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
Of the different forms of botulism, infant botulism is the most common form reported in the USA (Shapiro et al., 1998) and the European Union (ECDC, 2011). Infant botulism is caused when neurotoxigenic Clostridium spores are ingested, germinate and colonise the immature gut of the infant and produce neurotoxin. Infants less than one year old are at risk of infant botulism and those less than 6 months old are particularly vulnerable, which likely reflects the inability of the infant’s immature intestinal microbiota to resist colonization by C. botulinum. The clinical presentation and management of the disease is discussed by Radsel et al (2013). The identification of foodstuffs associated with cases of infant botulism is difficult due to the generally long incubation time before manifestation of the disease, but the main documentedevidence exists for honey as a vehicle (Midura, 1996) and spores of C. botulinum have been isolated from honey (Hauschild et al., 1988; Al-Waili et al., 2012). In the UK, a case of infant botulism was presumptively linked to infant formula (Brett et al., 2005) and C. botulinum type B spores were reported in both an opened and unopened can. However, the AFLP (Amplified Fragment Length Polymorphism) type of the isolate from the unopened can was different to that of the isolate from the infant. In addition, differences in the PCR profile of C. botulinum isolated from the unopened can and the isolate from the infant suffering from infant botulism led Johnson et al. (2005) to conclude that the infant formula powder was not the source of transmission of spores to the infant. With respect to hazardous microorganisms associated with infant formula, FAO/WHO categorized C. botulinum as “causality less plausible or not yet demonstrated” because, although having been identified in powdered infant formula, they had not been implicated as causing illness in infants (FAO/WHO, 2004). Consequently, C. botulinum is not considered a hazard in the Codex international hygiene standard for infant formula (CAC, 2008). In a recent report on infant botulism by the UK Food Standards Agency (ACMSF, 2006), experts carrying out a risk assessment on infant botulism agreed that, based on available data on the presence of spores of C. botulinum in infant food (i.e., broader than just powdered infant formula) the most likely mean value was 0.3 spores per kg, the minimum mean was 0.001 spores per kg, and the maximum mean value was 10 spores per kg. The experts considered that levels of 10 spores per pack of 121 g (hence approximately <1 spore per serving of 13g of powdered infant formula) would represent only a low risk of disease. https://www.marlerblog.com/files/2025/11/ICMSF_Infant_Formula_Testing_Revision1-20140117.pdf