Wheat flour has recently been recognised as an exposure vehicle for the foodborne pathogen Shiga toxin-producing Escherichia coli (STEC). Wheat flour milled on two sequential production days in October 2016, and implicated in a Canada wide outbreak of STEC O121:H19, was analysed for the presence of STEC in November 2018.
Stored in sealed containers at ambient temperature, the water activity of individual flour samples was below 0.5 at 6 months post-milling and remained static or decreased slightly in individual samples during 18 months of additional storage. STEC O121 was isolated, with the same genotype (stx2a, eae, hlyA) and core genome multilocus sequence type as previous flour and clinical isolates associated with the outbreak. The result of this analysis demonstrates the potential for STEC to persist in wheat flour at levels associated with outbreak infections for periods of up to two years. This has implications for the potential for STEC to survive in other foods with low water activity.
Shiga toxin-producing Escherichia coli survives storage in wheat flour for two years
This study was conducted to validate a simulated commercial baking process for plain muffins against E. coli O121 (isolated from the recent illness outbreak associated with flour), and compare the thermal inactivation parameters (D- and z-values) of cocktails of four isolates of E. coli O121 and three serovars of Salmonella (Newport, Typhimurium, and Senftenberg) in muffin batter.
Flour samples were spray inoculated with the E. coli O121 or Salmonella cocktails, dried back to the pre-inoculation weight to achieve ~7 log10 CFU/g, and used to prepare muffin batter. For the muffin baking validation study using E.coli O121, muffin batter was baked at 375 °F (190.6 °C) oven temperature for 21 min followed by 30 min of ambient cooling. The E. coli O121 population decreased by >7 log10 CFU/g in muffins by 17 min of baking, and was completely eradicated after 21 min of baking and ambient cooling. The D-values of E. coli O121 and Salmonella cocktails in muffin batter at 60, 65 and 70 °C were 42.0 and 38.4, 7.5 and 7.2, and 0.4 and 0.5 min, respectively; whereas the z-values of E. coli O121 and Salmonella were 5.0 and 5.2 °C, respectively.
Comparison of survival and heat resistance of Escherichia coli O121 and salmonella in muffins
I have so many Larry stories that I’d probably get sued now that he’s a big shot.
But when I was teaching him and Kevin, about 1995 (I may have noticed Chapman joined my lab about 1999, it’s all a purple haze, but I got those 70 peer-reviewed papers out and made full-professor) so here’s Larry, now that he’s returned to Guelph (that’s in Ontario, Canada) and maybe you have a chat with Malcolm, see about getting my $750,000 returned and we can do some fun research.
Despite appearances, experts say a recent rise in major recalls is not a sign of food supply problems, but the result of a more active investigative body and better testing tools — though they add more can be done.
“This is proof that the system is working well,” said Lawrence Goodridge, a professor focusing on food safety at The University of Guelph, speaking about the recent meat recall.
Yet, he believes that “in Canada, we have to get to a place where we can actually stop the food from going to retail in the first place.”
Since Sept. 20, a investigation by the Canadian Food Inspection Agency into possible E. coli 0157:H7 contamination in some beef and veal products sold by Ryding-Regency Meat Packers Ltd. and St. Ann’s Foods Inc. has led to the recall of nearly 700 products.
The CFIA suspended the Canadian food safety license for St. Ann’s meat-processing plant, as well as Ryding-Regency’s slaughter and processing plant, both in Toronto, in late September.
No illnesses have been reported in association with the products, according to the CFIA, but symptoms of sickness can include nausea, vomiting, abdominal cramps.
Emma Broadhurst was six months pregnant when she flew out to Turkey with friends for a 7-night stay at the Crystal Sunset Luxury Resort and Spa, east of the city of Antayla, at the start of September.
But, according to Andy Rudd of The Mirror, within days of arriving she fell unwell suffering from chronic diarrhea and became dehydrated and lost weight.
Just over 24 hours later her best friend’s seven-year-old son, Kailan, also fell ill with diarrhea and on their return to the UK his mum, Emma McComb, fell ill and Kailan was left ‘screaming in agony’ and projectile vomiting.
All three, who shared a room while on holiday, were then diagnosed with salmonella poisoning after stool samples were sent for testing by their local GP, claims Emma.
The friends stayed in the same hotel where two-year-old Allie Birchall and her family holidayed before little Allie was taken ill before passing away having contracted E. coli.
All members of her family, from Wigan, Greater Manchester, suffered from gastric symptoms including stomach cramps and diarrhoea during their 10-day stay with Jet 2.
Allie’s condition became so severe she was rushed to hospital after the family returned to the UK.
Her parents had to make the heartbreaking decision to switch off her life support on August 3.
Dr. Janice Fitzgerald said some of the cases are connected to an advisory issued by Memorial University last week, saying Eastern Health was investigating reports of students experiencing gastrointestinal illness.
The university said Wednesday that test results indicated one student living in residence “may have contracted the E. coli bacteria” and 21 students had reported similar symptoms.
Fitzgerald said it’s too early in the investigation to determine a cause of the outbreak.
Two abstracts attempt to provide guidance to these important questions to reduce the toll of STEC.
FAO and WHO conclude shiga toxin-producing Escherichia coli (STEC) infections are a substantial public health issue worldwide, causing more than 1 million illnesses, 128 deaths and nearly 13 000 Disability-Adjusted Life Years (DALYs) annually.
To appropriately target interventions to prevent STEC infections transmitted through food, it is important to determine the specific types of foods leading to these illnesses.
An analysis of data from STEC foodborne outbreak investigations reported globally, and a systematic review and meta-analysis of case-control studies of sporadic STEC infections published for all dates and locations, were conducted. A total of 957 STEC outbreaks from 27 different countries were included in the analysis.
Overall, outbreak data identified that 16% (95% UI, 2-17%) of outbreaks were attributed to beef, 15% (95% UI, 2-15%) to produce (fruits and vegetables) and 6% (95% UI, 1-6%) to dairy products. The food sources involved in 57% of all outbreaks could not be identified. The attribution proportions were calculated by WHO region and the attribution of specific food commodities varied between geographic regions.
In the European and American sub-regions of the WHO, the primary sources of outbreaks were beef and produce (fruits and vegetables). In contrast, produce (fruits and vegetables) and dairy were identified as the primary sources of STEC outbreaks in the WHO Western Pacific sub-region.
The systematic search of the literature identified useable data from 21 publications of case-control studies of sporadic STEC infections. The results of the meta-analysis identified, overall, beef and meat-unspecified as significant risk factors for STEC infection. Geographic region contributed to significant sources of heterogeneity. Generally, empirical data were particularly sparse for certain regions.
Care must be taken in extrapolating data from these regions to other regions for which there are no data. Nevertheless, results from both approaches are complementary, and support the conclusion of beef products being an important source of STEC infections. Prioritizing interventions for control on beef supply chains may provide the largest return on investment when implementing strategies for STEC control.
Second up, in 2016, we reviewed preventive control measures for secondary transmission of Shiga-toxin producing Escherichia coli (STEC) in humans in European Union (EU)/European Free Trade Association (EEA) countries to inform the revision of the respective Norwegian guidelines which at that time did not accommodate for the varying pathogenic potential of STEC.
We interviewed public health experts from EU/EEA institutes, using a semi-structured questionnaire. We revised the Norwegian guidelines using a risk-based approach informed by the new scientific evidence on risk factors for HUS and the survey results.
All 13 (42%) participating countries tested STEC for Shiga toxin (stx) 1, stx2 and eae (encoding intimin). Five countries differentiated their control measures based on clinical and/or microbiological case characteristics, but only Denmark based their measures on routinely conducted stx subtyping. In all countries, but Norway, clearance was obtained with ⩽3 negative STEC specimens. After this review, Norway revised the STEC guidelines and recommended only follow-up of cases infected with high-virulent STEC (determined by microbiological and clinical information); clearance is obtained with three negative specimens.
Implementation of the revised Norwegian guidelines will lead to a decrease of STEC cases needing follow-up and clearance, and will reduce the burden of unnecessary public health measures and the socioeconomic impact on cases. This review of guidelines could assist other countries in adapting their STEC control measures.
Mapping of control measures to prevent secondary transmission of STEC infections in Europe during 2016 and revision of the national guidelines in Norway
Allie Birchall came down with the severe illness after returning to the UK following a stay at a luxury resort east of the coastal city of Antayla.
Her family were forced to turn off Allie’s life support machine just two weeks after their holiday because of complications caused by the illness.
The family had travelled to Turkey with tour operator Jet2 Holidays on 12 July and said they had concerns about the hygeine of the Turkish resort.
Katie Dawson, Allie’s mother, said her daughter did not start getting ill until five days after getting back to their home in Atherton, Greater Manchester.
According to Ms Dawson, Allie began suffering with stomach cramps, diarrhoea, loss of appetite and lethargy before being admitted to Royal Bolton Hospital on July 30.
The hospital confirmed Allie had contracted Shiga-Toxin producing E.Coli (STEC), which later led to her developing deadly Haemolytic Uraemic Syndrome (HUS) – a life-threatening complication related to the poisoning.
Allie was moved to the Manchester Royal Infirmary and put in an induced coma on August 1.
An MRI scan was carried out, which revealed that she had sustained severe brain trauma and damage. Katie had to make the difficult decision to terminate Allie’s life support following the advice from doctors.
“While nothing will bring her back, we need to know what caused her illness and if anything could have been done to prevent it.
The family have now instructed specialist international serious injury lawyers, Irwin Mitchell, to investigate what happened.
Public Health England is also currently investigating the matter, and an inquest has been opened to examine the circumstances surrounding Allie’s death.
To date, disease doctors have identified 11 cases of E. coli 0157 among Minnesotans who were at the State Fair between Aug. 25 and Sept. 2. All of them fell ill between Aug. 29 and Sept. 6.
Ages of those sickened range from 2 to 43 years old. Six of the cases required the patient to be hospitalized, including one person developing hemolytic uremic syndrome, which the MDH says is a potentially fatal complication.
One person is still in a hospital being treated.
Investigators are working to determine the source of the outbreak, with evidence so far indicating that it most likely began with contact with livestock.
Most of the 11 patients visited the Miracle of Birth exhibit and made physical contact with calves, goats, sheep or piglets, but others suffering from the E. coli strain did not make direct contact with animals, leading the MDH to consider the possibility that those people made contact with contaminated surfaces.
“This serves as a strong reminder to always wash your hands after being around livestock and their enclosures,” the MDH says.
Fortunately, there is “little chance” of ongoing exposure to the strain since the fair has ended.
Erdozain G, Kukanich K, Chapman B, Powell D. 2012. Observation of public health risk behaviours, risk communication and hand hygiene at Kansas and Missouri petting zoos – 2010-2011. Zoonoses Public Health. 2012 Jul 30. doi: 10.1111/j.1863-2378.2012.01531.x.
Observation of public health risk behaviors, risk communication and hand hygiene at Kansas and Missouri petting zoos – 2010-2011Outbreaks of human illness have been linked to visiting settings with animal contact throughout developed countries. This paper details an observational study of hand hygiene tool availability and recommendations; frequency of risky behavior; and, handwashing attempts by visitors in Kansas (9) and Missouri (4), U.S., petting zoos.
Handwashing signs and hand hygiene stations were available at the exit of animal-contact areas in 10/13 and 8/13 petting zoos respectively. Risky behaviors were observed being performed at all petting zoos by at least one visitor. Frequently observed behaviors were: children (10/13 petting zoos) and adults (9/13 petting zoos) touching hands to face within animal-contact areas; animals licking children’s and adults’ hands (7/13 and 4/13 petting zoos, respectively); and children and adults drinking within animal-contact areas (5/13 petting zoos each). Of 574 visitors observed for hand hygiene when exiting animal-contact areas, 37% (n=214) of individuals attempted some type of hand hygiene, with male adults, female adults, and children attempting at similar rates (32%, 40%, and 37% respectively). Visitors were 4.8x more likely to wash their hands when a staff member was present within or at the exit to the animal-contact area (136/231, 59%) than when no staff member was present (78/343, 23%; p<0.001, OR=4.863, 95% C.I.=3.380-6.998). Visitors at zoos with a fence as a partial barrier to human-animal contact were 2.3x more likely to wash their hands (188/460, 40.9%) than visitors allowed to enter the animals’ yard for contact (26/114, 22.8%; p<0.001, OR= 2.339, 95% CI= 1.454-3.763).
Inconsistencies existed in tool availability, signage, and supervision of animal-contact. Risk communication was poor, with few petting zoos outlining risks associated with animal-contact, or providing recommendations for precautions to be taken to reduce these risks.
More than 1.1 million people had already passed through the gates of the San Diego County Fair this summer by the time an E. coli outbreak forced the closure of all animal exhibits and rides.
News that a 2-year-old boy had died after picking up the particularly nasty infection, which was also contracted by three other children with animal contact at the fair, stirred alarm within the community. Many had already roamed the midway, stuffed themselves full of fair food and passed through the venue’s cavernous livestock barns en route to pig races, pony rides and the petting zoo.
Paul Sisson of The San Diego Union Tribune reports hundreds of emails and other documents obtained through Public Records Act requests show that, while the public health team was able to move quickly, more frequent county case reviews, a more modern medical records system and more prompt and accurate responses from families with infected children might have gotten the investigation started days earlier.
The decision to shut down the animal exhibits on June 29, records show, came after four days of a behind-the-scenes scramble by the county’s public health department. With one death already on the books, they decided to notify the public even though testing had not yet confirmed that all four of those first four cases had E. coli infections.
It quickly became clear those initial instincts were accurate. In the following weeks, an additional seven people, plus two more whose infections weren’t confirmed, came forward, including another young boy who nearly died after suffering severe complications that attacked his kidneys.
Records show that zeroing in on the fairgrounds was no simple task. Epidemiologists had to eliminate a broad range of possible locations, from restaurants to a busy daycare center, before they were able to zero in on the fairgrounds.
And there was plenty of other work that had to be done simultaneously. County records show that the department investigated 435 disease cases in June alone. Of those, there were 43 cases of shiga toxin-producing E. coli reported that month, forcing disease detectives to sift out the 11 eventually confirmed to be part of the outbreak.
Determining whether there are connections between cases requires interviews with each subject or their legal guardians. Depending on the type of pathogen involved, it’s a process that often relies on frail human memory to recall the finest possible details of possible exposure routes from foreign travel and foods consumed to places visited and close contact with others.
The investigative process doesn’t get started until the health department is notified, usually after a test result administered in a doctor’s office or hospital comes back positive.
Subjects often aren’t interviewed until weeks after they got infected because many infections have incubation periods measured in days or weeks and it usually takes time before individuals decide to seek medical attention and additional time for medical providers to make a diagnosis.
Often, those charged with reading these particularly fragile tea leaves learn to trust their instincts, and that was certainly the case with the fairgrounds outbreak.
Emails show that the county’s epidemiology team first began to suspect that it might have an outbreak on its hands on June 24, the day that 2-year-old Jedidiah King Cabezuela (right) was admitted to the intensive care unit at Rady Children’s Hospital with severe kidney problems.
While discussing his condition, an epidemiologist noted that the boy had visited the fair before he got sick. And, she said, the county had been notified just before Cabezuela’s death of another boy, this one 9 years old, who tested positive for the type of toxin produced by the E. coli strain causing so much difficulty for Cabezuela.
Though the 2-year-old and 9-year-old hadn’t eaten the same foods at the fair, and the older boy’s parents said he didn’t visit animal areas, the fact that both visited the same location was enough for the epidemiologist to suggest that the department “should at least keep an eye on” the 9-year-old, even though he never got sick enough to need hospitalization.
By Tuesday, June 25, the public health department received the news that Cabezuela died overnight, and that information pushed the team to begin a relentless search for similar shiga toxin-producing E. coli infections.
They quickly found a report of a 13-year-old girl who had a positive toxin test after visiting the fair on June 8. Her parents had told interviewers that she had contact with animals and had eaten fair food afterward without first washing her hands.
Another girl, this one age 11, had also had a positive test but her parents had not returned repeated calls for an interview. It would not become clear that she, too, had visited the fair and had contact with animals until her parents were finally reached on June 28, the same day that the county announced it would close all public animal exhibits.
Then there was the 9-year-old boy mentioned in that prescient June 24 email. His parents initially said that he had no animal contact at the fair, but in subsequent interviews those parents remembered that, yes, their son did visit the livestock barn when the family visited on June 13.
With three, then four cases all reporting food consumption and animal contact at the fairgrounds, food inspectors descended on five different food vendors who sold items that the kids reported eating and found no traces of E. coli contamination.
Food poisoning ruled out, officials concluded that the E. coli exposure was most likely down to animals and, with the cooperation of the fair board, shut down all public access to animal exhibits and rides on June 29. Testing never did pinpoint the exact source of contamination, though the fair’s petting zoo and pony rides were ruled out.
Once public health nurses do their phone interviews and build up as clear a picture as they can of the circumstances surrounding each individual case, epidemiologists can begin looking for patterns, keeping an eye out for clusters of patients in specific geographic areas or with other commonalities such as foreign travel or consumption of tainted food.
A timeline of the E. coli outbreak at the San Diego County Fair
May 31– San Diego County Fair opens
June 8 –11-year-old and 13-year-old girls visit fair
June 10 –13-year-old becomes ill
June 12 –11-year-old becomes ill after a second fair visit
June 13 – 9-year-old boy visits fair
June 15 – 2-year-old Jedidiah Cabezuela visits fair
June 16 – 9-year-old becomes ill
June 18 – Investigator call parents of 11-year-old, get no reply
June 19 – 13-year-old reports visiting animal areas at fair; Jedidiah becomes ill; county holds weekly analysis meeting
June 20 – Jedidiah admitted to Rady Children’s Hospital
June 21 – 4-year-old and 38-year-old who later test positive for E. coli infections visit fair
June 22 – Jedidiah diagnosed with severe E. coli infection; 6-year-old Ryan
Sadrabadi, 2-year-old Cristiano Lopez and his mother, Nicole Lopez, and another 2-year-old girl, visit the fair
June 23 – Family confirms Jedidiah visited fair’s animal exhibits; one-year-old girl later confirmed to have E. coli infection visits the fair
June 24 – Jedidiah dies from kidney failure; 9-year-old’s fair attendance confirmed, animal contact denied; County epidemiologist raises red flag about possible case cluster at fair; Nicole Lopez becomes ill, treated at Kaiser La Mesa
June 25 – County learns of Jedidiah’s death, begins exploring fair connections in depth
June 26 –Ryan, 2-year-old girl and 1-year-old become ill
June 28 – Family of 9-year-old revises statement, confirms visiting livestock barn; Family of 11-year-old confirms she visited sheep exhibit at fair; County announces E. coli cluster at Del Mar Fairgrounds; County inspects five food booths visited by first four cases, no E. coli found; Cristiano becomes ill
June 29 – County inspects all 160 food booths at fair, finds no E. coli contamination; All animal areas at the fair are closed; four-year-old becomes ill
June 30 – Ryan becomes ill diagnosed with E. coli infection
July 1 – 6-year-old’s case reported to county
July 2 – Cristiano admitted to Kaiser Permanente San Diego Medical Center with worsening symptoms, diagnosed with E. Coli infection
July 3 – 2-year-old girl and 4-year-old’s cases reported to county
July 4 – Fair closes with an attendance that exceeds 1.5 million; Cristiano’s infection reported to county; Cristiano transferred to Rady Children’s Hospital, undergoes dialysis for hemolytic uremic syndrome that attacks his kidneys
July 6 – 38-year-old becomes ill
July 9 – 38-year-old’s infection reported to county
July 10 – 30-year-old’s and 1-year-old’s infections reported to county
July 29 – Three families file claims against fair board, alleging they weren’t properly warned of E. coli risk
July 31 – Environmental and animal testing fail to reveal a clear source of outbreak, but exposure in fair’s livestock barn deemed “likely”
Best practices for planning events encouraging human-animal interactions
Zoonoses and Public Health
G. Erdozain , K. KuKanich , B. Chapman and D. Powell
Educational events encouraging human–animal interaction include the risk of zoonotic disease transmission. It is estimated that 14% of all disease in the US caused by Campylobacter spp., Cryptosporidium spp., Shiga toxin-producing Escherichia coli (STEC) O157, non-O157 STECs, Listeria monocytogenes, nontyphoidal Salmonella enterica and Yersinia enterocolitica were attributable to animal contact. This article reviews best practices for organizing events where human–animal interactions are encouraged, with the objective of lowering the risk of zoonotic disease transmission.
In the spring of 2018, an E. coli O157 outbreak linked to romaine lettuce grown in the Yuma, Arizona area resulted in 210 reported illnesses from 36 states, 96 hospitalizations, 27 cases of hemolytic uremic syndrome (HUS) and five deaths.
The U.S. Food and Drug Administration has launched a new initiative with support from the Arizona Department of Agriculture, and in conjunction with the University of Arizona Cooperative Extension, the Wellton-Mohawk Irrigation and Drainage District (WMIDD), and members of the Yuma area leafy greens industry to better understand the ecology of human pathogens in the environment in the Yuma agricultural region. This initiative will be a multi-year study which will focus on how these pathogens survive, move and possibly contaminate produce prior to harvest.
While the FDA, the Arizona Department of Agriculture and other state partners conducted an environmental assessment from June through August 2018 that narrowed the scope of the outbreak, the specific origin, the environmental distribution and the potential reservoirs of the outbreak strain remain unknown.
Between 2009 and 2017, FDA and partners at CDC identified 28 foodborne STEC outbreaks with known or suspected links to leafy greens. Like a lot of fresh produce, leafy greens are often eaten raw without a kill-step, such as cooking, that could eliminate pathogens that may be present.
Sounds like Yuma growers could use a Box of Rain. Or maybe more knowledge of the microbial ripple effect. May death be groovy for you, long-time Grateful Dead collaborator and lyricist Robert Hunter, who passed on Tuesday, aged 78.