ByHeart infant formula. The company says it is conducting a root cause analysis to determine the source of contamination, and that it is working with FDA to advance industry testing standards and safeguards for C. botulinum, for which it is not industry standard practice to test.

The new finding walks back the company's company’s earlier statements. ByHeart Inc. previously asserted that CDPH's preliminary test results were not enough to definitively link its product to the outbreak, saying that a positive sample from an open can of formula “lacks scientific basis to establish causation between the product and illness.” At the time, FDA underscored that detection of C. botulinum in infant formula is difficult, and a negative test result does not rule out the presence of the bacteria in the product.  

ByHeart Food Safety and Hygiene Failures Predating the Botulism Outbreak

According to FDA inspection reports and warning letters, ByHeart Inc. has a history of food safety and hygiene violations at its production facilities, including issues like mold, dead insects, and reoccurring roof leaks at its Reading, Pennsylvania facility, causing the plant to be shut down earlier in 2023.

Additionally, the firm received a warning letter from FDA in 2023 after a batch of finished product tested positive for Cronobacter sakazakii, prompting an investigation of the production facility. Not only did FDA find a roof leak in a production area, and lapses in Standard Operating Procedures (SOPs) and cleaning and sanitation verification activities that could allow microbiological contamination to occur, but the agency also reprimanded ByHeart for failing to conduct a comprehensive root cause analysis of the C. sakazakii contamination. In fact, ByHeart concluded from its root cause analysis that the C. sakazakii positive test result was a laboratory error—which FDA said was contrary to the evidence.

Update, November 20, 2025: The article has been edited to reflect the statement posted by ByHeart in the evening of November 19.

Update, November 26, 2025: ByHeart Inc. has found Clostridium botulinum Type A in five of 36 samples across three lots. “Based on these results, we cannot rule out the risk that all ByHeart formula across all product lots may have been contaminated,” said the company.

As of November 26, the number of infant botulism cases in the associated outbreak has grown to 37 across 17 states. Additionally, FDA has released ByHeart facility inspection reports from as early as 2022 showing a history of food safety breaches.

Update, December 3, 2025: A total of 39 infants with suspected or confirmed infant botulism and confirmed exposure to ByHeart Whole Nutrition infant formula (various lots) have been reported across 18 states. All 39 infants were hospitalized; no deaths have been reported.