E. coli O26 and (O121) loves flour

I wrote this in May, and it’s still relevant:

I used to be a lick-the-batter-off-the-spoon kind of guy. I stopped doing that a few years ago. I don’t eat raw cookie dough, or let my kids eat it. I’m probably not the most fun dad, but outbreaks recalls like what is going on right now is why.

General Mills announced today a voluntary national recall of five-pound bags of its Gold Medal Unbleached All Purpose Flour with a better if used by date of September 6, 2020. The recall is being issued for the potential presence of E. coli O26 which was discovered during sampling of the five-pound bag product. This recall is being issued out of an abundance of care as General Mills has not received any direct consumer reports of confirmed illnesses related to this product.

This recall only affects this one date code of Gold Medal Unbleached All Purpose Flour five-pound bags. All other types of Gold Medal Flour are not affected by this recall.

Guidance from the Food and Drug Administration (FDA) and the Centers for Disease Control (CDC) continues to warn that consumers should refrain from consuming any raw products made with flour. E. coli O26 is killed by heat through baking, frying, sautéing or boiling products made with flour. All surfaces, hands and utensils should be properly cleaned after contact with flour or dough.

I think they mean cleaned and sanitized.

There’s something about O26 and O121 and flour that we’re all gonna have to figure out.

Here’s the outbreak from May 2019. Here’s a Canadian outbreak from 2017. Oh, here’s another outbreak from 2016.

Salmonella in cake mix: It’s the raw eggs and flour

The U.S. Centers for Disease Control reports in August 2018, two Oregon patients with diagnosed Salmonella infection were interviewed using a standard enteric illness questionnaire; both patients reported having eaten raw cake mix.

Standardized interview questionnaire data collected from 207 Oregon patients with salmonellosis in 2017 indicated a 5% rate of consumption of raw “cake mix or cornbread mix” (Oregon Health Authority, unpublished data, 2017). The binomial probability that both 2018 patients were exposed to raw cake mix by chance was determined to be 0.003, prompting the Oregon Health Authority (OHA) to collect and test the contents of 43 boxes of unopened cake mix of various brands from six retail locations. OHA sent samples to the Institute for Environmental Health Laboratories in Lake Forest Park, Washington, for pathogen testing. Salmonella Agbeni was isolated from an unopened box of white cake mix from manufacturer A, and whole genome sequencing (WGS) data describing the isolate were uploaded to the U.S. National Library of Medicine’s National Center for Biotechnology Information (NCBI) website (https://www.ncbi.nlm.nih.gov/pathogensexternal icon). OHA used the NCBI database to compare sequence data with the cake mix isolate (PNUSAS056022) and then consulted CDC’s System for Enteric Disease Response, Investigation, and Coordination (SEDRIC), a web-based, outbreak investigation tool designed for collaborative, multistate investigations of enteric disease outbreaks.* On October 19, OHA determined that clinical isolates from four patients from Maryland, Ohio, and Wisconsin, with specimen isolation dates ranging from June to September 2018, were genetically related to the Salmonella Agbeni isolate from the unopened box of white cake mix, within four single nucleotide polymorphisms (SNPs).

On October 22, 2018, OHA notified state public health counterparts in the three states of this finding and inquired about raw cake mix exposures among their patients. The Wisconsin patient reported having consumed an entire box of raw white cake mix over several days during the likely exposure period. In addition, WGS analysis indicated that this clinical isolate was closely related genetically (within one SNP) to the isolate cultured from the Oregon white cake mix. On October 25, CDC requested officials in Maryland, Ohio, and Wisconsin to interview patients using a questionnaire with specific questions about baking exposures.

On October 31, the Food and Drug Administration (FDA) initiated an investigation of manufacturer A with regard to the Salmonella-positive white cake mix. In addition to the investigation and document collection, FDA collected samples including an ingredient (flour), finished cake mix, and environmental samples. All collected samples tested negative for Salmonella. On November 5, a voluntary recall of manufacturer A’s classic white, classic butter golden, signature confetti, and classic yellow cake mixes was announced because they might be contaminated with Salmonella bacteria.

On January 14, 2019, CDC declared this outbreak, which totaled seven cases in five states,† to be over (1). This is the first time that OHA used WGS data on the publicly available NCBI website to detect a multistate outbreak associated with a widely distributed consumer product, which resulted in product action. WGS of food and environmental isolates and subsequent analysis on the NCBI and SEDRIC platforms are emerging as useful tools in identifying outbreaks associated with widely distributed products with long shelf lives and low background rates of consumption, such as raw cake mix. Detection of these outbreaks is typically difficult and relies mainly upon epidemiologic evidence from investigation of a larger number of cases (2–4). These efforts also highlight the value of collaboration between public health epidemiologists and laboratorians as well as the use of new technological tools for outbreak detection. During outbreak or cluster investigations, food and environmental samples should be collected as quickly as possible whenever practical, particularly when epidemiologic data suggest an association. WGS, in conjunction with the NCBI website and SEDRIC, can be used to identify genetically related isolates quickly.

US: Notes from the field: Multistate outbreak of salmonella Agbeni associated with consumption of raw cake mix – five states, 2018

30.aug.19

CDC

Stephen G Ladd-Wilson, Karim Morey, et al

https://www.cdc.gov/mmwr/volumes/68/wr/mm6834a5.htm

‘Contamination of wheat poses a foodborne illness risk’

Following up on Chapman’s coverage of the current outbreak of E. coli O26 in flour that has sickened at least 17 people, researchers have concluded that little information is available regarding microbial pathogens in wheat and wheat flour. Information about microbial pathogens in wheat is needed to develop effective methods to prevent foodborne illnesses caused by wheat products.

From 2012 to 2014, we conducted a baseline study to determine the prevalence and levels of pathogens in wheat samples taken before milling. A total of 5,176 wheat samples were tested for enterohemorrhagic Escherichia coli (EHEC), Salmonella spp., Listeria spp., and L. monocytogenes. Positive samples were assayed for most probable numbers (MPNs), and isolates were fingerprinted by pulsed-field gel electrophoresis (PFGE). The rate of detection of each pathogen tested was as follows: Salmonella was in 1.23% of the samples (average level of 0.110 MPN/g), EHECs occurred in 0.44% of the samples (0.039 MPN/g), and Listeria spp. occurred in 0.08% of samples (0.020 MPN/g), but L. monocytogenes was not detected.

The PFGE assessment found a high diversity for all organisms. All EHEC PFGE patterns (22 of 22) were unique, and 39 of 47 Salmonella patterns (83%) were unique. These results indicate a diverse background of naturally occurring organisms. These findings suggest that the microbial contamination is coming from diverse sources and provide no evidence in support of a specific pathogen load. Altogether, our surveillance study shows that contamination of wheat with pathogens is clearly evident and poses a foodborne illness risk.

Occurrence and levels of salmonella, enterohemorrhagic Escherichia coli, and listeria in raw wheat

June 2019

Journal of Food Protection vol. 82 no. 6 pp. 1022-1027

Samuel Myoda, Stefanie Gilbreth, Deann Akins-Leventhal, Seana Davidson, and Mansour Samadpour

https://doi.org/10.4315/0362-028X.JFP-18-345

https://jfoodprotection.org/doi/full/10.4315/0362-028X.JFP-18-345

Beware of the plume: Flour linked E. coli O26 outbreak, Aldi brands recalled

I used to be a lick-the-batter-off-the-spoon kind of guy. I stopped doing that a few years ago. I don’t eat raw cookie dough, or let my kids eat it. I’m probably not the most fun dad, but outbreaks like what is going on right now is why.

Courtesy of the Safe Plates Information Center and NC State Extension

According to CDC,

As of May 24, 2019, 17 people infected with the outbreak strain of E. coli O26 have been reported from 8 states. A list of the states and the number of cases in each can be found on the Map of Reported Cases page.

Illnesses started on dates ranging from December 11, 2018 to April 18, 2019. Ill people range in age from 7 to 86 years, with a median age of 23. Sixty-five percent of ill people are female. Of 17 people with information available, 3 have been hospitalized. No deaths have been reported.

Epidemiologic and laboratory evidence indicates that flour is a likely source of this outbreak.

In interviews, ill people answered questions about the foods they ate and other exposures in the week before they became ill. Of seven people who were interviewed, four (57%) reported eating, licking, or tasting raw, homemade dough or batter. Two people with detailed information reported eating raw dough or batter made with flour or baking mixes from ALDI.

Investigators with the Rhode Island Department of Health collected records and flour samples at a bakery where an ill person reported eating raw dough. Records indicated that the bakery used Baker’s Corner All Purpose Flour from ALDI. The outbreak strain was isolated from an unopened bag of Baker’s Corner All Purpose Flour collected at the bakery.

WGS results showed that the E. coli O26 strain identified in the Baker’s Corner All Purpose Flour sample was closely related genetically to the E. coli O26 strain identified in ill people. These results provide additional evidence that people in this outbreak got sick from eating flour.

On May 23, 2019, ADM Milling Co. and Aldi recalled pdf icon[PDF – 142 KB]external icon 5 lb. bags of Baker’s Corner All Purpose Flour sold at retail locations in the following states because they may be contaminated with E. coli: Connecticut, Delaware, Massachussetts, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Vermont, and West Virginia

I talked to Korin Miller at whattoexpect.com about this outbreak too, and the hidden risk factor in all of this might be cross-contamination.

It’s a good idea to take care when handling raw flour the same way as you would if you were preparing raw meat. That means washing your hands well after you touch it, sanitizing your countertops after you use it and not eating flour products until they’re thoroughly cooked, Chapman says.

Overall, you should definitely take this seriously. “It’s really, really risky to eat raw flour products,” Chapman says.

And I think about this every time I squeeze and plop down a bag of flour in my kitchen. The pathogens, if they are in there, get spread around like shrapnel.

Raw is still risky: Say no to raw dough

My mother used to make and lot of cakes and brownies with her groovy 1960s hand mixer and I always got to lick the beaters.

No more.

And it’s not just the raw eggs, it’s the raw flour.

In June, 2009, an outbreak of shiga-toxin producing E. coli (STEC, primarily O157:H7) in Nestle Toll House cookie dough sickened at least 77 people in 30 American states. Thirty-five people were hospitalized – from cookie dough.

The researchers could not conclusively implicate flour as the E. coli source, but it remains the prime suspect. They pointed out that a single purchase of contaminated flour might have been used to manufacture multiple lots and varieties of dough over a period of time as suggested by the use-by dates on the contaminated product.

The study authors concluded that “foods containing raw flour should be considered as possible vehicles of infection of future outbreaks of STEC.”

So it wasn’t much of a surprise when 63 people fell sick from the outbreak strain of E. coli O121 from Dec. 2015 to Sept. 2016 linked to raw General Mills flour.

There have been about a dozen other flour-related outbreaks. STEC means people – and kids – get quite sick.

Flour is a raw commodity, crops the flour is derived from could be exposed to anything, and testing is so much better than it used to be.

There are some brands of pasteurized flour out there, but people seem to have gotten used to flour as a cheap source of play-dough-like stuff for kids and something to throw at people.

The U.S. Centres for Disease Control says, nope.

This is not a Christmas conspiracy (although I prefer Solstice Season): it’s CDC providing information, like they are supposed to.

People can, and will, do what they want.

As Maggie Fox of NBC reports, “Do not taste or eat any raw dough or batter, whether for cookies, tortillas, pizza, biscuits, pancakes, or crafts made with raw flour, such as homemade play dough or holiday ornaments,” the CDC advises.

“Do not let children play with or eat raw dough, including dough for crafts.”

Handling food, including flour, requires care and hygiene.

“Keep raw foods such as flour or eggs separate from ready-to eat-foods. Because flour is a powder, it can spread easily,” the CDC notes. “Follow label directions to refrigerate products containing raw dough or eggs until they are cooked. Clean up thoroughly after handling flour, eggs, or raw dough.”

Flour power: NEJM paper on 2016 outbreak

A couple of weeks ago Duncan Hines brand cake mixes were recalled because of Salmonella. Maybe it was the flour. Flour comes from dried wheat that’s milled and not heat treated (because it messes with the gluten). As the Salmonella dries out it gets hardier and survives for months (or longer).

In 2016 pathogenic E. coli (both O121 and O26 serogroups) was the culprit in another raw flour outbreak. The good folks involved with that investigation (Crowe and colleagues) published their findings this week in the New England Journal of Medicine.

The outbreak began in December 2015 and lasted through to September 2016. Fifty-six cases in 22 states were identified.

The biggest takeaway for me was this (such a great explanation of how an investigation works):

Open-ended telephone interviews then were conducted with 10 patients, all of whom stated that they baked frequently or regularly consumed home-baked foods. Five of the patients recalled baking during the week before illness onset, and 3 others reported thatthey might have baked during that period. Of the 5 case patients who remembered baking, 4 reported eating or tasting homemade batter or dough, 3 of whom used brand A flour. The fourth used either brand A or another brand. Two of the patients (a resident of Colorado and a resident of Washington) still had the bags of brand A flour that they had used in the week before illness onset.

Shortly thereafter, state investigators identified 3 ill children who had been exposed to raw flour at restaurants in Maryland, Virginia, and Texas. Restaurant staff had given them raw dough to play with while they waited for their food to be served.

Folks in the media or the hockey arena often ask how these outbreaks get solved. This is how – lots of interviewing, hypothesis generating and then a case-case or case-control analysis. It’s part detective work, part statistics and all science. Sometimes the interviews are messy but this one shows what happens when it works.

Trace-back investigation of the two bags of brand A flour collected from patients in Colorado andWashington revealed that the flour from Colorado was unbleached all-purpose flour manufactured on November 14, 2015, and the flour from Washington was bleached all-purpose flour manufactured on November 15, 2015. The two bags were produced in the same facility. The flour that was used in the raw dough given to the children exposed in the Maryland, Virginia, and Texas restaurants also was from this facility, as was flour from three additional bags collected from case patients residing in Arizona, Califor- nia, and Oklahoma.

Happy birthday Sam, no, you can’t eat the batter

My youngest kid is 8 today. He’s the funniest, cutest and most charming of any of us.

And he knows it.

He pretty much gets away with everything. Last year during the annual parent/teacher conference his teacher told us, sure, he talks all the time, he distracts other kids, but how can you discipline him? ‘He’s Sam’.

Today, this budding mite hockey player has practice, donuts with his teammates and then we’e going home for pizza and cake.

As Dani was making the cake earlier today I checked to see whether it was Duncan Hines. Although we’ve long outlawed eating cookie dough and licking the mixing bowl in our house, I still didn’t want to use the stuff that was recalled yesterday after being linked to five cases of Salmonella Agbeni.

From FDA’s website:

The FDA is investigating the manufacturing facility that made recalled Duncan Hines cake mixes.

FDA and the CDC informed Conagra Brands that a sample of Duncan Hines Classic White Cake Mix that contained Salmonella Agbeni matched the Salmonella collected from ill persons reported to the CDC. This was determined through Whole Genome Sequencing, a type of DNA analysis.

Based on this information, Conagra Brands is working with FDA to proactively conduct a voluntary recall of Duncan Hines cake mixes from the market. The FDA is conducting an inspection at the Conagra Brands-owned manufacturing facility that produced the cake mixes. The FDA is also collecting environmental and product samples.

Recommendation:

Consumers should not bake with or eat the recalled product. Additionally, consumers should not eat uncooked batter, flour, or cake mix powder.

Salmonella in low moisture foods continues to be an issue. As the Salmonella dries out it gets hardier and survives for months (or longer). Flour (if that’s the source) comes from dried wheat that’s milled and not heat treated (because it messes with the gluten. Salmonella or E. coli from wheat fields can make it to cake batter fairly easily.

Flour power: Raw is risky

When I was a kid, I had this multi-colored swim towel that stated Flower Power (right, not exactly as shown).

I should have known that if a 1960s slogan had been co-opted by towel manufacturers in the early 1970s, it was a sign of corporate greed rather than earth-tone sentiment.

For the past decade, raw flour has increasingly come under the food safety microscope.

Flour was suspect in a 2008 outbreak of Salmonella in New Zealand. In June, 2009, an outbreak of shiga-toxin producing E. coli (primarily O157:H7) in Nestle Toll House cookie dough sickened at least 77 people in 30 American states. Thirty-five people were hospitalized – from flour in the cookie dough.

Hemp seed flour sickened 15 Germans in 2010.

There was the U.S. General Mills outbreak of 2016 which sickened at least 56 people with the outbreak strain of E. coli O121 and O26, followed by a separate outbreak of E. coli O121 in Robin Hood flour in Canada in late 2016 going into 2017, that sickened at least 29.

It’s this latter outbreak that has journalist Jim Romahn’s attention.

Romahn writes the release of 759 pages of mostly e-mails indicates there was a massive effort involved in a recall of flour milled in Saskatoon that was contaminated with E. coli O121.

Twenty-two Canadians were identified as sickened by the flour, including one key case where the person consumed raw dough.

With hindsight, health officials were able to determine the first person sickened was Nov. 13, 2016. The others sickened and linked to the flour were between then and Feb. 26, 2017.

Robin Hood flour was identified as the source in March and on March 26 the Canadian Food Inspection Agency began a recall that eventually grew to scores of brand-name products across Canada and even an export shipment to Guyana.

The recall involved a number of major companies, such as Smucker Foods of Toronto and the Sobeys supermarket chain.

There were some unusual difficulties, including the challenge of contacting Mennonites who have no telephones.

The investigation and lab results eventually traced the source to flour milled at Ardent’s Saskatoon plant on Oct. 15, 16 and 17.

A high percentage of packages of flour milled on those dates turned up with E. coli O121.

But even then it’s not clear where the wheat originated.

Ardent Mills said it was probably spring wheat, but it could have also contained soft wheat, and that it probably was from the 2016 harvest, but might have had some wheat from the 2015 harvest.

That’s reflective of the amount of blending that happens both with the wheat used in milling and the flours that are blended into products for sale.

The documents were released under Access to Information at the request of a woman who spent time in a hospital in Medicine Hat, Alta.

 An Outbreak of Shiga Toxin–Producing Escherichia coli O121 Infections Associated with Flour – Canada, 2016–2017

MMWR Morb Mortal Wkly Rep 2017; 66: 705–706

Morton V, Cheng JM, Sharma D, Kearney A.

Bob’s Red Mill Natural Foods gets Salmonella, and thinks it’s important to capitalize to push BS

The press release from Bob’s reads like this:

Bob’s Red Mill Natural Foods is voluntarily recalling 2,099 cases of Organic Amaranth Flour (22 oz.), after recent testing revealed the presence of Salmonella in a single LOT of Organic Amaranth Flour (22 oz.) with a Sell By date of Nov. 26, 2015.

The recalled Organic Amaranth Flour (22 oz.) was distributed through retailers and distributors nationwide. This product and LOT was distributed in CA, FL, MI, ND, N, NY, OH, OR, TX, and WA starting June 11, 2014 and ended shipping on August 7, 2014

The recalled product is Organic Amaranth Flour (22 oz.) with a Sell By Date of 11/26/2015, LOT: 169617, which can be found on the side of the package, near the top of the panel. UPC: 0 39978 00911 1

While this product expired in November 2015, this product was found on the shelves of one retail store, and thus Bob’s Red Mill is recalling the product out of an abundance of caution.

How cautious is it to sell flour with shit three years past expiration?

E. coli: Flour fights not such a good idea

In June, 2009, an outbreak of shiga-toxin producing E. coli (primarily O157:H7) in Nestle Toll House cookie dough sickened at least 77 people in 30 American states. Thirty-five people were hospitalized – from cookie dough.

The researchers could not conclusively implicate flour as the E. coli source, but it remains the prime suspect. They pointed out that a single purchase of contaminated flour might have been used to manufacture multiple lots and varieties of dough over a period of time as suggested by the use-by dates on the contaminated product.

The study authors concluded that “foods containing raw flour should be considered as possible vehicles of infection of future outbreaks of STEC.”

So it wasn’t much of a surprise when 56 people fell sick from with the outbreak strain of E. coli O121 from Dec. 2015 to Sept. 2016 were linked to raw General Mills flour.

The peer-reviewed summary of the outbreak investigation was published last week in The New England Journal of Medicine.

Abstract below:

In 2016, a multijurisdictional team investigated an outbreak of Shiga toxin–producing Escherichia coli (STEC) serogroup O121 and O26 infections linked to contaminated flour from a large domestic producer.

Methods

A case was defined as infection with an outbreak strain in which illness onset was between December 21, 2015, and September 5, 2016. To identify exposures associated with the outbreak, outbreak cases were compared with non-STEC enteric illness cases, matched according to age group, sex, and state of residence. Products suspected to be related to the outbreak were collected for STEC testing, and a common point of contamination was sought. Whole-genome sequencing was performed on isolates from clinical and food samples.

Results

A total of 56 cases were identified in 24 states. Univariable exact conditional logistic-regression models of 22 matched sets showed that infection was significantly associated with the use of one brand of flour (odds ratio, 21.04; 95% confidence interval [CI], 4.69 to 94.37) and with tasting unbaked homemade dough or batter (odds ratio, 36.02; 95% CI, 4.63 to 280.17). Laboratory testing isolated the outbreak strains from flour samples, and whole-genome sequencing revealed that the isolates from clinical and food samples were closely related to one another genetically. Trace-back investigation identified a common flour-production facility.

Conclusions

This investigation implicated raw flour as the source of an outbreak of STEC infections. Although it is a low-moisture food, raw flour can be a vehicle for foodborne pathogens.

Shiga toxin–producing E. coli infections associated with flour

N Engl J Med 2017; 377:2036-2043, November 23, 2017, DOI: 10.1056/NEJMoa1615910

Samuel J. Crowe, Ph.D., M.P.H., Lyndsay Bottichio, M.P.H., Lauren N. Shade, B.S., Brooke M. Whitney, Ph.D., Nereida Corral, M.P.H., Beth Melius, M.N., M.P.H., Katherine D. Arends, M.P.H., Danielle Donovan, M.S., Jolianne Stone, M.P.H., Krisandra Allen, M.P.H., Jessica Rosner, M.P.H., Jennifer Beal, M.P.H., Laura Whitlock, M.P.H., Anna Blackstock, Ph.D., June Wetherington, M.S., Lisa A. Newberry, Ph.D., Morgan N. Schroeder, M.P.H., Darlene Wagner, Ph.D., Eija Trees, D.V.M., Ph.D., Stelios Viazis, Ph.D., Matthew E. Wise, M.P.H., Ph.D., and Karen P. Neil, M.D., M.S.P.H.

http://www.nejm.org/doi/full/10.1056/NEJMoa1615910