As of December 3, 2025, a total of 39 infants with suspected or confirmed infant botulism and confirmed exposure to ByHeart Whole Nutrition infant formula (various lots) have been reported across 18 states. All 39 infants were hospitalized; no deaths have been reported.

Onset of illness ranges between August 9 and November 19, 2025. Laboratory confirmation for some cases is ongoing. States in which cases have been reported include Arizona, California, Idaho, Illinois, Kentucky, Massachusetts, Maine, Michigan, Minnesota, North Carolina, New Jersey, Oregon, Pennsylvania, Rhode Island, Texas, Virginia, Washington, and Wisconsin.

On November 19, ByHeart reported that it tested 36 samples of infant formula across three lots, five of which tested positive for Clostridium botulinum Type A. The specific lots that were tested have not been publicly revealed by ByHeart.

Previously, the California Department of Public Health (CDPH) reported that a can of ByHeart infant formula (lot 206VABP/251131P2), which was fed to an infant with botulism and was taken from the home of a consumer, tested positive for the outbreak strain of Clostridium botulinum. Additional testing by ByHeart, the U.S. Food and Drug Administration, the U.S. Centers for Disease Control and Prevention (CDC), and state public health partners is underway.

The 39 outbreak cases are part of a broader spike in infant botulism cases, first noticed by CDPH’s Infant Botulism Treatment and Prevention Program (IBTPP), which operates the only global source of infant botulism treatment worldwide. This spike has grown from the originally reported 84 cases to now include 107 cases of infant botulism. Not all infants treated for infant botulism during this spike have confirmed exposure to ByHeart infant formula.

Since the outbreak came to light, ByHeart has come under increasing scrutiny for a history of food safety failures. FDA inspections found mold, dead insects, and leaking roof issues at its Reading, Pennsylvania facility (now closed), as well as rodent activity, rusty surfaces, and Cronobacter sakazakii-positive environmental swabs at the company’s Fullerton, Iowa plant.

All ByHeart formula products and lots, which were sold online and in stores, have been recalled nationwide. FDA warns that recalled formula is still being found on store shelves at Walmart, Target, Kroger, Acme, and Shaw’s, despite the recall.

ByHeart products have also been distributed to Guam, Puerto Rico, and internationally to Argentina, Brazil, Brunei, Canada, Chile, China, Colombia, Ecuador, Egypt, Hong Kong, Israel, Jamaica, Japan, Republic of Korea, Peru, Philippines, Romania, Singapore, South Africa, Thailand, and the British Virgin Islands.