Between November 2025 and February 2026, the FDA and CDC investigated a multistate outbreak of infant botulism linked to ByHeart Whole Nutrition infant formula, which resulted in 48 hospitalizations across 17 states. The outbreak, which has now ended, involved 28 confirmed cases and 20 probable cases of infant botulism. While no deaths occurred, the incident highlights the critical importance of formula safety and what parents should watch for if their child consumed the recalled product. What Happened With ByHeart Formula? In November 2025, health officials discovered that ByHeart Whole Nutrition infant formula was contaminated with Clostridium botulinum, a bacterium that produces a dangerous toxin. The FDA and CDC, working with the California Department of Public Health and other state partners, traced the outbreak to this specific brand. All ByHeart infant formula productsâincluding cans and single-serve "anywhere pack" sticksâwere recalled nationwide. ByHeart formula represented approximately 1% of all infant formula sold in the United States, so the recall did not create widespread formula shortages for other families. The products were available for purchase online and in stores at major retailers nationwide before the recall was issued. How Many Infants Were Affected? As of February 26, 2026, the outbreak investigation included 48 total hospitalizations across 17 states: Arizona, California, Idaho, Illinois, Kentucky, Massachusetts, Michigan, Minnesota, North Carolina, New Jersey, Oregon, Pennsylvania, Rhode Island, Texas, Virginia, Washington, and Wisconsin. The cases also extended to Guam and Puerto Rico, as well as international locations. The outbreak timeline is important: the last illness onset was November 29, 2025, and no new cases were added after December 10, 2025. On February 26, 2026, the CDC officially declared the outbreak over. However, investigators did exclude 3 previously reported cases from 3 states after determining those infants had been diagnosed with other illnesses. What Are the Symptoms of Infant Botulism? Infant botulism is a serious condition that develops when infants ingest spores of Clostridium botulinum. The bacteria produce a toxin that affects the nervous system. One critical aspect of this illness is that symptoms can take as long as several weeks to develop after a baby consumes contaminated formula, which is why ongoing monitoring is essential. Early warning signs include constipation, poor feeding, loss of head control, and difficulty swallowing. If left untreated, the condition can progress to difficulty breathing and respiratory arrest, which is why immediate medical attention is crucial if you notice these symptoms. Steps to Take if Your Child Consumed ByHeart Formula - Stop Using the Product Immediately: If you have any ByHeart infant formula in your home, discontinue use right away and do not feed it to your child, even if it appears normal. - Monitor for Symptoms: Watch your child closely for signs of botulism, including poor feeding, loss of head control, difficulty swallowing, or decreased facial expression. Symptoms may appear weeks after consumption. - Seek Medical Attention if Symptoms Appear: If your child shows any signs of botulism, seek immediate medical attention. Physicians can call the California Department of Public Health clinical support line at 510-231-7600 for case consultation, available 24/7. - Clean Contaminated Items: Wash any items and surfaces that may have touched the formula using hot soapy water or place them in a dishwasher to eliminate any remaining bacteria. - Continue Monitoring Even Without Symptoms: If your child consumed ByHeart formula but is not currently showing symptoms, continue monitoring them closely and seek medical attention if symptoms develop at any point. What Did Investigators Find About the Contamination? The investigation revealed complex contamination patterns. Whole genome sequencing (WGS) analysisâa sophisticated genetic testing methodâidentified 17 different strains of Clostridium botulinum in samples from patients, finished products, and ingredients. This genetic diversity made pinpointing a single root cause challenging. Investigators found matching bacterial strains in multiple locations: organic whole milk powder supplied by Dairy Farmers of America (the processor for Organic West Milk, which supplies ByHeart), closed powdered infant formula samples, and clinical isolates from affected infants. However, due to the complexity of Clostridium botulinum and limited scientific evidence currently available, the FDA has not yet determined the specific root cause or causes of the outbreak. What's the FDA Doing Now? The FDA has transitioned from its initial outbreak response activities to post-incident response actions and activities. This includes additional surveillance, prevention efforts, and compliance activities to ensure the safety of powdered infant formula going forward. The agency continues investigating the root cause and will provide updates on its dedicated webpage for Clostridium botulinum illnesses associated with powdered infant formula. Retailers have been instructed to ensure that all recalled ByHeart products are removed from store shelves, including any products that customers have returned. If you see ByHeart formula available for purchase online or in stores, report it to the retailer immediately. Should Parents Be Concerned About Other Formulas? While this outbreak was serious, it affected only one brand and represented a small fraction of the infant formula market. The FDA and CDC's swift investigation and recall prevented additional illnesses. Parents using other infant formula brands should continue following standard safety practices: store formula in a cool, dry place; follow preparation instructions carefully; and discard any formula that appears discolored or has an unusual odor. If you have questions about your child's formula or concerns about your infant's health, contact your pediatrician. They can provide personalized guidance based on your child's medical history and nutritional needs.
