FDA Investigation Into Infant Botulism Outbreak Yields No Root Cause

The Food and Drug Administration (FDA) has concluded its post-outbreak response activities for an infant botulism outbreak without identifying the root cause of contamination. The outbreak, linked to infant formula produced by ByHeart, sickened 48 infants across 17 states. The agency stated its investigation into the root cause is ongoing, with a focus on ingredients.

The outbreak was first identified in early November and declared over on February 26 by the FDA and the Centers for Disease Control and Prevention (CDC). Infants hospitalized with the life-threatening infection are still recovering months later. The investigation traced the bacterium, Clostridium botulinum, to ByHeart's formula.

Strains of C. botulinum from sick infants were genetically linked to strains found in ByHeart's formula. These were also linked to powdered whole milk used in the formula. Dairy Farmers of America produced the powdered milk at a Nevada facility. The liquid milk originated from Organic West, a California-based supplier.

The FDA traced contaminated formula and milk powder to eight whole milk lot powders. These powders came from 33 fluid milk lots from Organic West. Despite this detailed tracing, the FDA could not determine where or how the bacteria entered the production chain. The agency concluded that investigational findings could not identify the source or root cause of contamination.

Three companies involved in the investigation have not publicly taken responsibility for the contamination. ByHeart stated that the FDA did not identify deficiencies in its facilities that could explain the root cause. Organic West previously maintained that nothing had been proven about its milk. Dairy Farmers of America stated that manufacturers of end-use consumer products are responsible for processing ingredients to ensure product safety.

ByHeart announced it is working with a laboratory to develop more sensitive testing for C. botulinum in its products. The company is also working to resume infant formula production.