It’s all so confusing. There’s a cluster of E. coli O121 in Canada. Sort of a big one. 24 people ill in four provinces (British Columbia, Saskatchewan, Alberta and Newfoundland and Labrador) going back to November 2016.

These illness came on the tail end of another E. coli O121 outbreak in the U.S. linked to Gold Medal brand all purpose flour.

Today, CFIA (that’s the Canadian Food Inspection Agency for those following along at home) announces a recall of Robin Hood brand all purpose flour distributed in four provinces (Alberta, British Columbia, Manitoba, Saskatchewan) due to E. coli O121 contamination – linked to one illness.

In the new world of whole genome sequencing it would seem easy to say whether these clusters are linked – or totally different. And is the single illness CFIA reports part of the E. coli O121 cluster? Is it different?

My head hurts.

Earlier this year Natalie Seymour and I organized a workshop on STEC in flour. Karen Neil of CDC, Tim Jackson from Nestle and Scott Hood from General Mills spoke about challenges in flour food safety. The workshop focused on stuff like, there’s no kill step in the milling process, there’s literally tons of commingling and although it’s not intended to be eaten raw – sometimes it is (in cookie dough, cake mix).

And a risk factor in the 2016 Gold Medal-linked outbreak was kids handling raw tortilla and pizza dough in restaurants.

There’s some other stuff known about flour – generic E. coli species have been found in flour in NZ.

A survey conducted on wheat and flour milling in Australia showed no detectable Salmonella, 3.0 MPN/g of generic E. coli and 0.3 MPN/g of B. cereus recovered on average from 650 samples (from two mills).

And a US study found generic E. coli in 12.8% of commercial wheat flour samples examined.

So, yeah, flour.