An isolate of Clostridium botulinum recovered during confirmatory testing, supporting identification and characterization of botulinum neurotoxin–producing organisms.
Beginning in early November 2025, the U.S. Food and Drug Administration (FDA), in collaboration with the Centers for Disease Control and Prevention (CDC), initiated an investigation into a multistate outbreak of infant botulism associated with ByHeart Whole Nutrition powdered infant formula. Early epidemiologic findings demonstrated a strong association between illness and consumption of the product, prompting a voluntary recall. By mid-November, laboratory testing conducted by multiple laboratories nationwide identified Clostridium botulinum Type A toxin-producing organisms in opened containers of the formula that had been consumed by affected infants.
The New York State Department of Health’s Wadsworth Center Biodefense Laboratory maintains a highly specialized Clostridium botulinum testing capability that supports public health surveillance, outbreak response, food defense, and laboratory preparedness at both the state and national levels. Utilizing high-containment laboratory infrastructure, highly trained personnel, and validated molecular and culture-based methodologies, the laboratory conducts sensitive detection and characterization of C. botulinum in clinical, environmental, food, and product matrices. Core capabilities include real-time PCR for detection of toxin-producing organisms, active toxin detection using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and pathogen characterization through whole-genome sequencing. Based on this specialized expertise, the FDA requested assistance from the Wadsworth Center Biodefense Laboratory to test unopened containers of powdered infant formula as part of the national investigation.
Through extensive testing, the Wadsworth Center Biodefense Laboratory became the first laboratory to detect and isolate Clostridium botulinum Type A from an unopened container of powdered infant formula. The isolate was sequenced and genetically compared with patient isolates and other circulating strains. Using batch and lot information associated with the product, the FDA was subsequently able to trace potential sources of contamination to specific dry milk powder lots. The Biodefense Laboratory was again requested to perform confirmatory testing on the suspected dry milk powder and successfully detected, isolated, and sequenced C. botulinum Type A. Genetic analysis demonstrated that the strain identified in the dry milk powder matched the strain detected in the finished ByHeart powdered infant formula.
Overall, the investigation identified 51 suspected or confirmed cases of infant botulism across 19 states, with illness onset dates ranging from December 2023 through December 2025. This investigation underscores the critical role of the advanced public health laboratory capacity at the Wadsworth Center in identifying sources of contamination, guiding regulatory action, and protecting vulnerable populations.