Clostridium botulinum (toxin type A) United States · 2025 to 2026

Infant botulism outbreak linked to ByHeart infant formula, United States, 2025

FDA reported 48 infant botulism illnesses, 28 confirmed and 20 probable, in 17 states, all hospitalised and with no deaths. ByHeart recalled two lots on 8 November 2025 and expanded the recall to all products on 11 November. FDA samples tested positive for Clostridium botulinum type A and matched isolates from organic whole milk powder. FDA said its inspections found Clostridium botulinum in a powdered milk ingredient. CDC declared the outbreak over and FDA said its root cause work on ingredients was ongoing.¹

Counts as reported on 3 June 2026.¹ Food vehicle: ByHeart Whole Nutrition Infant Formula. Company named in official findings: ByHeart.

Timeline

1. 8 November 2025California Department of Public Health preliminarily detected botulinum neurotoxin type A in an opened can. ByHeart agreed to recall two lots.¹
2. 11 November 2025ByHeart expanded the recall to all ByHeart formula.¹
3. 29 November 2025Last reported illness onset.¹
4. 23 January 2026FDA samples tested positive for Clostridium botulinum type A and matched organic whole milk powder isolates.¹
5. 26 February 2026Whole genome sequencing linked a base mix sample and ingredient isolates to the outbreak cluster. CDC declared the outbreak over.¹
6. 3 June 2026FDA reported inspection findings and said the root cause investigation was ongoing.¹

Sources

1. US Food and Drug Administration, Outbreak Investigation of Infant Botulism: Infant Formula (November 2025) (3 June 2026)