What We Know About the ByHeart Infant Formula Botulism Outbreak
This is the first-ever outbreak of infant botulism linked to powdered infant formula in the United States. As of February 26, 2026, when CDC declared the outbreak over, 48 infants across 17 states (28 confirmed and 20 probable cases) were included in CDC’s final count after consuming ByHeart Whole Nutrition Infant Formula contaminated with Clostridium botulinum Type A spores.
All 48 infants required hospitalization and treatment with BabyBIG (Botulism Immune Globulin Intravenous), a specialized antitoxin. No deaths have been reported. The affected infants ranged from 16 to 264 days old.
How the Outbreak Was Discovered
The California Department of Public Health (CDPH) Infant Botulism Treatment and Prevention Program (IBTPP) first identified a surge in infant botulism cases and notified the CDC on November 7, 2025. Within 24 hours, the CDC and FDA contacted ByHeart. On November 8, CDPH preliminarily detected botulinum toxin Type A in an open can of ByHeart formula fed to a diagnosed infant.
CDC typically sees 150 to 180 individual cases of infant botulism a year, and it called an outbreak of infant botulism like this one unprecedented.
The Contamination Source
FDA and ByHeart testing found Clostridium botulinum in finished formula, a base mix sample, and organic whole milk powder. Whole genome sequencing matched two milk powder samples to a sick infant and to a positive formula sample, but testing found 17 different strains and FDA says it hasn’t determined the root cause. FDA’s inspections of ByHeart’s plants, which ended when the outbreak was declared over in February 2026, found the bacteria in a powdered milk ingredient but nothing else inside the plants that explains the outbreak, so its root cause work now focuses on ingredients. FDA collected some of the matching milk powder samples at Dairy Farmers of America, which it identifies as the processor for ByHeart’s supplier, Organic West Milk.
ByHeart reported that 6 of 36 finished product samples tested positive for C. botulinum Type A, all from batches 251261P2 and 251131P2. An unopened can from batch 251481P2, collected in Arizona and tested through FDA’s lab network, also tested positive.
Link to the 2026 Nara Organics Outbreak
In June 2026, CDC and FDA announced a second outbreak, in which four infants in California, Pennsylvania, and Washington got infant botulism after being fed Nara Organics Whole Milk Organic Infant Formula. On August 27, 2026, CDC and FDA said the data indicate a common source of contamination for the two outbreaks. FDA pointed to two findings. Genetic sequencing matched a sample from one Nara infant to a sample from a ByHeart infant, a ByHeart formula base sample, and four unopened ByHeart cans. And Nara’s formula used milk from Organic West Milk that Dairy Farmers of America spray dried, the same suppliers behind ByHeart’s milk powder. FDA later learned that the customer list Organic West Milk gave it in the 2025 investigation was incomplete and left out Nara’s manufacturers. FDA says there isn’t enough evidence yet to tell whether the milk was contaminated before or during drying, and its root cause investigation is ongoing. Read about the Nara Organics outbreak.
The Recall
- November 8, 2025: ByHeart voluntarily recalled two specific batches (251261P2 and 251131P2)
- November 11, 2025: Recall expanded to ALL ByHeart formula products, all lot numbers, all formats
Despite the recall, the FDA found recalled formula still on store shelves at more than 175 locations across 36 states. On December 12, 2025, the FDA sent warning letters to Target, Walmart, Kroger, and Albertsons for failing to remove recalled products. Target had even offered a $2.00 promotional discount on recalled formula from November 16-22.
ByHeart’s History of Safety Failures
This isn’t ByHeart’s first contamination issue:
- December 2022: Recalled 5 batches after a sample tested positive for Cronobacter sakazakii. ByHeart’s root cause analysis incorrectly blamed “a laboratory error.”
- August 2023: FDA sent ByHeart a warning letter over failures to control and monitor for Cronobacter at its Reading, Pennsylvania plant. The plant hasn’t operated since September 2023.
- January 2024: FDA inspected the Reading plant and classified the inspection Official Action Indicated for manufacturing practice deficiencies.
Your Legal Rights
If your infant consumed ByHeart formula and was diagnosed with or showed symptoms of infant botulism, your family may be entitled to compensation. Infant botulism treatment requires specialized care, and hospitalization typically lasts weeks.
Ron Simon & Associates is a food poisoning law firm that has recovered over $850 million for victims nationwide. Our attorneys have an exclusive focus on foodborne illness litigation and are actively investigating this outbreak. You pay us nothing unless we win your case.