Infant Formula and Public Health

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.