FDA expands ByHeart infant botulism outbreak
The FDA has expanded its investigation of a botulism outbreak linked to ByHeart infant formula to include all ByHeart products, reporting 51 infants sickened across 19 states — with California accounting for at least nine cases and Texas seven or eight. After broadening the case definition, investigators added 12 cases (two within the original timeline and 10 from Dec. 2023–July 2025), with the most recent illness reported Dec. 1, 2025; the FDA says it "cannot rule out" contamination of any ByHeart formula produced since March 2022, and ByHeart, which had about 1% of the U.S. formula market (~200,000 cans/month), says it is cooperating.
📌 Key Facts
- The outbreak is of infant botulism tied to ByHeart formula products and now includes 51 babies across 19 states; California has at least nine cases and Texas has seven or eight.
- The FDA and CDC expanded the case definition, identifying 12 additional cases (two within the original timeline and 10 occurring from December 2023 through July 2025), which contributed to the updated total.
- The most recent reported illness in the outbreak occurred on December 1, 2025.
- The FDA says it "cannot rule out" contamination across all ByHeart formula produced since March 2022; ByHeart states it is cooperating with authorities to determine the root cause.
- Before the recall, ByHeart’s market footprint was roughly 1% of the U.S. infant formula market, with about 200,000 cans sold per month.
📊 Relevant Data
Soil samples from the state of California were found to harbour C. botulinum spores at the highest rate in the United States.
Viable Clostridium botulinum spores not detected in the household dust of UK infant botulism cases — PMC
In 2021, California reported 45 cases of infant botulism, accounting for 25% of the national total.
Hispanics and Asian families have a higher incidence of infant botulism because of their use of herbal medications and raw honey.
Diagnosing and Treating Infant Botulism — BST Quarterly
📰 Sources (2)
- FDA/CDC list the 19 affected states and note California has at least nine cases and Texas has seven or eight.
- Breakout of added cases: 12 additional cases identified via the expanded definition (two within the original timeline and 10 from Dec. 2023 through July 2025).
- Confirms the most recent reported illness occurred on Dec. 1, 2025.
- ByHeart’s market footprint before the recall: roughly 1% of U.S. formula market and about 200,000 cans sold per month.
- Reiterates FDA’s position that it "cannot rule out" contamination across all ByHeart formula produced since March 2022 and includes ByHeart’s statement that it is cooperating to determine root cause.