In this week's MMWR, CDC reviews the 2016 outbreak or E. coli O157:H7 associated with a dough mix. There were 13 people in 9 different states who became ill. Eight of those people were hospitalized, and two developed HUS (hemolytic uremic syndrome - a condition that can lead to loss of kidney function). 8 of these individuals ate a desert pizza made iwht the mix while one other ate bread sticks made with that dough.
Government inspectors sampled 88 samples of the dough mix at the restaurants and 6 samples of the dry dough mix at the manufacturer and did not find this strain of E. coli, (although strains of identified non-O157 STEC were found.)
Flour is a raw agricultural commodity, and while level of pathogens such as E. coli and Salmonella are normally very low, there are times when sufficient pathogens can be present to cause illness. While it seems not one was affected from eating the pizza with this dough, the investigators felt that the thicker desert pizza may not have been cooked as thoroughly. And when people spread flour on surfaces, such as when working dough, this flour may then get upon other foods.
It is important for not only consumers, but also foodservice operations to treat flour as potentially contaminated. This means cooking dough thoroughly, cleaning up spilled flour as well as flour spread on surfaces so that it does not come in contact with ready-to-eat foods, and of course, not eating raw dough.
CDC - MMWR
https://www.cdc.gov/mmwr/volumes/66/wr/mm6603a6.htm?s_cid=mm6603a6_e
Notes from the Field: Multistate Outbreak of Escherichia coli O157:H7 Infections Linked to Dough Mix — United States, 2016