General Mills Inc. and federal officials have been working together to account for recalled flour that has been linked to an E. coli outbreak and that was sent to food producers in addition to retailers and restaurants. Neither the company nor government has included information about the flour sent to food producers in published recall or outbreak notices. General Mills recalled 10 million pounds of flour Tuesday after the Centers for Disease Control and Prevention (CDC) informed the company the flour had been linked to an E. coli outbreak that has been going on since December 2015. Both General Mills and the U.S. Food and Drug Administration confirmed for Food Safety News this week that some of the recalled flour had been sent in bulk to food producing companies. “Yes, and they have been notified of the recall,” General Mills spokesman Mike Siemens said when asked whether the recalled flour was sold to food producers, bakeries, etc., or used in other General Mills products, such as baking mixes. “We are not aware of it being used in any dry mixes,” Siemens said, but he did not provide comment on any other kinds of products. A spokeswoman for the FDA’s Office of Foods and Veterinary Medicine said the agency’s Coordinated Outbreak Response and Evaluation (CORE) Network did not include information in its outbreak notice about the flour sent to food producers because it would not have had meaning for the general public. “FDA worked with General Mills to directly notify their bulk customers and facilitate the recall. This information is not included in the CORE posting because consumers would not be able identify the bulk General Mills products because they are not sold in stores,” FDA’s Evelyn Pereira said in an email. Pereira said the agency could not comment on the likelihood of secondary recalls for products that may have been produced with the recalled flour, which was mostly produced in General Mills’ facility in Kansas City, MO. “FDA cannot speculate about future recalls, but we will work with any downstream customers in facilitating potential recalls or other actions,” Pereira said. If the flour was used by producers for foods that are not baked or otherwise cooked before sale to consumers — such as raw cookie dough, pizza dough or pie crusts — there could be secondary recalls in the works. Raw cookie dough from the Nestle Co. was linked to a 2009 E. coli O157:H7 outbreak that sickened 77 people across 30 states. Nestle recalled 3.6 million packages of chocolate chip cookie dough. After the outbreak, the company started heat treating flour to kill pathogens before it is used in Nestle products. Outbreak and investigations then and now A CDC epidemiologist who helped trace the current 20-state E. coli O121 outbreak to General Mills’ flour also worked on the 2009 E. coli outbreak investigation that was ultimately linked to the flour in Nestle’s cookie dough.

Dr. Karen Neil, a medical epidemiologist with CDC’s Outbreak Response and Prevention Branch, said Thursday that both investigations were challenging. She said CDC’s PulseNet system and database allowed for the current outbreak to be detected relatively quickly. The first person became ill Dec. 21, 2015, and the outbreak investigation began in early February. “The way we detect outbreaks is PulseNet and there is an inherent delay because of the lag time between when people become ill and when the information is reported and uploaded,” Neil said, adding it takes a minimum to three to four weeks for that process when the pathogen involved is E. coli. Neil said state and federal health officials started out interviewing outbreak victims with standard questionnaires, asking about consumption of the usual suspect foods for E. coli infection, such as leafy greens or ground beef. When the investigation went no where, the epidemiologists and other public health officials stepped back. They reinterviewed victims with open-ended questions about what food they had eaten and handled before becoming ill. “In this investigation the restaurant-related cases really helped,” Neil said. “When we started hearing things about raw dough, the home bakers weren’t sure what brand of flour they had used because they didn’t still have the packages. There was nothing to trace from.” Neil said when some outbreak victims reported eating and handling raw dough at restaurants before becoming ill, it was a break through moment in the investigation. It gave investigators another route to trace back to possible sources. “In this instance Whole Genome Sequencing was helpful, too, because when we compared the (lab samples from) restaurant cases with the cases involving home bakers, they had the same strain (of E. coli),” Neil said. None of the flour samples tested thus far by FDA and General Mills have returned positive results for the outbreak strain. But Neil said the traceability information from restaurants that purchased General Mills flour, plus more than half of interviewed victims reporting they had used one of the recalled brands, provided sufficient evidence for the product to be linked to the outbreak. “It has been a really challenging investigation because flour is an ingredient in other foods and people don’t think about the fact that they’ve eaten it,” Neil said. Neither FDA nor CDC has closed their investigations into the outbreak cause, and CDC officials said in their outbreak announcement that additional victims will likely be identified.

Advice to consumers Neil said she and other public health officials are very concerned that consumers may still have the recalled flour in their homes because of its long shelf life. Some of the retail packages available to consumers — sold under the Gold Medal, Gold Medal Wondra and Signature Kitchens brands — have best-by date codes reaching into July 2017. The shelf life of the bulk flour distributed to food producers has not been published. “It is very important for people to never eat raw dough or batter,” Neil said, repeating the CDC warning about flour having the inherent possibility to be contaminated because it is made from wheat, which is grown outdoors, and not subjected to a kill step during production. “Also, if people do have the recalled flour in their homes, they should not use it. They should throw it away and throughly wash the container it was in and anything that came into contact with it.” Neil said even if consumers plan to use the flour in baking or cooking that would provide a kill step, the flour can very easily cross-contaminate utensils, surfaces and other foods during preparation. As of May 31, the states with confirmed outbreak patients were: Alabama 1, Arkansas 1, Arizona 2, California 1, Colorado 4, Iowa 1, Illinois 4, Massachusetts 2, Maryland 1, Michigan 4, Minnesota 3, Missouri 1, Montana 1, New York 1, Oklahoma 2, Pennsylvania 2, Texas 2, Virginia 2, Washington 2 and Wisconsin 1. (To sign up for a free subscription to Food Safety News, click here.)