When People Got Sick: Infant Botulism Outbreak, November 2025

Key points

  • No new cases have been added to the investigation since the December 10, 2025 update.
  • Infant botulism happens when a baby swallows Clostridium botulinum spores that grow in the gut and make toxin.
  • Infant botulism often starts with constipation but is usually first noticed as difficulty feeding (sucking and swallowing), a weak and altered cry, and lack of head control.
Can of ByHeart infant formula

When people got sick

This chart shows when 51 infants in this infant botulism outbreak got sick.