Federal health officials on Wednesday expanded an outbreak of infant botulism tied to recalled ByHeart baby formula to include all illnesses reported since the company began production in March 2022.

The U.S. Food and Drug Administration said investigators “cannot rule out the possibility that contamination might have affected all ByHeart formula products” ever made.

The outbreak now includes at least 51 infants in 19 states. The new case definition includes “any infant with botulism who was exposed to ByHeart formula at any time since the product’s release,” according to the U.S. Centers for Disease Control and Prevention. The most recent illness was reported on Dec. 1.

No deaths have been reported in the outbreak, which was announced Nov. 8.

Previously, health officials had said the outbreak included 39 suspected or confirmed cases of infant botulism reported in 18 states since August. That’s when officials at California’s Infant Botulism Treatment and Prevention Program reported a rise in treatment of infants who had consumed ByHeart formula. With the expanded definition, the CDC identified 10 additional cases that occurred from December 2023 through July 2025.

ByHeart, a New York-based manufacturer of organic infant formula founded in 2016, 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.

News that ByHeart products could have been contaminated for years was distressing to Andi Galindo, whose 5-week-old daughter, Rowan, was hospitalized in December 2023 with infant botulism after drinking the formula. Galindo, 36, of Redondo Beach, California, said she insisted on using ByHeart formula to supplement a low supply of breast milk because it was recommended by a lactation consultant as “very natural, very gentle, very good for the babies.”

“That’s a hard one,” Galindo said. “If there is proof that there were issues with their manufacturing and their plant all the way back from the beginning, that is a problem and they really need to be held accountable.”

Amy Mazziotti, 43, of Burbank, California, said her then-5-month-old son, Hank, fell ill and was treated for botulism in March, weeks after he began drinking ByHeart. Being included in the investigation of the outbreak “feels like a win for all of us,” she said Wednesday.