WASHINGTON — Some infants affected by a major contaminated infant formula outbreak last year continue to experience health issues months after their initial illness, federal health officials said on Thursday.
The outbreak of infant botulism linked to ByHeart Whole Nutrition powdered infant formula sickened dozens of babies across multiple states in 2025, with all cases requiring hospitalization. The Centers for Disease Control and Prevention declared the outbreak over in February 2026, but follow-up data indicate that recovery for some infants has extended well beyond initial treatment.
Health authorities reported 48 cases, including 28 confirmed and 20 probable, associated with the formula. No deaths occurred. Infants ranged in age from several weeks to several months at the time of illness onset.
Many infants received BabyBIG, the botulism immune globulin treatment, which shortened hospital stays but did not eliminate the need for extended recovery in some cases. Hospital stays had a median of eight days, though some with severe symptoms remained hospitalized for more than a month.
"Although many infants are now progressing in their recovery, evaluating their outcomes is essential to understanding the progression and severity of illness observed during this outbreak," Myra Brooks of the CDC's Epidemic Intelligence Service said in a presentation earlier this year.
Recovery from infant botulism can take weeks to months as nerves heal, with some infants requiring physical therapy and additional medical support after discharge. Officials have noted that while most make a full recovery, prolonged weakness or other effects can persist in certain cases.
The FDA linked the contamination to Clostridium botulinum in the formula, with testing confirming the bacteria in some samples. ByHeart issued a voluntary recall of all its infant formula products. Investigations into the root cause, including potential issues with milk powder ingredients, continued into 2026.
A separate, smaller outbreak involving Nara Organics formula was reported in June 2026, affecting three infants in California, Pennsylvania and Washington, but details on long-term outcomes for those cases remain limited as investigations are ongoing.
Health officials continue to monitor affected infants and advise parents to avoid recalled products. The FDA and CDC have emphasized proper formula preparation and storage to prevent future risks.
As of Thursday, federal authorities said assessments of long-term impacts from the 2025 outbreak were still underway, with no comprehensive final data on all cases immediately available. Affected families have been receiving follow-up care through state health departments and pediatric specialists.
