The Centers for Disease Control and Prevention (CDC) has updated its investigation into an outbreak of infant botulism linked to ByHeart infant formula. The CDC, working with the California Department of Public Health’s Infant Botulism Treatment and Prevention Program (IBTPP), expanded the date range of the outbreak to include 10 cases dating back to December 2023.
As of December 10, 2025, there have been 51 infants from 19 states hospitalized and treated with BabyBIG as part of this outbreak. No deaths have been reported. Infant botulism occurs when babies ingest Clostridium botulinum spores that grow in their intestines and produce toxins. Early symptoms often include constipation, difficulty feeding, a weak or altered cry, and poor head control.
The CDC continues to advise parents not to use any ByHeart Whole Nutrition infant formula, even if it is still available in stores or online. Laboratory tests have confirmed contamination with botulism spores in the formula.
Dr. Jennifer Cope, chief of the Enteric Diseases Epidemiology Branch at CDC, said: “While we typically expect to see 150-180 individual cases of infant botulism annually, an outbreak of infant botulism is unprecedented.” She noted that on November 7, 2025, after being notified by IBTPP about a rise in cases among infants consuming ByHeart formula—a rare occurrence—CDC and the U.S. Food and Drug Administration contacted ByHeart to urge immediate action for product removal.
On November 8, CDC advised all parents nationwide to stop using two lots of ByHeart formula and alerted them about the outbreak. The warning was broadened on November 11 to cover all ByHeart infant formulas.
CDC laboratories are currently testing clinical samples from affected infants as well as samples from open containers collected from their homes.
According to the agency: “Although this is the first ever outbreak of infant botulism, CDC experts used their rapid response skillset to act immediately to save the lives of infants in America and provide clear guidance to frightened parents during a health emergency.”
The CDC highlights its ongoing role in protecting public health by quickly identifying disease threats and responding effectively across communities nationwide.
