From planting to distribution, fresh produce can be contaminated by humans, water, animals, soil, equipment, and the environment. Produce growers play an essential role in managing and minimizing on-farm food safety risks. Because of an increase in public awareness about produce safety, farmer food safety education has become an important research and extension topic. This review article summarizes findings by researchers who have evaluated produce growers’ food safety knowledge and attitudes and the effectiveness of food safety educational programs for growers.
A search of on-line databases, journal archives, conference abstracts, and reference lists of relevant studies was conducted to locate peer-reviewed articles on produce growers’ food safety knowledge and behavioral changes. Study selection criteria included publications in English, publication between 2000 and 2019, and a focus on one of six topics: handling of agricultural water, soil amendments, domesticated animal and wildlife management, worker health and hygiene, food safety plans and record-keeping, and cleaning and sanitation. Forty-three published articles were included in the analysis. Handling of agricultural water and soil amendments were the two topics least understood by growers, whereas worker health and hygiene were the best understood. Food safety educational interventions were evaluated in 13 studies, and most studies used in-person workshops and self-reported pre- and postintervention knowledge assessments. Most reported increased knowledge, some reported improved attitudes and perceived behavioral control, and only four reported behavioral changes. Because of small sample sizes, many studies did not include a statistical analysis of the differences between pre- and postintervention survey results. This review article provides insights and guidance for the development of food safety education for produce growers.
Produce growers’ on-farm food safety education: A review
Journal of Food Protection
HAN CHEN ; AMANDA J. KINCHLA ; NICOLE RICHARD ; ANGELA SHAW ; YAOHUA FENG
A new report into Australia’s 2018 strawberry tampering crisis, which caused catastrophic economic damage to the industry, has found food-tracing protocols need to be strengthened.
Lucy Stone of The Sydney Morning Herald reports the report also found that food safety expertise in the horticulture industry was “variable” due to there being many small businesses, with no regulatory or industry oversight particularly for strawberry farmers (uh, I’m right here).
The “fragmented nature” of the sector also complicated matters with no regulation tracking strawberry farm locations during the crisis, and the use of seasonal or contract pickers muddying traceability.
Food Standards Australia New Zealand (FSANZ) was commissioned by Health Minister Greg Hunt to review the response to the strawberry contamination crisis, which began on September 9 when a man swallowed a needle hidden inside a strawberry.
Within days more reports had been made to Queensland Health and Queensland Police of similar incidents, sparking copycat actions of needles being hidden in fruit across Australia and New Zealand.
The crisis saw strawberry production nationally grind to a halt, with Queensland growers dumping thousands of tonnes of fruit that could not be sold.
Is there a better approach to both protect and enhance consumer confidence in the wake of an outbreak, tampering, or even allegations of such?
On June 12, 1996, Dr. Richard Schabas, chief medical officer of Ontario (that’s a province in Canada), issued a public health advisory on the presumed link between consumption of California strawberries and an outbreak of diarrheal illness among some 40 people in the Metro Toronto area. The announcement followed a similar statement from the Department of Health and Human Services in Houston, Texas, which was investigating a cluster of 18 cases of cyclospora illness among oil executives.
Turns out it was Guatemalan raspberries, not strawberries, and no one was happy.
The initial, and subsequent, links between cyclospora and strawberries or raspberries in 1996 was based on epidemiology, a statistical association between consumption of a particular food and the onset of disease.
The Toronto outbreak was first identified because some 35 guests attending a May 11, 1996 wedding reception developed the same severe, intestinal illness, seven to 10 days after the wedding, and subsequently tested positive for cyclospora. Based on interviews with those stricken, health authorities in Toronto and Texas concluded that California strawberries were the most likely source. However, attempts to remember exactly what one ate two weeks earlier is an extremely difficult task; and larger foods, like strawberries, are recalled more frequently than smaller foods, like raspberries.
By July 18, 1996, the U.S. Centers for Disease Control declared that raspberries from Guatemala — which had been sprayed with pesticides mixed with water that could have been contaminated with sewage containing cyclospora — were the likely source of the cyclospora outbreak, which ultimately sickened about 1,000 people across North America. Guatemalan health authorities and producers vigorously refuted the charges. The California Strawberry Commission estimated it lost $15-20 million in reduced strawberry sales.
The California strawberry growers decided the best way to minimize the effects of an outbreak – real or alleged – was to make sure all their growers knew some food safety basics and there was some verification mechanism. The next time someone said, “I got sick and it was your strawberries,” the growers could at least say, “We don’t think it was us, and here’s everything we do to produce the safest product we can.”
There is a lack – a disturbing lack – of on-farm food safety inspection; farmers need to be more aware of the potential for contamination from microbes (from listeria in rockmelon, for example) as well as sabotage.
There is an equally large lack of information to consumers where they buy their produce. What do Australian grocery shoppers know of the food safety regulations applied to the produce sold in their most popular stores? Do such regulations exist? Who can they ask to find the answers?
The Sydney Morning Herald also notes that in the report published on Friday, FSANZ made several recommendations to prevent similar crises in the future, including greater regulation for the industry.
The lack of a peak soft fruits regulatory body left the small Queensland Strawberry Growers Association “inundated with calls”, while national horticulture body Growcom later helping manage communication.
The crisis prompted Prime Minister Scott Morrison to announce legislation to extend the jail time for anyone convicted of food tampering to 15 years.
Food Standards Australia New Zealand made seven recommendations in its final report, including a recommendation that all jurisdictions review food incident response protocols.
A central agency should be engaged to manage national communication in future food tampering incidents, and communication between regulators, health departments and police should be reviewed, the organisation found.
Triggers for “activation and management of intentional contamination of food” under the National Food Incident Response Protocol (NFIRP) should also be reviewed.
This recommendation was despite the NFIRP not being activated during the strawberry contamination issue. The protocol is a national incident response that can be activated by any agency to manage food incidents.
“Due to the unique criminal nature of this case and associated investigation, the protocol was not triggered,” the report said.
The horticulture sector also needs a representative body to “support crisis preparedness and response”, and traceability measures to track food through the sector needed greater work.
“Government and industry should work together to map the current state of play and identify options and tools for enhancing traceability,” the FSANZ report recommended.
A single national website for food tampering should be set up to give the public clear information, the report found.
The report found greater regulation of the horticulture sector was needed and cited the complexity of small farm and distribution operations as making the investigation difficult.
A suggestion that strawberry farms should be fitted with metal detectors also raised concerns about cost and practicality, while tamper-proof packaging risked shortening shelf life, and criticisms about increased use of plastic packaging.
For 20 years, I have been advising fruit and vegetable growers there are risks: Own them: Say what you do, do what you say, and prove it. The best producers or manufacturers can do is diligently manage and mitigate risks and be able to prove such diligence in the court of public opinion; and they’ll do it before the next outbreak.
Grower Carol Metcalf said the rows of rotting melons were the result of the listeria outbreak on a rockmelon farm more than 3,500 kilometres away in New South Wales.
Under a new plan released this week, all rockmelon farms in Australia will be inspected and work will be undertaken on each individual farm to ensure that the highest standards are implemented and maintained.
At the time of the outbreak on February this year, the NSW Food Authority speculated that the most likely cause of the listeria outbreak was contaminated soil possibly not being properly washed off the skin of the fruit.
In addition it was thought that a weather event may have increased the listeria bacteria on the product.
But the formal investigation into the cause of the outbreak has not been completed by the NSW Food Authority and therefore the official report on the cause has still not been released.
What is planned is visits to all Australian rockmelon growers and packing sheds to review and audit current practice and critical control points and provide one-on-one food safety consultations with growers, managers and key farm staff.
The development of a melon food safety Best-Practice Guide, was informed by the findings from consultations, feedback from retailers and other key stakeholder groups.
The development of a ‘toolbox’ for grower use including risk assessment templates, training guides, food safety posters and record sheets to support food safety programs — this will be housed on the Australian Melon Association website.
Regional roadshows in key growing regions will highlight the availability and contents of the toolbox and Best Practice Guide.
A helpdesk to provide technical support to growers, packers and other stakeholders will also be developed.
Australian Melon Association industry development manager Dianne Fullelove said the new initiatives would ensure that every rockmelon grower in Australia had the highest level of food safety possible.
“NSW DPI will lead the project and the key is that they will visit every farm and work with every grower to fix any problems or issues.
“We want to make food safety as good as it can be,” Ms Fullelove said.
“This new initiative will make that reputation even stronger and give our growers sure-fire tools to support our product integrity for decades to come.
“This move will put us ahead of the game.”
Food safety isn’t a game, not when your product contributes to the death of seven people and one miscarriage.
Why are melon growers relying on government to visit farms (oh, right, money).
They should hire their own people to be out front on any food safety issue; government is the last source to rely on. And don’t act like this is something new: There have been plenty of outbreaks of Listeria and Salmonella on rockmelon over the years.
(A table of rockmelon-related outbreaks is available here.)
Some basic questions that have yet to be answered:
was the farm prone to flooding and near any livestock operations;
what soil amendments, like manure, were used;
after harvest were the rockmelons placed in a dump tank;
was the water in the dump tank regularly monitored for chlorine levels;
did a proper handwashing program exist at the packing shed;
were conveyor belts cleaned and tested;
did condensation form on the ceiling of the packing shed;
were transportation vehicles properly cooled and monitored;
was the Listeria in whole cantaloupe or pre-cut; and,
was the rockmelon stored at proper temperatures at retail?
Stop waiting for change to happen and take charge, without relying on government: Your growers are still losing money.
In sentencing me to jail in 1982, the judge said I had a memory of convenience.
I had said I had a memory of not much.
Spinach and lettuce growers seem to have a memory of not much, given the produce industry’s revisions to the 2006 E. coli O157:H7 outbreak in spinach that killed four and sickened 200.
In October, 1996, a 16-month-old Denver girl drank Smoothie juice manufactured by Odwalla Inc. of Half Moon Bay, California. She died several weeks later; 64 others became ill in several western U.S. states and British Columbia after drinking the same juices, which contained unpasteurized apple cider — and E. coli O157:H7. Investigators believed that some of the apples used to make the cider might have been insufficiently washed after falling to the ground and coming into contact with deer feces.
In the decade between these two watershed outbreaks, almost 500 outbreaks of foodborne illness involving fresh produce were documented, publicized and led to some changes within the industry, yet what author Malcolm Gladwell would call a tipping point — “a point at which a slow gradual change becomes irreversible and then proceeds with gathering pace” (http://en.wikipedia.org/wiki/Tipping_Point) — in public awareness about produce-associated risks did not happen until the spinach E. coli O157:H7 outbreak in the fall of 2006. At what point did sufficient evidence exist to compel the fresh produce industry to embrace the kind of change the sector has heralded since 2007? And at what point will future evidence be deemed sufficient to initiate change within an industry?
In 1996, following extensive public and political discussions about microbial food safety in meat, the focus shifted to fresh fruits and vegetables, following an outbreak of Cyclospora cayetanesis ultimately linked to Guatemalan raspberries that sickened 1,465 in 21 U.S. states and two Canadian provinces (U.S. Centers for Disease Control and Prevention, 1997), and subsequently Odwalla. That same year, Beuchat (1996) published a review on pathogenic microorganisms in fresh fruits and vegetables and identified numerous pathways of contamination.
E. coli O157:H7
E. coli O157:H7
E. coli O157:H7
E. coli O153:H48
E. coli O153:H47
E. coli O157:H7
E. coli O153:H46
E. coli O157:H10
E. coli O153:H49
Table 1. Outbreaks of foodborne illness related to leafy greens, 1992-1996.
By 1997, researchers at CDC were stating that pathogens could contaminate at any point along the fresh produce food chain — at the farm, processing plant, transportation vehicle, retail store or foodservice operation and the home — and that by understanding where potential problems existed, it was possible to develop strategies to reduce risks of contamination. Researchers also reported that the use of pathogen-free water for washing would minimize risk of contamination.
E. coli O157:H9
E. coli O111:H8
E. coli O157:H11
E. coli O157:H7
E. coli O157:H7
E. coli O157:H7
Table 2. 1999 U.S. outbreaks of STEC linked to leafy greens
Yet it would take a decade and some 29 leafy green-related outbreaks before spinach in 2006 became a tipping point.
E. coli O157:H7
E. coli O157:H7
E. coli O157:H8
E. coli O157:H7
E. coli O157:H7
Table 3: Leafy green outbreaks of STEC, 2000 — 2002.
What was absent in this decade of outbreaks, letters from regulators, plans from industry associations and media accounts, was verification that farmers and others in the farm-to-fork food safety system were seriously internalizing the messages about risk, the numbers of sick people, and translating such information into front-line food safety behavioral change.
E. coli O157:H7
E. coli O157:H7
E. coli O157:H7
E. coli O157:H7
Table 4: Leafy green STEC outbreaks, 2003 — 2005.
So why was spinach in 2006 the tipping point?
It shouldn’t have been.
But it lets industry apologists say, how the hell could we known?
Tom Karst of The Packer reports the crisis of confidence in the status quo of produce safety practices arrived with a thud a little more than 10 years ago.
Beginning Sept. 14 and continuing until Sept. 20, 2006, the U.S. Food and Drug Administration issued daily news releases that flatly advised consumers “not to eat fresh spinach or fresh spinach-containing products until further notice.”
The agency had never before issued such a broad warning about a commodity, said Robert Brackett, who in 2006 was director of FDA’s Center for Food Safety and Applied Nutritions. Brackett is now vice president and director of the Institute for Food Safety and Health at the Illinois Institute of Technology,
“In this particular case all we knew (was) that it was bagged leafy spinach, but we had no idea whose it was or where it was coming from,” he said in December of this year.
“It was a very scary couple of days because we had all of these serious cases of hemolytic-uremic syndrome popping up and people getting sick, and it was so widespread across the country.”
The Centers for Disease Control and Prevention reported about half of those who were ill were hospitalized during the 2006 spinach E. coli outbreak.
“It was shocking how little confidence that FDA and consumers had in the produce industry at that moment,” said David Gombas, retired senior vice president of food safety and technology for the Washington, D.C.-based United Fresh Produce Association.
Given the history of outbreaks, the only thing shocking was that the industry continued to expect blind faith.
“For FDA to say ‘Don’t eat any spinach,’ they blamed an entire commodity, and it became very clear to the produce industry at that moment they had to do something to restore public confidence and FDA confidence in the safety of fresh produce,” Gombas said Nov. 30.
“One of the things that was very different and had the greatest impact was the consumer advisory against spinach — period — regardless of where it came from,” said Trevor Suslow, extension research specialist and director of the University of California-Davis Postharvest Technology Center.
The stark warning — immediately followed by steeply falling retail spinach sales — was issued in the midst of a multistate E. coli foodborne illness outbreak eventually linked to Dole brand baby spinach.
The product was processed, packed and shipped by Natural Selection Foods of San Juan Bautista, Calif., which markets the Earthbound Farm brand.
U.S. Department of Agriculture data shows that California’s spinach shipments plummeted from 258,774 cartons in August 2006 to 138,278 cartons in September, a drop of nearly 50%.
Shipping point prices for spinach on the California coast dropped from $8.45-10.45 per carton on Sept. 14 — the day that FDA first issued its advice to avoid for consumers to avoid spinach — to $4.85-6.15 per carton on Sept. 15.
No market was reported by the USDA for the rest of September because supplies were insufficient to quote.
The final update on the 2006 spinach outbreak was published by the CDC in October. By March 2007, the FDA issued its own final report about its investigation on the cause of the outbreak.
The CDC said in October 2006 that 199 persons infected with the outbreak strain of E. coli O157:H7 were reported to CDC from 26 states. Later, the tally of those sickened was raised to 205.
Gombas said the FDA warning in mid-September caused leafy green sales to crash, not fully recovering for nearly a decade.
“There were outbreaks before that, but none of them were as devastating to industry or public confidence as that one.”
The FDA and the California Department of Public Health issued a 51-page report on the extensive investigation into the causes of an E. coli O157:H7 outbreak associated with the contaminated Dole brand baby spinach.
The report said investigators identified the environmental risk factors and the areas that were most likely involved in the outbreak. However, they were unable to definitely determine the source of the contamination.
The investigation explored the source of the spinach in 13 bags containing E. coli O157:H7 isolates that had been collected nationwide from sick customers, according to a summary of the report.
Using the product codes on the bags, and employing DNA fingerprinting on the bacteria from the bags, the investigators were able to match environmental samples of E. coli O157:H7 from one field to the strain that had caused the outbreak, according to the report.
The report said E. coli O157:H7 isolates located on the Paicines Ranch in San Benito had a (pulsed-field gel electrophoresis) pattern indistinguishable from the outbreak strain. The report said the pattern was identified in river water, cattle feces and wild pig feces on the Paicines Ranch, the closest of which was just under one mile from the spinach field.
According to investigators, the sources of the potential environmental risk factors for E.coli contamination at or near the field included the presence of wild pigs and the proximity of irrigation wells and waterways exposed to feces from cattle and wildlife.
From 1995 to 2006, researchers had linked nine outbreaks of E. coli O157:H7 infections to, or near, the Salinas Valley region. But the 2006 spinach outbreak was different.
There were guidelines for growers in 2006, but not a way to make sure growers were following them, said Joe Pezzini, CEO of Ocean Mist Farms, Castroville, Calif.
Ann Hui of the Globe and Mail reports that a few years ago, federal food inspectors were walking around the warehouses of the Ontario Food Terminal in Toronto – the nerve centre where much of the province’s fresh produce is bought, re-packaged and sold – when they noticed something unusual.
In the “farmer’s market” area, where only Ontario-grown produce is meant to be sold, the inspectors saw large cartons of greenhouse peppers with conflicting labels. The outside of the boxes had “Product of Canada” stickers, next to visible signs of damage on the cardboard – bits of paper and glue, as if another sticker had been peeled off. And stickers on the inside of the box read “Product of Mexico.”
That discovery in January, 2012, led the Canadian Food Inspection Agency into a three-year investigation of the company behind the peppers, Mucci Farms – the largest such probe in the agency’s history.
After executing three search warrants at the company’s headquarters in Kingsville, Ont., and poring over its computer records and internal e-mails, CFIA investigators pieced together evidence that, between late 2011 and early 2013, Mucci had been selling imported products as Canadian – putting hundreds of shipments of mislabelled produce worth more than $1.4-million onto Ontario grocery store shelves.
In one e-mail described in a court document and obtained by The Globe and Mail, one of the company’s directors, Danny Mucci, responded to a message from an employee about a shortage of Canadian mini cucumbers by telling the worker: “you know what to do to fill…it’s only 30 cases.”
Mucci International Marketing Inc., Mucci Pac Ltd. and two of its directors (Mr. Mucci and Joseph Spano) pleaded guilty in June of this year to eight regulatory offences – including one count against the company for selling food in a “false, misleading or deceptive” manner – and were fined $1.5-million.
Mucci’s lawyer, Patrick Ducharme, said in an interview that the mislabelling was not intentional, and that, given the volume of Mucci’s 1,200-employee operation, the transactions made up “a very small part of what they do.” He also emphasized that they pleaded guilty to regulatory offences, not criminal ones. Criminal charges against Mucci International and Mucci Pac and the two directors of defrauding the public, and defrauding Costco, Loblaw and Sobeys – to whom Mucci sold the produce – were withdrawn.
The case sent shockwaves through the country’s agriculture industry, and the Ontario Greenhouse Vegetable Growers called it a “unique” precedent. “My hope is that it’s an isolated case,” the marketing board’s manager, Rick Seguin, said in an interview.
I helped – or did – set up the OGVG on-farm food safety program way back when OFFS wasn’t cool – about 1998.
We got a couple of papers out of it, along with reams of anectodes and observations and every time I’ve blogged about them, the new types at OGVG have threatened to sue (that’s a pic, upper left, of my 14-monty-old grandon #2, Emerson, instead of tomatoes; sue that).
I’m used to that.
And since I’m just a lowly former academic, the legal types tell me, you can’t afford it.
For years, experts have been sounding the alarm on mislabelling and food fraud. Increasingly, they say, criminal organizations around the world are targeting the food system, intercepting supply chains and deliberately misrepresenting or adulterating products – and costing the food industry between $10-billion and $15-billion (U.S.) each year, according to the U.S.-based Grocery Manufacturers Association.
And, according to conversations with experts in the Canadian food industry, scientists and regulators, the problem is widespread within our own borders.
But even the CFIA does not seem to know just how widespread it is. Individual cases provide an incomplete picture. And the 74 cases of non-compliance with labelling laws from the past year published on the CFIA website – a number the agency say has held steady over the past five years – present only a portion of incidents where the agency has found companies breaking the rules. It includes only the cases in which the products were actually seized and detained or disposed of, but also includes technical infractions, like language or font size on packaging.
When asked how prevalent the problem is in Canada, the agency cited U.S. data that show fraud affects about 10 per cent of all food products globally. It also acknowledged it has not yet conducted a widespread survey of its own to understand its full impact within Canada.
In his years as a lawyer representing companies in intellectual property and anti-counterfeiting cases in Canada, Lorne Lipkus has seen cases of food fraud ranging from counterfeit basmati rice (knockoffs of a high-end brand) to fake ginseng.
“You’d think: ‘How expensive is it to grow a bag of rice,’” he said. “But if someone’s making something and making a profit out of it, somebody’s counterfeiting it. … Everything we do in Canada is reactive. We have very poor laws, compared to other countries. And we haven’t had any government involved in the longest time – I’m talking decades – willing to provide the resources to law enforcement to do anything about counterfeiting.”
In EU countries, border officials have the authority to seize and destroy goods they believe are counterfeit. In Canada, customs officials can detain a product, but it is then incumbent on the complainant to undertake court action and to pay for the goods to remain in detention until the case is heard – which can cost in the tens of thousands of dollars.
Most alarming, he said, is that the scope of the problem is not understood because no agency is specifically looking for fraud.
On the issue of mislabelling, experts also point to policy initiatives abroad – such as a U.S. proposal to require companies to have food fraud prevention programs – as evidence others seem to take the issue more seriously.
Although the CFIA has not conducted a full survey of the issue in Canada, James Crawford, acting associate vice-president of operations with the federal agency, said CFIA receives about 40 complaints a year about possible food misrepresentation.
In an interview, Mr. Crawford said the agency takes food fraud seriously. He also said Canadians are generally safe from adulterated food – pointing to a Conference Board of Canada study in 2014 that ranked the country’s food system as the safest of 17 OECD countries surveyed.
That was a bullshit survey with criteria based on nothing.
On fraud, he said, “we’re proactive and reactive.”
He said CFIA staff conduct regular inspections of imported and domestic food – including daily inspections at meat processing plants. Still, he was not able to say what percentage of products undergoes such scrutiny for labelling.
“We can’t inspect every … import or domestically produced food in Canada. It’s impossible. That’s why we have a risk-based plan. And it allows us to focus on where we think the high risks are.” Some of the things the agency takes into account in prioritizing inspections include food type and likelihood for illness, and each company’s track record of compliance.
Even countries with the most aggressive approaches faced the reality that food fraud is not easily confined by borders.
In Canada, much of the action on the issue has been industry-led. Large retailers in Canada like Loblaw or Costco have programs to safeguard against adulterations, requiring suppliers to subscribe to standardized food safety programs, and undergo annual audits.
As for Mucci, it is on a three-year probation during which CFIA inspectors will have free access to its premises and computer records. Mr. Ducharme says the company is doing everything it can to ensure accuracy of its labelling, including appointing a compliance officer and reviewing all of its processes.
He believes the CFIA targeted Mucci in part to set an example. “I don’t think it’s insignificant that the place that was targeted for the big investigation was the biggest in the industry,” he said. “They know Mucci’s the biggest. The best.”
The research began last year after the U.S. Food and Drug Administration released a proposed produce safety rule that would limit the amount of generic E. coli bacteria that can be present in irrigation water.
This year’s trial is much larger and researchers expect it will confirm last year’s findings, which showed bulb onions pose no risk of E. coli contamination, regardless of how they are irrigated and regardless of the water quality.
Researchers even enriched some of the water with extremely high levels of generic E. coli by using runoff water from a pasture. Still, there was no trace of bacteria when the onions were ready for packing.
“By the time we packed them out, the numbers were all zero,” said Clint Shock, director of the Malheur experiment station.
There were traces of E. coli present on the outside of some onion bulbs when they were pulled out of the soil and left on the ground to dry. But after they were cured in the field — all bulb onions in this area go through that process — and ready for packing, no E. coli was present on any of the onions.
“The results of last year showed that the bacteria died off really rapidly after they were lifted, and cured in the field,” Shock said. “And we didn’t have any generic E. coli at all on any of the onions when we packed them out.”
E. coli levels for soils and onions were recorded during growing, harvesting and processing conditions. At no time was E. coli ever detected inside of any of the onions.
The work, led by Dr. Renata Ivanek and her lab in the Department of Veterinary Integrative Biosciences (VIBS) at the Texas A&M College of Veterinary Medicine & Biomedical Sciences (CVM), was a collaborative effort between researchers at Texas A&M University, Colorado State University, Texas Tech University, and Texas A&M AgriLife Extension Service.
In this study, the research team cross-referenced environmental data with information from participating farms in multiple test areas. Then, the team determined how three groups of factors—farm management, location, and weather—affect spinach contamination with E. coli. The team studied spinach samples from 12 farms in Colorado and Texas and compared variables including the local temperature, precipitation, wind speed, soil characteristics, proximity to roads and water bodies, and such farm management practices as the farm workers’ hygiene and manure application practices.
Overall, the study found that farm management, location, and weather factors should be considered jointly in developing agricultural methods and interventions that reduce the threat of E. coli contamination at the pre-harvest level. The odds of spinach contamination decreased to approximately 1 in 17 with implementation of good hygiene practices for farm workers, but they increased to approximately 4 in 1 for every millimeter increase in the average amount of rain in the month before harvest. Furthermore, applying manure fertilizer on the field increased the odds of contamination to approximately 52 in 1.
“Hygiene practices and fertilizers used are relatively easy to change,” Ivanek said. “The challenge, however, will be to use the information about how rainfall affects produce safety into an intervention, or plan, that growers could implement on a daily basis.”
In September 2013, a national increase in cases of verotoxigenic E. coli O157 phage type 2 VT2 was observed in England. Between 30 August and 19 September, 19 cases (14 in England, four in Wales and one in Scotland) were reported sharing the same distinct Multi Locus Variable Number Tandem Repeat Analysis (MLVA) pattern (and single locus variants), not previously seen in the UK. Onset dates ranged from 17 to 29 August and the cases had an unusual demography for VTEC cases: they were predominantly female with a median age of 64 years. Seven cases were hospitalized, although no deaths or cases of hemolytic uremic syndrome (HUS) were reported. Interviews with patients and the use of detailed food questionnaires revealed the link to the consumption of pre-packaged watercress purchased from a particular supermarket chain. This led to the prompt voluntary withdrawal and recall of watercress products by the retailer.
Despite trace-back investigations, microbiological testing of watercress and environmental sampling at farms, the source of contamination of the watercress remains unclear. Two additional cases with an identical MLVA profile were retrospectively identified with onset dates in February 2013. One had consumed watercress and one pre-packaged salad, both from retailers representing a different supply chain, suggesting that the contamination is unlikely to have occurred at the farms. Following restocking of watercress at the supermarket chain, one additional case was reported with an onset date of 21 October 2013. The case reported consuming bagged mixed salad containing watercress from that supermarket. No further cases of the outbreak profile have been reported.
During outbreak investigations, a second, smaller outbreak of six cases of VTEC O157 PT 2 VT2 with a different MLVA profile was identified: two cases reported consuming watercress from the implicated retailer prior to the recall, one consumed watercress prior to the recall but with no detail on where it was purchased, and one consumed mixed salad from the retailer during the period that watercress was withdrawn from sale. Two further cases with onsets of 1 October 2013 were members of a family who had consumed watercress as part of a meal at a pub. Local trace-back confirmed that the pub purchased unwashed watercress from the same supplier as was involved in the first outbreak.
During sampling of the farms supplying watercress, VTEC O157 PT 2 VT2 identical on typing to isolates from the second outbreak was isolated from one of the watercress beds. Environmental investigations revealed that this watercress bed was in close proximity to an adjacent field containing cattle – the primary reservoir for VTEC. It seems likely that the cause of this second cluster of cases was transfer of VTEC from the field to the watercress bed either from wildlife entering the watercress farm or run-off water.
There was this time, we thought we’d killed Chapman.
Ben and I went along with Uncle Denton to the Canadian Horticulture Council meeting in Montreal in Feb. 2003. I had chaired a national committee on on-farm food safety program implementation – and the advice was completely ignored – Chapman and I had done years of groundwork with Denton and the Ontario Greenhouse Vegetable Growers, and we agreed to share a room at the annual meeting to cut down on expenses.
There was a couple of receptions and I still remember Ben and I asking Uncle Denton for drink tickets. We then retired to a hotel lounge and I knew trouble was ahead when Chapman asked for a cigarette.
As you journey through life you meet the occasional person who makes a real difference. Dr. Douglas Powell is one of those – to say the least.
Doug called me recently to talk about the early years. He was new in the On Farm Food Safety business when I was working with the Ontario Greenhouse vegetable group. Doug was at the University of Guelph and I would talk to him about the phone call I didn’t want to get. This would be the imaginary call from a senior’s residence wondering why all the occupants were very sick after consuming a fresh salad, and if the cause may have been the greenhouse tomatoes. I never got that call—thank God–but I wanted to be ready. And that readiness included a strong response indicating we had an On Farm Food Safety program and proof we were capable of tracing our greenhouse product. We’ve seen several incidences in the past few years with certain fresh veggies and berries that almost ruined the industry and certainly crippled those markets for a year or so.
From the University of Guelph and the beginning of the On Farm Food Safety program, Doug has moved to Kansas State University where he is associate professor of food safety. He is still very much in the industry – just relocated to a different university — and still writing newsletters, hence the reputation of “the guru” of On Farm Food Safety.
Doug has remained a good friend over all these years. We developed a bond as we developed an On Farm Food Safety program for greenhouse vegetables and more. Doug’s philosophy was to keep it simple. He could relate to growers, and had an uncanny ability to make the complicated science of bacterial contamination simple and understandable. Early on, he received a little help from Dr. Gord Surgeoner. These were the seeds of the On Farm Food Safety program in Canada, spreading from Ontario Greenhouse to CHC and to most vegetable growers across Canada.
I can still see Doug in an old T-shirt and jeans, holes in both, and running shoes–that was his fashion statement. Of course, his description of toilet paper “slippage” resulting in fecal contamination on your finger was priceless, but his crude description helped to break down the mystery of bacterial contamination by food handlers with dirty hands. Seems to me I got a T-shirt from Doug with “Don’t Eat Poop” written on the front. Doug continues to be a great communicator, a fair goalie, poor at politics but great at On Farm Food Safety and raising little girls.
Thanks, Doug. I am proud to say I knew you back when.