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As the nationwide outbreak of infant botulism continues to grow, and new test results show botulism bacteria in some samples of ByHeart infant formula, the source of the potentially deadly contamination remains unknown.

ByHeart Inc., in an announcement on its website Wednesday night, said that testing the company commissioned has identified Clostridium botulinum, the bacteria that cause botulism, in some samples of its baby formula.

“We do not yet know the root cause, but we are committed to finding the answers,” the company said.

At least 31 infants in 15 states who have been fed ByHeart Whole Nutrition infant formula have been hospitalized with suspect

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