Federal officials identified the current, ongoing outbreak of E. coli in February, but it took until late April for investigators to find the common denominators that led to General Mills’ recall of 10 million pounds of flour yesterday. As of this afternoon, 38 people across 20 states have been confirmed with the outbreak strain of E. coli O121, according to the Centers for Disease Control and Prevention. Ten of the victims required hospitalization, but none have developed hemolytic uremic syndrome, a type of kidney failure, and no deaths have been reported. None of the product samples tested by state or federal officials — or by General Mills Inc. — have returned positive results for E. coli O121, according to a CDC spokeswoman and Mike Siemienas, General Mills brand manager. “CDC and FDA (Food and Drug Administration) had several calls with General Mills during the course of the investigation to provide them with information about our investigation so the company could help us,” the CDC spokeswoman told Food Safety News. “Based on preliminary information we had about a potential link, calls with General Mills began in late April. … PulseNet identified the outbreak in February. At that time there were 14 cases.” Siemienas said Wednesday that most of the flour being recalled was produced at the General Mills facility in Kansas City, MO.

“CDC has been working on tracking these cases for some time,” Siemienas said. “As soon as we learned of a possible linkage to flour, we launched an immediate investigation. To date, we have found no presence of E. coli O121 in the flour production facilities or in any General Mills flour product.” On Tuesday, General Mills recalled several sizes and varieties of Gold Medal Flour, Gold Medal Wondra Flour and Signature Kitchens Flour because of possible E. coli contamination. Outbreak investigation details A combination of E. coli DNA patterns in CDC’s PulseNet database and patient interviews allowed public health investigators to identify the outbreak and it’s likely cause. “Preliminary results of this investigation indicate an association between (E. coli) O121 infection and someone in the household using Gold Medal brand flour to make something to eat,” the CDC reported this afternoon. “Federal and state and local regulatory officials performed traceback investigations using package information collected from ill people and records collected from restaurants where ill people were exposed to raw dough. These investigations indicated that the flour used by ill people or used in restaurant locations was produced in the same week in November 2015 at the General Mills facility in Kansas City, MO.” CDC officials stressed that the outbreak investigation is ongoing, but based on information collected so far, “flour produced at General Mills’ Kansas City, MO,facility is a likely source of this outbreak.” “Illnesses started on dates ranging from Dec. 21, 2015, to May 3, 2016. Ill people range in age from 1 year to 95, with a median age of 18,” according to the CDC outbreak announcement. Additional victims could be identified because it takes several weeks for illnesses to be reported to officials after an E, coli infection is diagnosed, CDC reported. Of 21 victims, 16 reported that they or someone in their household used flour in the week before they became ill.  Of 22 victims, nine reported eating or tasting raw homemade dough or batter before becoming ill. A dozen of 22 victims reported using Gold Medal brand flour. Three victims reported eating or playing with raw dough at restaurants, according to the CDC. As of May 31, the states with 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.)