As authorities probe over 30 cases of infant botulism linked to ByHeart baby formula since August, parents say their children fell ill months earlier and are seeking answers.

California health officials confirmed that six infants who consumed ByHeart formula were treated for botulism between November 2024 and June 2025—up to nine months before the outbreak that has now affected at least 31 babies across 15 states. At the time, officials said there was insufficient evidence to link the cases to a common source. They still cannot connect pre-August illnesses to the current outbreak.

Parents of at least five affected infants shared their experiences with The Associated Press through attorney Bill Marler. Amy Mazziotti of Burbank said her 5-month-old son, Hank, was hospitalized in March 2025 after consuming ByHeart formula. Similarly, Katie Connolly of Lafayette reported that her 8-month-old daughter, M.C., fell ill in April following formula feedings. Both mothers initially had no clue about the infection source, which is typically environmental or linked to honey.

ByHeart issued a nationwide formula recall on Nov. 11. Tests of unopened cans confirmed contamination with the bacteria that causes infant botulism. Other pre-outbreak cases reportedly involved ByHeart formula, though linking them definitively to the current outbreak is complicated due to missing lot numbers and discarded cans.

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CDC officials said their focus remains on the surge of cases since August, though earlier illnesses might be connected. Experts argue these earlier cases should be counted as part of the outbreak given the link to ByHeart.

Both Mazziotti and Connolly said their children are improving, but the experience has left lingering effects. Connolly emphasized the need for transparency: “We deserve to know the data that can help us understand how our babies got sick.”

Source: AP