ByHeart Inc., the formula manufacturer behind an ongoing infant botulism outbreak, has revealed that it found widespread contamination among unopened product samples, as 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.

ByHeart Finds Widespread Clostridium Botulinum Contamination in Product

ByHeart contracted an independent laboratory (IEH Laboratories and Consulting Group) to conduct product testing, which returned positive results for 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 in a November 24 statement.

The company also stated it is conducting a supply chain-wide root-cause analysis, which includes additional product testing.

Testing of opened product from patients’ homes is also underway by the U.S. Food and Drug Administration (FDA) and state agencies.

ByHeart has recalled and is offering a full refund for all products purchased on its website on or after August 1, 2025. Products sold nationwide in stores have also been recalled.

Customer information provided to FDA by Amazon shows that a limited quantity of recalled ByHeart infant formula was distributed globally to more than 20 countries: Argentina, Brazil, Brunei, Canada, Chile, China, Colombia, Ecuador, Egypt, Hong Kong, Israel, Jamaica, Japan, Republic of Korea, Peru, Philippines, Romania, Singapore, South Africa, Thailand, and the British Virgin Islands.

By the Numbers: The Current Outbreak Amid a Wider Infant Botulism Spike

As of November 26, the number of infant botulism cases linked to consumption of ByHeart formula includes 37 across 17 states. For 36 cases with illness onset information available, illnesses began between August 9 and November 19, 2025. Caregiver interviews identified that 37 infants were fed ByHeart Whole Nutrition powdered infant formula before getting sick. All 37 infants were hospitalized. No deaths have been reported. Illnesses have been reported in: Arizona, California, Idaho, Illinois, Kentucky, Massachusetts, Maine, Michigan, Minnesota, North Carolina, New Jersey, Oregon, Pennsylvania, Rhode Island, Texas, Washington, and Wisconsin.

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.

According to CDPH, this spike has grown from the originally reported 84 cases to now include 107 cases of infant botulism, occurring between August 1, 2025 and November 19, 2025. Not all infants treated for infant botulism during this spike have confirmed exposure to ByHeart infant formula.

Additionally, CDPH has reported another six cases of infant botulism with exposure to ByHeart infant formula that occurred between November 2024 and June 2025. Although these cases are under investigation by CDPH, at present, any cases that occurred before August 1, 2025 have not been definitively linked to the current outbreak. Parents of at least five babies said their infants were treated for botulism in late 2024 and early 2025, months ahead of the infant botulism spike noticed by CDPH.

FDA Releases Inspection Documents Confirming History of Food Safety Breaches at ByHeart Facilities

Since the outbreak came to light, ByHeart has come under increasing scrutiny for a history of food safety failures, including FDA inspections finding mold, dead insects, and leaking roof issues at its now-shuttered Reading, Pennsylvania facility. ByHeart was also issued a warning letter by FDA in 2023 for the presence of Cronobacter sakazakii in its product.

On November 26, FDA officially publicized its Establishment Inspection Reports (EIRs) and FDA Form 483s, Inspectional Observations (listed under Blendhouse LLC) from completed inspections conducted between 2022 and March 2025 at ByHeart facilities. ByHeart Inc. is the parent company of three Blendhouse manufacturing facilities in Allerton, Iowa; Portland, Oregon; and Reading, Pennsylvania.  

• Allerton, Iowa: The facility was last inspected in February 2025 and classified Voluntary Action Indicated (VAI), which cited Good Manufacturing Practice (GMP) deficiencies. A February 2025 Form 483 says the facility "approved and released for use an ingredient that was not manufactured, packaged, labeled, or held under conditions to prevent adulteration," citing rodent activity, rusty surfaces, and C. sakazakii-positive environmental swabs.
• Portland, Oregon: The facility was last inspected in March 2025 and classified No Action Indicated (NAI).   
• Reading, Pennsylvania: The facility was last inspected in January 2024 and classified Official Action Indicated (OAI). This facility has not been in operation since September 2023. A January 2024 Form 483 contains information about the facility's moldy water tank, leaking roof, and dead insect issues.

FDA’s investigation is ongoing to determine the point of contamination that resulted in the current outbreak.

Update, November 26, 2025: The article was edited to include the most recent information released by FDA.

Update, December 1, 2025: The article was edited to include the most recent information released by FDA.

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.