Forty-eight infants across 17 states were hospitalized after drinking spore-contaminated baby formula, and months after the outbreak was declared over, federal regulators still do not know how the contamination started.
According to a report by Ars Technica, the Food and Drug Administration this week posted what critics are calling an underwhelming epilogue to the investigation. The agency traced the bacteria through a chain of suppliers but stopped short of identifying a root cause. "The FDA's investigation into the root cause is ongoing with a focus on ingredients," the agency reported.
The outbreak was identified in early November and declared over by the FDA and the Centers for Disease Control and Prevention on February 26. Some of the infants who were sickened are still recovering months after contracting the life-threatening infection.
The bacteria at the center of the investigation is Clostridium botulinum, which produces hardy spores found in soil and sediments. When those spores reach the vulnerable, underdeveloped gut of an infant, they can grow and release a neurotoxin that causes flaccid paralysis.
Investigators were able to trace the contamination through several steps in the supply chain. Strains of the bacteria found in some sick infants were genetically linked to strains found in ByHeart's formula. Those strains were also linked to powdered whole milk used in that formula. The powder was dried from liquid milk at a Nevada facility run by Dairy Farmers of America. That liquid milk came from a California supplier called Organic West, which then sold the resulting powder to ByHeart.
The FDA traced contaminated formula and milk powder back to eight whole milk lot powders that came from 33 fluid milk lots from Organic West. Despite that detailed trail, regulators have not been able to say where along that path the spores first entered the product.
Three companies at the center of the investigation have been left pointing fingers at each other, with none publicly taking responsibility for the contamination. The FDA has not said when it expects to complete the root cause investigation or what regulatory steps might follow.
