Marler Clark urges Public Health to reopen all 2025 Infant Botulism Investigations

Since this outbreak broke early last Saturday, I have learned far too much about Infant Botulism. I have now spoken with a half dozen experts and nearly a dozen parents of victims whose illnesses span from February 2025 to a few days ago. Interestingly, several of the early 2025 cases identified ByHeart formula as a product their child consumed before becoming sick. I know, correlation is not causation. However, taking a hard look at all the 2025 Infant Botulism with fresh eyes might well identify common denominators that may solve a larger problem and prevent the next one.

CDC, public health and regulatory officials in several states, the Infant Botulism Treatment and Prevention Program (IBTPP), and the U.S. Food and Drug Administration (FDA) have confirmed that with epidemiologic and laboratory data ByHeart Whole Nutrition infant formula might be contaminated with Clostridium botulinum and has made infants sick.

Since the last update on November 8, 2025, two new cases from two new states have been added to this investigation: Kentucky and North Carolina. Both cases were hospitalized and treated with BabyBIG®.

As of November 10, 2025, this outbreak includes 15 infants with suspected or confirmed infant botulism from 12 states, Arizona 1, California 2, Illinois 2, Kentucky 1, Minnesota 1, North Carolina 1, New Jersey 1, Oregon 1, Pennsylvania 1, Rhode Island 1, Texas 2 and Washington 1.

Laboratory confirmation for some cases is ongoing. For 14 cases with illness onset information available, illnesses started on dates ranging from August 9 to November 10, 2025 (see timeline). All 15 infants were hospitalized and treated with BabyBIG®. No deaths have been reported. For 14 infants with age and sex information available, they range in age from 16 to 157 days and 7 (50%) are female.

According to information shared by IBTPP, since August 1, 2025, through November 10, 2025, 84 infants nationwide have received BabyBIG® treatment. Among them, 36 (43%) had any powdered infant formula exposure. Notably, more than 40% (15) consumed ByHeart Whole Nutrition infant formula. This information shows that ByHeart brand formula is disproportionately represented among sick infants in this outbreak, especially given FDA’s data that ByHeart represents an estimated 1% of all infant formula sales in the United States. Investigations remain ongoing but have not identified any other infant formula brands or shared exposures that pose a risk to infants at this time.

Officials in several states have collected leftover infant formula for testing. Preliminary laboratory results reported by the California Department of Public Health suggest the presence of the bacteria that produce botulinum toxin in an open can of ByHeart infant formula (lot 206VABP/251131P2) that was fed to an infant with infant botulism. Additional product testing by states, CDC, and FDA is ongoing with results expected in the coming weeks.

CDC and FDA are concerned that other lots of ByHeart Whole Nutrition infant may be contaminated and are making infants sick with infant botulism. Parents and caregivers have reported feeding infants in this outbreak different lots of ByHeart infant formula that were not included in the company’s initial recall on November 8, 2025. Parents and caregivers are urged to stop using any ByHeart Whole Nutrition infant formula immediately.

Republished with permission from Bill Marler and Marler Clark. Copyright (c) Marler Clark LLP, PS. All rights reserved.