The Centers for Disease Control and Prevention has confirmed the first-ever infant botulism outbreak, tracing 51 hospitalized infants across 19 states to contaminated ByHeart Whole Nutrition infant formula. Laboratory testing detected Clostridium botulinum spores in the formula, prompting a full recall of all ByHeart products on November 11, 2025.
The outbreak, announced in a CDC update on December 10, 2025, marks a turning point in the understanding of a rare illness that typically surfaces as isolated cases. CDC investigators expanded the outbreak date range to include 10 cases dating back to December 2023, suggesting the contamination may have persisted undetected for nearly two years.
The First Infant Botulism Outbreak Ever Recorded
Infant botulism occurs when a baby swallows Clostridium botulinum spores that germinate in the gut and produce toxin. The illness is uncommon. CDC records show roughly 150 to 180 individual cases each year in the United States, almost always sporadic and unrelated. An outbreak — a cluster of cases from a common source — had never been documented.
Dr. Jennifer Cope, chief of the CDC’s Enteric Diseases Epidemiology Branch, called the cluster unprecedented. The agency typically expects scattered cases, not a surge linked to a single product. The fact that 51 infants required hospitalization and treatment with BabyBIG®, the standard antitoxin for infant botulism, underscores the severity of the exposure.
No deaths have been reported. All affected infants received treatment, and the outbreak investigation is now closed, though root-cause analysis continues.
From Surveillance Alert to Nationwide Recall
The breakthrough in this investigation came from California. On November 7, 2025, the California Department of Public Health’s Infant Botulism Treatment and Prevention Program (IBTPP) alerted the CDC to an unusual increase in infant botulism among babies consuming ByHeart formula. That same evening, CDC and FDA officials contacted ByHeart to push for market removal.
The response unfolded quickly. On November 8, the CDC warned parents to stop using two specific lots of ByHeart formula. By November 11, the agency expanded the warning to cover all ByHeart infant formula products, and ByHeart issued a full recall. CDC laboratories then confirmed the presence of botulism spores in formula samples collected from the homes of sick infants.
The investigation also retroactively identified 10 earlier cases from December 2023 that fit the outbreak pattern. This retrospective expansion illustrates how improved surveillance and data sharing can connect cases that initially appeared unrelated — a capability that public health experts consider essential for catching future threats sooner.
Spotting the Warning Signs in Infants
Infant botulism can be difficult to recognize because early symptoms mimic other common conditions. The illness often begins with constipation, which parents may not immediately flag as concerning. More distinctive signs include difficulty feeding — particularly weak sucking and swallowing — a weak or altered cry, and loss of head control.
If left untreated, the toxin can weaken the muscles used for breathing. Some infants require weeks of hospitalization and mechanical ventilation. The CDC emphasizes that all infants with suspected botulism should receive BabyBIG® promptly, without waiting for laboratory confirmation.
Symptoms can take several weeks to develop after exposure. Parents who used ByHeart formula should remain vigilant even if their infant appears healthy, the agency advises. The incubation period depends on how many spores the infant ingested and how quickly the bacteria colonize the gut.
Steps for Parents and Clinicians
The CDC’s guidance is direct: stop using any ByHeart Whole Nutrition infant formula immediately, even if containers are found for sale in stores or online. All lot numbers and all sizes — including cans and single-serve packets — are covered by the recall. Parents should wash any items or surfaces that touched the formula with hot, soapy water or a dishwasher.
For clinicians, the CDC recommends calling the IBTPP at 510-231-7600 for case consultation, available around the clock. If clinical consultation supports a diagnosis of infant botulism, treatment should begin immediately. Infant botulism is a notifiable disease, and all suspected cases must be reported to state public health departments.
The FDA has also posted guidance on its outbreak investigation page, and the CDC continues to update its botulism outbreak page with new findings. For broader coverage of public health threats and medical research, visit AXO News Health.
Evidence Caveats and Limitations
This article reports findings from a CDC investigation and does not constitute medical advice. The outbreak data reflects cases reported through December 2025 and may be revised as the root-cause investigation continues. The CDC notes that laboratory confirmation of C. botulinum in formula samples supports the link, but the exact mechanism of contamination during manufacturing remains under investigation.
Parents with concerns about their infant’s health should contact a healthcare provider immediately. The IBTPP consultation line is available 24 hours a day for clinicians seeking guidance on suspected cases.