Why This Matters:
- Infant botulism (IB) is a rare but potentially life-threatening neuroparalytic illness in infants caused by intestinal colonisation with Clostridium botulinum.
- On November 8, 2025, the FDA issued a recall for an infant formula due to possible contamination with C. botulinum.
- As of November 19, 2025, a total of 31 infants from 15 states with suspected or confirmed infant botulism and confirmed exposure to ByHeart Whole Nutrition infant formula (various lots) were reported by CDC and FDA.2,3
- Testing by the California Department of Public Health (CDPH) revealed the presence of the organism in an opened can of infant formula collected from one of the patients.
- According to ByHeart, later "third-party laboratory analysis of unopened infant formula products retained at its facility identified Clostridium botulinum."
- "ByHeart states that it will continue to investigate these findings and perform ongoing testing to identify the source of contamination."
- Infant botulism cases appear to be on the rise for unknown reasons.
- As this is the first outrbeak involving Clostridium botulinum in infant formula, regulations to date do not require routine testing of infant formula for this organism.
Key Findings: Dabritz and members of the California Department of Public Health (2025) present a worldwide epidemiological summary of Infant Botulism (IB) cases from 2007 through 2021 based on active and passive surveillance through the Infant Botulism Treatment and Prevention Program, epidemiologist contacts across countries, and published literature.1 A total of 2,943 laboratory-confirmed IB cases in 18 countries were indentified.
- Of the 2,943 global cases, 1,587 (≈54%) were type A toxin, and 1,254 (≈43%) were type B; other toxin types (e.g., E, F) were rare.
- The median age at onset was 16.8 weeks (3.9 months), and approximately 48% of cases were female.
- Aside from honey, IB cases worldwide were linked to consumption of powdered infant formula contaminated with clostridial spores (2 possible cases), to infant rice cereal, to well water, and to unprocessed chamomile tea (with honey).
- There was a significant increasing linear trend for cases worldwide (P = 0.97).
- In the US:
- US cases are on the rise: An average of 130 cases occurred annually, with a significant upward linear trend in the annual incidence (P = 0.95) where the average for 2017 to 2021 was 159 cases per year.
- The incidence of IB was 3.3 cases per 100 000 live births with considerable variability among US regions.
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The incidence of IB per 100 000 live births was highest in the Northeast (4.9) and West (6.0) regions.
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Sporetype Type A IB occurs mostly in Western states and Type B IB mostly in the east and south.
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The incidence from 2007 to 2021 was higher than the US rate (3.3) in Delaware (20.4), Pennsylvania (12.1), Maryland (6.7), and New Jersey (7.5).
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- Honey exposure, a known risk, was much less common in U.S. IB cases (3.8%) than in ROW cases (19.7%).
The authors suggest that the geographic distribution of reported IB cases does not match environmental presence of Clostridium botulinum spores, suggesting other sources of potential transmission.
Bigger Picture:
- Underrecognized global burden: The discrepancy between environmental spore distribution and reported cases suggests many regions may under-diagnose or under-report infant botulism.
- Prevention strategy implications: With honey playing a much smaller role in U.S. IB, prevention messaging may need to emphasize broader environmental risk factors, not just honey.
- Need for global capacity building: Strengthening IB surveillance, diagnosis (e.g., toxin testing), and prevention in low- and middle-income countries could uncover hidden disease burden.
- Clinical awareness: Pediatricians should remain vigilant for botulism in infants, especially when presenting with cranial nerve palsies, hypotonia, constipation, or poor feeding — even in regions with few reported cases.
(Image Credit: iStock/Dr_Microbe)
References:
- Dabritz et al. (2025) Global Occurrence of Infant Botulism: 2007-2021. Pediatrics. Vol. 155, Issue 4: e2024068791.
- FDA, 2025. Outbreak Investigation of Infant Botulism: Infant Formula (November 2025) accessed on 11.20.2025.
- CDC, 2025. Infant Botulism Outbreak Linked to Infant Formula, November 2025. Accessed on 11.20.2025.
