Handout image of recalled ByHeart Whole Nutrition Infant Formula.

An outbreak of infant botulism linked to recalled ByHeart baby formula has broadened as federal health officials say the company's products may have been contaminated since they were released in March 2022.

As of Dec. 10, the total outbreak now includes at least 51 infants with suspected or confirmed botulism across 19 states that were exposed to ByHeart Whole Nutrition infant formula, according to the U.S. Food and Drug Administration. Health officials previously reported that the outbreak included 39 suspected or confirmed cases in 18 states since August of this year.

But as the FDA, along with the Centers for Disease Control and Prevention and other state and local health agencies, continued their investigation into the outbreak, the CDC said it has expanded its case definition to include "any infant with botulism who was exposed to ByHeart formula at any time since the product’s release."

Epidemiologic and laboratory data showed that ByHeart baby formula may have been tainted with Clostridium botulinum, a bacterium that produces a neurotoxin that causes botulism, according to the FDA.

"ByHeart’s and FDA’s investigations into the root cause of the outbreak are ongoing, and at this time, FDA cannot rule out the possibility that contamination might have affected all ByHeart formula products," the agency said.

With the broadened definition, the CDC said it has identified 10 additional cases that occurred from December 2023 to July 2025. The FDA noted that no cases have been identified from March 2022 through December 2023.

ByHeart, a next-generation baby nutrition company based in New York, announced a voluntary recall of some batches of its powdered infant formula on Nov. 8 after health officials tied the product to an infant botulism outbreak. Days later, the company expanded its recall to include all batches of ByHeart Whole Nutrition Infant Formula cans and "Anywhere Pack" sticks nationwide.

At least 51 cases tied to ByHeart baby formula

The baby formula was distributed online and in stores nationwide and internationally, according to the FDA.

At least 51 infants who became ill were hospitalized, but no deaths have been reported as of Dec. 10, the agency said. The infants ranged in age from 16 to 264 days.

The FDA said laboratory confirmation for some cases remains ongoing and that the most recent illness was reported on Dec. 1. States with suspected or confirmed cases include Arizona, California, Idaho, Illinois, Kentucky, Massachusetts, Maine, Michigan, Minnesota, North Carolina, New Jersey, Ohio, Oregon, Pennsylvania, Rhode Island, Texas, Virginia, Washington, and Wisconsin.

"State and local public health officials are interviewing caregivers about the foods the infants were fed in the month before they got sick," the FDA said. "Fifty-one infants have been identified that were fed ByHeart Whole Nutrition powdered infant formula before getting sick."

Since Nov. 26, the FDA said it has not received reports of recalled baby formula being found in stores. In a statement on Nov. 24, ByHeart said testing by an independent laboratory showed that five of 36 samples from three different lots contained Clostridium botulinum.

"Based on these results, we cannot rule out the risk that all ByHeart formula across all product lots may have been contaminated," the company said in the statement.

ByHeart sued over recalled formula

Families of babies sickened with botulism have sued ByHeart. USA TODAY reported in November that two families in Arizona and Kentucky filed complaints in federal courts against ByHeart after their babies contracted the rare and potentially deadly disease.

Both families alleged that ByHeart is directly responsible for their infant children being sickened with botulism.

Infant botulism is a "rare but serious illness" that affects babies under 1 year old, according to the Cleveland Clinic, a nonprofit academic medical center.

Parents and guardians who see symptoms in an infant should seek immediate medical care, according to the CDC. Symptoms include poor feeding, loss of head control, difficulty swallowing, and decreased facial expression.

Health officials have advised parents and guardians who have recently fed their infant the recalled formula to remain vigilant, as botulism symptoms can take multiple weeks to develop.

Contributing: Jonathan Limehouse and Caroline C. Boyle, USA TODAY

This article originally appeared on USA TODAY: Botulism outbreak grows as tainted ByHeart products may date to 2022

Reporting by Thao Nguyen, USA TODAY / USA TODAY

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