State of California—Health and Human Services Agency
California Department of Public Health

Health Advisory

TO: Healthcare Providers

Outbreak of Infant Botulism Linked to ByHeart Infant Formula

11/11/2025

Key Messages

The California Department of Public Health (CDPH), the Centers for Disease Control and Prevention (CDC) and other state health departments are investigating an unprecedented multi-state outbreak of infant botulism linked to infant formula.
Fifteen infants with suspected or confirmed infant botulism have been identified including two in California and 13 in eleven other states: Arizona, Illinois (2), Minnesota, New Jersey, Oregon, Pennsylvania, Rhode Island, Texas (2), Washington, Kentucky, and Illinois. As of November 11, 2025, 10 cases have been confirmed and 5 have testing underway.
Illness onset dates range from mid-August to the present. All infants were hospitalized and received BabyBIG^®. No deaths have been reported. Infants ranged in age from 2 weeks to 5 months olds. All 15 were fed ByHeart Whole Nutrition infant formula.
Preliminary testing of ByHeart Whole Nutrition infant formula at the California Department of Public Health Center for Laboratory Sciences Microbial Diseases Laboratory (CDPH CLS MDL) laboratory indicates the presence of C. botulinum type A spores in the sample of the powdered infant formula. Additional testing is in progress.
On November 11, 2025, ByHeart, Inc. has expanded the voluntary recall to all ByHeart formula nationwide - this includes both cans and single-serve Anywhere Pack™ sticks. FDA is working to ensure all potentially impacted products are removed from the market. CDPH is working on obtaining distribution information and will share with local health departments as soon as it becomes available to inform follow up with retailers. FDA's investigation is ongoing to determine the point of contamination and if any additional products are impacted.
Parents should discontinue use of ByHeart formula immediately.
ByHeart Whole Nutrition Infant Formula is available online and at major retailers nationwide. FDA reports that ByHeart Whole Nutrition Infant Formula makes up ~1% of all infant formula sales in the United States. This recall will not create shortage concerns of infant formula for parents and caregivers.
Clinicians and public health professionals should call the CDPH Infant Botulism Treatment and Prevention Program (IBTPP) directly for consultation for suspected infant botulism cases at 510-231-7600 (available 24/7).
Health care providers should report suspected cases of infant botulism to their local health department immediately, to facilitate investigation, testing and timely treatment with BabyBIG if indicated.

Background

Infant botulism is caused by colonization with Clostridium botulinum spores, which germinate and produce botulinum neurotoxin in the intenstine. The immature gut microbiota and reduced bile acid levels in infants create a permissive environment for spore germination and toxin production. Infant botulism occurs when swallowed spores for Clostridium botulinum or related species temporarily colonize a baby's large intestine and produce toxin. The toxin is then absorbed and carried in the baby’s bloodstream to the neuromuscular junction where it cleaves key intracellular proteins needed for the release of the neurotransmitter acetylcholine. Constipation is often the earliest sign followed by poor feeding (weak suck, difficulty swallowing), hypotonia (floppy baby syndrome), weak or altered cry, loss of head control, facial weakness (e.g., diminished facial expression), ptosis, progressive, symmetric, descending flaccid paralysis and respiratory compromise in severe cases. Infant botulism primarily affects infants under six months of age. Botulism, including infant botulism, is a nationally notifiable disease in the U.S. Infant botulism is usually sporadic, and for most cases, a source is not identified. This outbreak is the first of its kind in terms of the number of infants affected and the link to infant formula.

Diagnosis is based on clinical history and physical exam along with test for botulinum neurotoxin in stool. Confirmatory testing includes detection of botulinum toxin in stool or isolation of C. botulinum or toxigenic C. baratii or C. butyricum from stool. This testing can be done at the CDPH laboratory.

Treatment should not be delayed while awaiting laboratory confirmation. BabyBIG® (Human Botulism Immune Globulin Intravenous) is the treatment of choice and should be administered as soon as infant botulism is suspected. BabyBIG® is only available through the CDPH IBTPP program. Meticulous supportive care, including respiratory and nutritional support, is often required. Hospitalization is typically prolonged (weeks), but prognosis is excellent with timely treatment.

Providers caring for a patient with suspected infant botulism should notify their local health department and immediately reach out to the Infant Botulism Treatment and Prevention Program (IBTPP) for medical consultation: Call 510-231-7600 (available 24/7).

Recommendations

Maintain a high index suspicion for infant botulism and ask parents about the use of ByHeart Whole Nutrition infant formula in any suspected cases

Parents of children with suspected infant botulism are encouraged to retain opened containers and save lot numbers and expiration dates of any infant formula consumed by the child and report to their local health department.

If infant botulism is suspected, consult with experts at the CDPH Infant Botulism Treatment and Prevention Program immediately at 510-231-7600. Consultation is available 24/7.
If clinical consultation supports a diagnosis of infant botulism, begin treatment with BabyBIG® as soon as possible. Do not wait for laboratory confirmation.
Infant botulism is a notifiable disease. All suspected cases must be reported immediately by telephone to the local health department of the patient’s residence.