Baking Flour Stirs Up Controversy in Multistate E coli Outbreak

Bakers beware—the US Centers for Disease Control and Prevention (CDC) has announced a multistate E coli O26 outbreak likely linked to all-purpose flour sold at ALDI locations.

As of May 24, 2019, 17 people infected with the outbreak strain have been documented across 8 states. Whole genome sequencing conducted on bacteria isolated from ill individuals showed that they were closely related genetically, which indicates that the ill involved in this outbreak are more likely to share a common source of infection.

The ill individuals range in age from 7 to 86 years with a median age of 23 years, and 65% are female. Thus far, 3 individuals have been hospitalized and no deaths have been reported at this time.

Seven people were interviewed about their exposures prior to falling ill and 4 reported eating raw homemade dough or batter. Further, 2 individuals reported eating raw dough or batter made from flour or baking mixes from ALDI.

Investigators with the Rhode Island Department of Health collected records and flour samples at a bakery where an ill person reported eating raw dough, following a confirmed case of E coli in the state. The bakery used Baker’s Corner All-Purpose Flour from ALDI, and an isolate collected from an unopened bag of the flour was found to contain the outbreak strain.

Whole genome sequencing revealed that the E coli O26 strain identified in the Baker’s Corner All-Purpose Flour sample was closely related genetically to the E coli O26 strain identified in the ill individuals, providing further evidence that the individuals in this outbreak got sick following consumption of flour.

Onset of illness dates range from December 11, 2018, through April 18, 2019. Illnesses that are a part of this outbreak may not be reported yet due to the 2- to 3-week timeline associated with reporting E coli infections. Public health officials are using the PulseNet system to identify illnesses that may be linked to this outbreak.

On May 23, 2019, ALDI, in association with ADM Milling Co, issued a recall for 5-pound bags of Baker’s Corner All Purpose Flour sold at retail locations in select states because of possible contamination with E coli.

This is an ongoing investigation and the US Food and Drug Administration is working to determine whether other brands or lots of flour may be potentially contaminated.

At this time the CDC warns clinicians that antibiotics are not recommended for patients with suspected E coli infections until diagnostic testing can be performed. Research has shown that administering antibiotics to patients with E coli infections might increase their risk of developing hemolytic uremic syndrome, and a benefit of treatment has not been clearly demonstrated.

The CDC will continue to provide updates as they become available.

For the most recent case counts in the E coli outbreak linked to baking flour, check out the Contagion® Outbreak Monitor.