Nearly 40 babies have been sickened in an infant botulism outbreak tied to contaminated formula, federal health officials say.
The Food and Drug Administration on Wednesday reported 39 cases of confirmed or suspected illness in 18 states among babies who consumed ByHeart formula since August. The most recent illness occurred on Nov. 19.
No deaths have been reported in the outbreak, which was announced Nov. 8.
ByHeart, a New York-based manufacturer of
organic infant formula, recalled all its products sold in the U.S. on Nov. 11. The company, which accounts for about 1% of the U.S. infant formula market, had been selling about 200,000 cans of the product each month.
Some ByHeart products are still on shelves at stores including Walmart, Target, Kroger, Acme and Shaw's, despite the ongoing recall, the FDA reported.
It can take up to 30 days for symptoms of infant botulism to develop, medical experts said.
Here’s what to know about the outbreak and infant botulism.
The outbreak has sickened babies aged about 2 weeks to about 9 months, the FDA said. All the infants were hospitalized after consuming ByHeart powdered formula.
Earlier cases of infant botulism have been reported in babies who drank ByHeart formula and fell ill before Aug. 1. California health officials confirmed six such cases in that state between November 2024 and June 2025, although those are not considered part of the outbreak, health officials said.
California officials earlier confirmed that a sample from an open can of ByHeart baby formula fed to an infant who fell ill contained the type of bacteria that can lead to illness. And the company has said lab tests confirmed some samples were contaminated with that bacteria.
FDA inspectors have been to the company's infant formula production plants in Allerton, Iowa, and Portland, Oregon.
The FDA is investigating a rise in cases of infant botulism reported since August. “ByHeart brand formula is disproportionately represented among sick infants in this outbreak," the agency said.
Illnesses began between Aug. 9 and Nov. 19, federal officials said. Cases have been reported in Arizona, California, Idaho, Illinois, Kentucky, Maine, Massachusetts, Michigan, Minnesota, North Carolina, New Jersey, Oregon, Pennsylvania, Rhode Island, Texas, Virginia, Washington and Wisconsin.
Families of babies treated for botulism after drinking ByHeart formula have sued the company. Lawsuits filed in federal courts allege that the formula they fed their children was defective and ByHeart was negligent in selling it. They seek financial payment for medical bills, emotional distress and other harm.
Infant botulism typically affects fewer than 200 babies in the U.S. each year. As of Sept. 20, 133 cases had been reported in the U.S. according to the most recent Centers for Disease Control and Prevention records. There were 145 cases reported all of last year.
The infection is caused by a type of bacteria that produces a toxin in the large intestine. The bacterium is spread through hardy spores present in the environment that can cause serious illness, including paralysis.
Infants are particularly vulnerable to infection because their gut microbiomes are not developed enough to prevent the spores from germinating and producing the toxin. They can be sickened after exposure to the spores in dust, dirt or water or by eating contaminated honey.
Symptoms can take weeks to develop and can include poor feeding, loss of head control, drooping eyelids and a flat facial expression. Babies may feel “floppy” and can have problems swallowing or breathing.
Baby formula has previously been linked to sporadic cases of illness, but no known outbreaks of infant botulism tied to powdered formula have previously been confirmed, according to research studies.
The only treatment is known as BabyBIG, an IV medication made from the pooled blood plasma of adults immunized against botulism. California’s infant botulism program developed the product and is the sole source worldwide.
BabyBIG works to shorten hospital stays and decrease the severity of illness in babies with botulism. Because the infection can affect the ability to breathe, infants often need to be placed on ventilators.
There is little danger of infant formula shortages because ByHeart represents a small share of the market. That's far different from the crises in late 2021 and 2022, when four infants were sickened by a different germ after consuming formula made by Abbott Nutrition. Two of the babies died. No direct link was found between the Abbott products and the infections caused by a different germ, cronobacter sakazakii, but FDA officials closed the company's Michigan plant after contamination and other problems were detected.
Abbott recalled top brands of infant formula, triggering a nationwide shortage that lasted months.
In 2022, ByHeart recalled five batches of infant formula after a sample at the company's packaging plant tested positive for cronobacter sakazakii. In 2023, the FDA sent a warning letter to the company detailing “areas that still require corrective actions.” A ByHeart plant in Reading, Pennsylvania, was shut down in 2023 just before FDA inspectors found problems with mold, water leaks and insects, inspection documents show.
Federal health officials have vowed to overhaul the U.S. food supply and are taking a new look at infant formula.
Health Secretary Robert F. Kennedy Jr. has directed the FDA to review the nutrients and other ingredients in infant formula, which fills the bottles of millions of American babies.
The effort, dubbed “Operation Stork Speed,” is the first deep look at the ingredients since 1998.
FDA officials are reviewing comments from industry, health experts and public to decide next steps.
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