Botulism, a known risk in infant formula?

One thing about preparing for a lawsuit is digging deep into the facts and the science. One of the recent refrains in this ByHeart infant formula Botulism Outbreak, is how could we have know? Well, you likely could have. Here are some abstracts of discussion of that risk.

Infant botulism is now the most common form of human botulism in Canada and the United States. Infant botulism is a severe neuroparalytic disease caused by ingestion of the spore-forming neurotoxic clostridia, including Clostridium botulinum that colonize the large intestine and subsequently produce botulinum neurotoxin in situ. It has been over a century since the first surveys documenting the ubiquitous prevalence of C. botulinum in soils around the world. Since then, honey has been identified as the only well-known risk factor for infant botulism despite a multitude of international environmental surveys isolating C. botulinum spores from ground soil, aquatic sediments, and commonly available infant foods. Associations of infant botulism cases with confirmed sources of C. botulinum exposure have primarily implicated outdoor soil and indoor dust, as well as commonly ingested foods including honey, dry cereals, and even powdered infant formula. Yet the origin of infection remains unknown for most infant botulism cases. This review summarizes the various surveys from around the world for C. botulinum in environmental soils and sediments, honey, and other infant foods, as well as laboratory-confirmed associations with documented infant botulism cases. Additional factors are also discussed, including the composition of infant gut microbiota and the practice of breastfeeding. We make several recommendations to better identify sources of exposure to C. botulinum spores that could lead to effective preventive measures and help reduce the incidence of this rare but life-threatening disease. https://www.marlerblog.com/files/2025/11/Brett-et-al.-2005.pdf

Infant botulism was confirmed in a 5-month-old female by both isolation of Clostridium botulinum type B and by detection of type B botulinum neurotoxin in rectal washout and faeces. DNA fingerprinting of nine isolates from faeces yielded two different amplified-fragment length polymorphism (AFLP) patterns. C. botulinum was isolated from two of 14 food and drink items from the patient’s home: C. botulinum type A was recovered from an opened container of dried rice pudding and C. botulinum type B from opened infant formula milk powder. Ten C. botulinum type B isolates from the opened infant formula yielded four AFLP patterns, two of which were indistinguishable from the clinical isolates. Fifteen unopened foods were tested and C. botulinum type B of a unique AFLP pattern was recovered from one unopened infant formula of the same batch as the opened container. It is suggested that multiple C. botulinum were present in both food and the intestine during infant botulism. https://www.marlerblog.com/files/2025/11/Harris-et-al.-2025.pdf

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