The US Centers for Disease Control and Prevention (CDC) is investigating a multistate outbreak of Shiga toxin-producing E. coli O121 (STEC O121) infections that has been linked to flour produced at the General Mills facility in Kansas City, Missouri.
The first cases became ill in late December 2015 and the outbreak has so far affected at least 38 people in 20 states, with ten requiring hospital treatment. No cases of haemolytic uraemic syndrome (HUS) have been reported to date. Genetic analysis of isolates from ill people by whole genome sequencing (WGS) revealed that they were closely related and therefore likely to originate from a common source of infection.
In interviews a number of sick people reported consuming raw dough or batter made using Gold Medal brand flour at home, or at restaurants. Epidemiological evidence and traceback investigations point to flour produced in a single week at the General Mills facility in Kansas City as the likely vehicle of infection.
The company voluntarily recalled various sizes and varieties of flour sold under the Gold Medal, Gold Medal Wondra and Signature Kitchens brands on 31 May, because of possible E. coli contamination. However, STEC O121 has not been isolated from samples of the flour or from the manufacturing facility to date. General Mills has also warned consumers not to consume raw products made with flour and to wash hands after contact with raw dough or flour.