Berries breaking my heart: Risk ranking in fresh produce in Denmark

My friend Miriam Meister writes that the risk of getting a foodborne infection from fresh fruit and vegetables in Denmark is highest from consumption of berries, lettuce, sprouts, tomato and melon. This is the finding of a risk ranking performed by the National Food Institute, Technical University of Denmark for the Danish Veterinary and Food Administration. The ranking can be used to prioritise initiatives aimed at strengthening food safety.

Frosne-hindbær-700x350Danes eat more fruit and vegetables then they used to. Consumption has increased from 1995-2013 by 30%. Danish consumers also have greater access to fresh produce from all over the world. At the same time fresh fruit and vegetables have increasingly been the cause of foodborne infections – not only in Denmark but in the entire industrialised world. As a consequence of the increased global trade there is a risk that disease-causing microorganisms, which were only rarely or never found in Denmark, are being introduced onto the Danish market through imported goods.

This is the reason that the National Food Institute has evaluated the risk from microorganisms in ready-to-eat fresh fruit and vegetables on the Danish market. A list has been drawn up of combinations of products and disease-causing microorganisms, which pose the greatest risk of disease to Danish consumers. A total of 30 different combinations are included.

The ranking is based on an overall assessment of the risk posed by each of the 30 combinations. The assessment is based on data on the occurrence of microorganisms in the specific products, the dosage of the microorganism needed to cause disease, how severe a disease it causes, average number of cases per year, and how much of the specific product is eaten.

Norovirus in berries ranks highest, followed by salmonella, norovirus and E. coli in lettuce. In general, berries, lettuce, sprouts, tomatoes and melons are at the top of the ranking. The results are largely consistent with what similar European and American risk rankings have found.

The authorities can use the results to evaluate the effect of control measures and changing consumption patterns as well as to prioritise initiatives aimed at strengthening food safety.

For this project the National Food Institute has developed a tool that can be used to rank combinations of products and disease-causing microorganisms for groups of people with different consumption patterns. The tool can also be used to update the risk ranking when new control data is available.

Fresh fruit and vegetables can contain disease-causing microorganism e.g. if they have been watered or washed with contaminated water, or they have been harvested or handled by people who have inadequate hand hygiene. Consumers can minimise the risk of disease by washing produce thoroughly and by following any instructions related to heat treatment

Read more

See the entire report: Risikorangering af sygdomsfremkaldende mikroorganismer i frisk frugt og grønt (pdf – available in Danish only).

The project defines fresh fruit and vegetables as fresh, unprocessed, ready-to-eat fruit and vegetable products, which are typically eaten without any further heat treatment or processing by the consumer. Also included are baby corn and snow peas, which are sometimes eaten without heeding advice for heat treatment. Frozen berries, which have often been associated with outbreaks of disease, are also included.

Is rainwater safe for domestic use? Prevalence of virulence genes associated with pathogenic Escherichia coli strains isolated from domestically harvested rainwater during low- and high-rainfall periods

There’s no drinking from the hose in our back concrete.

My grandparents had rain barrels: metal barrels that collected water off the roof to be used – I don’t know where they used it, maybe in laundry.

But in drought-ridden Brisbane, where they have a 200-year flood every 20 years, these fancy collection tanks (right) are standard.

Water is collected from the roof and stored in these tanks, and used through a separate plumbing system for toilets, dishwashers, laundry rainwater.brisbane.feb.14and watering with a hose.

As I water my collection of fruit trees and plants, I wonder about E. coli and other levels of potentially dangerous bacteria that accumulate in these tanks, and are then dispersed onto growing plants that may be eaten raw.

I don’t know the answers.

Some researchers in South Africa gave it a shot. Abstract below.

The possible health risks associated with the consumption of harvested rainwater remains one of the major obstacles hampering its large-scale implementation in water limited countries such as South Africa. Rainwater tank samples collected on eight occasions during the low- and high-rainfall periods (March to August 2012) in Kleinmond, South Africa, were monitored for the presence of virulence genes associated with Escherichia coli. The identity of presumptive E. coli isolates in rainwater samples collected from 10 domestic rainwater harvesting (DRWH) tanks throughout the sampling period was confirmed through universal 16S rRNA PCR with subsequent sequencing and phylogenetic analysis. Species-specific primers were also used to routinely screen for the virulent genes, aggR, stx, eae, and ipaH found in enteroaggregative E. coli (EAEC), enterohemorrhagic E. coli (EHEC), enteropathogenic E. coli (EPEC), and enteroinvasive E. coli, respectively, in the rainwater samples. Of the 92 E. coli strains isolated from the rainwater using culture based techniques, 6% were presumptively positively identified as E. coli O157:H7 using 16S rRNA. Furthermore, virulent pathogenic E. coli genes were detected in 3% (EPEC and EHEC) and 16% (EAEC) of the 80 rainwater samples collected during the sampling period from the 10 DRWH tanks. This study thus contributes valuable information to the limited data available regarding the ongoing prevalence of virulent pathotypes of E. coli in harvested rainwater during a longitudinal study in a high-population-density, periurban setting.

Produce, food safety culture and Brad Pitt

Brad Pitt toured Sydney Harbour and tried Vegemite, first time for the Missouri native.

I got to hang out at Darling Harbor in Sydney and chat with some Australian produce folks; some wanted to talk more, some wanted to throw me in the get.that.finger.out.of.your.ear.airplaneHarbour with concrete shoes.

Amy, my lovely and loving partner, quipped, “a typical Powell talk. Now get Sorenne ready and let’s go” or something like that.

(She’s actually a great counselor for my whines, anxieties and insecurities.)

I was speaking at the Australian Produce Marketing Association gabfest about food safety culture stuff.

I asked the delegates if they enjoyed the raw sprouts on their salad the night before, stated how many times I go to food safety things and get served raw sprouts (even in my own university) and suggested why that may not be a great idea.

(30 minutes after I was done talking, yet another sprout recall, this time Salmonella in Canada.)

I told them how we took the kid out to get some chips along Darling Harbor, and since they were served with aioli, I asked the server if the aioli was made with raw eggs (because Australia has a raw egg problem, most recently 140 sick in Canberra). She didn’t know but asked the chef, and the answer was yes.

I asked for tomato sauce instead (ketchup).

I complimented the Expo Center for having paper towels in the bathrooms, a rarity in Australia, but that the water flow was almost non-existent and two-darling.harbor.jun.13out-of-three sinks did not respond to the hand activation (vigorous water flow, rubbing and the friction of drying with paper towel are the key components of good handwashing).

I told them about a whole bunch of outbreaks, and one grower said I used scare tactics, and I said 33 people dying from eating rock melon (cantaloupe) wasn’t really a scare tactic, just what’s out there.

Like the 99 now sick from Hepatitis A in organic frozen berries.

I talked about food safety culture, tools like infosheets, repeated, rapid, reliable and relevant messages, about Frank and Chris and Ben and Amy and how they had all influenced my thoughts on the topic, but that to really seal the culture deal, growers and retailers had to brag about it.

I talked about the cantaloupe growers in California who have adopted some mandatory audit-inspection things, and all the problems and outbreaks that happen with places that have audits and inspections, and that big boys and girls take care of their own problems and get help when they need it.

I said how disappointed I was that as a consumer, there will be no label on these inspected cantaloupe, so as a consumer, I have no way of knowing whether a particular grower had even thought about microbiological food safety or was any good at it.

I tried to be triumphant and said, this isn’t a crisis, it’s an opportunity, for all you good Australian growers to get ahead of the curve, put in place the data collection and risk management efforts, the food safety culture, and go brag about it.

All the usual stuff.

And largely, the usual response.

I’m thankful for the opportunity to chat with growers and retailers – I always liked that – and thankful for the opportunity to clarify in my cobwebs a few things about what I should be doing.

But I’m no Brad Pitt.

I don’t want to be.

And get your finger out of the Vegemite. You don’t know where that finger’s been.


Water and fresh produce; does it matter?

Water is sortofa big thing in agriculture.

For the past 15 years I’ve had lively chats with growers of fresh produce about the quality of irrigation water. When the E. coli O157:H7 outbreak happened in two fistin wilsonWalkerton, Ontario, 13 years ago, those discussions became more heated.

My farmer friend Jeff wanted to know more and wanted to know what he could do because, as he said all those years ago, if a farmer has to choice between using potentially crap water or losing a crop, they’ll use the potentially crap water.

Things haven’t progressed much in the way of interventions, other than don’t bathe fresh produce in cow poop.

But under the Food Safety Modernization Act, growers in the Idaho-Eastern Oregon onion growing region, the nation’s largest in terms of volume, worry the rules will threaten their livelihood.

Growers say almost none of the surface water will meet the new standards.

And the science continues to be continuously vague.

Pahl et al reported in the Journal of Food Protection this month there was little correlation between indicator pathogens in water and indicator pathogens on tomatoes; maybe they didn’t stick.

Won et al reached similar conclusions in the same issue of JFP.

So how does this science feed into produce policy?

Comparing source of agricultural contact water and the presence of fecal indicator organisms on the surface of ‘juliet’ grape tomatoes

Journal of Food Protection,Number 6, June 2013, pp. 928-1108 , pp. 967-974(8)

Pahl, Donna M.; Telias, Adriana; Newell, Michael; Ottesen, Andrea R.; Walsh, Christopher S.


Consumption of fresh tomatoes (Solanum lycopersicum) has been implicated as the cause of several foodborne illness outbreaks in the United States, most notably in cases of salmonellosis. How the levels of fecal indicator organisms (FIOs) in water relate to the counts of these microorganisms on the tomato fruit surface is unknown, although microbial water quality standards exist for Onion Harvest2agricultural use. This study utilized four types of FIOs currently and historically used in microbial water quality standards (Enterobacteriaceae, total coliforms, fecal coliforms, and Escherichia coli) to monitor the water quality of two surface ponds and a groundwater source. The groundwater tested contained significantly lower counts of all FIOs than the two surface water sources (P < 0.05). Considerable variability in bacterial counts was found in the surface water sources over the course of the season, perhaps explained by environmental variables, such as water temperature, pH, precipitation, and air temperature (R2 of 0.13 to 0.27). We also monitored the fruit surface of grape tomatoes treated with overhead applications of the different water sources over the 2009 and 2010 growing seasons. The type of water source and time of year significantly affected the populations of FIOs in irrigation water (P < 0.05). Despite up to 5-log differences in fecal coliforms and 3-log differences in E. coli between the water sources, there was little difference in the populations measured in washes taken from tomato fruits. This lack of association between the aforementioned FIOs present in the water samples and on the tomato fruit surface demonstrates the difficulty in developing reliable metrics needed for testing of agricultural water to ensure the effectiveness of food safety programs.

Absence of direct association between coliforms and Escherichia coli in irrigation water and on produce

Journal of Food Protection, Number 6, June 2013, pp. 928-1108 , pp. 959-966(8)

Won, Gayeon; Schlegel, Pamela J.; Schrock, Jennifer M.; LeJeune, Jeffrey T.


Irrigation water is considered a potential source of preharvest pathogen contamination of vegetables. Hence, several organizations have recommended microbiological standards for water used to irrigate edible plants. The purpose of this study was to determine the strength of association between microbial quality indicators (coliforms and Escherichia coli) in irrigation water and on irrigated vegetables. Data analyzed included original results from a cross-sectional study conducted in the Midwestern United States during summer 2009 and information presented in two previously published studies performed in France and Portugal to investigate microbial quality of irrigation water and watered produce. In the cross-sectional study, repetitive PCR (rep-PCR) was used to characterize genetic relatedness of E. coli isolates from water and vegetables. No significant correlations were found between fecal indicators on leafy greens (lettuce and parsley, n = 91) or fruit (tomatoes and green peppers, n = 22) and those found in irrigation water used in the cross-sectional study (P > 0.40) or in the previously published data sets (data set 1: lettuce and waste irrigation water, n = 15, P > 0.40; data set 2: lettuce and irrigation water, n = 32, P = 0.06). Rep-PCR banding patterns of E. coli strains were all distinguishable among the pairs of E. coli isolates recovered from produce and irrigation water on the same farm. From the available data, the concentration of indicator organisms based on a single measure of irrigation water quality was not associated with the presence of these indicators on produce. In the absence of additional information, the use of a single microbial water quality parameter as an indicator of produce safety is of limited value for predicting the safety of the produce.

What’s the worst thing to say to a farmer? Hi, I’m from the government, I’m here to help

We figured out about 15 years ago that the worst thing to say to a farmer was, Hi, I’m from the government, I’m here to help, cause we hung out with farmers. The U.S. Department of Agriculture and the Food and Drug Administration apparently hasn’t figured this out, and went all gushy about how the two agencies are sharing people and resources to develop new produce regs.

Farmers across the nation were cleaning themselves after hearing the news from Washington.

USDA’s fresh produce chief will join FDA to develop new food safety rules, as part of a cooperative initiative between FDA and the U.S. Department of Agriculture (USDA). Today’s announcement comes amid beefed up outreach efforts with key agriculture and safe food stakeholders to better share and exchange produce safety ‘best practices’ and ideas.”

Will this result in fewer sick people? No . Is it complete bureau-speak that no one, especially those that grow fresh produce for a nation, will care about? Yes. Saturday Night Live captured the do-nothingness that has already cloaked the Obama change administration.

Raw seafood should not be packed and sold with fresh produce

It’s the biggest thing to happen in Manhattan (Kansas) grocery shopping … at least since we went away a few weeks ago.

The Hy-Vee opened.

And the Kroger-owned Dillon’s where we usually shopped is making some changes.

The first time we visited our usually bustling Dillon’s after the Hy-Vee opened, the place was a ghost town. Row after row of marked down products and a sense of malaise. We asked an employee why it was so quiet and he said, “It’s quiet?”

By yesterday, however, the pace at Dillon’s had picked up, and some new products had been added as well as a small demonstration kitchen near the meat aisle.

One of the new products was this (above right). Raw (previously frozen) scallops, packed with cherry tomatoes and lettuce. This seems like an exceedingly bad idea – microbiologically.

Restaurateurs willing to pay more for safer fresh produce

It’s difficult to predict how individuals and organizations will actually react (I’m suspicious of self-reported surveys) but at the PMA foodservice expo the below data was released suggesting that  89% of 510 surveyed restaurant operators would be "willing to pay more for guaranteed-safe fresh fruits, vegetables and leafy greens".

From the press release:

Restaurateurs are willing to pay more for produce that is guaranteed to be safe, according to research unveiled here Saturday during the Produce Marketing Association’s annual Foodservice Conference & Exposition.

Traceability even made it into the discussion:

More than three-fourths, or 76 percent, of the restaurant owners or restaurant purchasing agents interviewed in a nationwide phone survey in April and 10 chain purchasing executives interviewed in June said they would be willing to pay more for produce that was traceable from the farm to the restaurant to enable quicker action when contamination is discovered.

Marketing fresh produce food safety, where producers or wholesalers tell the story of employing GAPs, release data on their sampling strategies and tell folks why what they do is so important is the next step. Don’t just stop at the downstream buyers like retailers and foodservice, go right to the consumer.

Calls for mandatory government inspection is akin to mandatory restaurant inspection — it sets a bare minimum standard, is a snapshot in time, and has little to do with future outbreaks of food poisoning.
Rules and regulations look pretty on paper. But they are not comforting to those 76 million Americans who get sick from the food and water they consume each and every year. Instead, every grower, packer, distributor, retailer and consumer needs to adopt a culture that actually values safe food.

And market it. Tell the world, put all the information on your website. Tweet what you’re doing. Put up webcams.

The caveat is that you have to be able to back it up — that you are employing the best available science and management strategies to reduce risk.

The first company that can assure consumers they aren’t eating poop on fresh produce, will make millions and capture markets.

Fresh basil and bird poop

Last year, with Amy’s guidance, was the first year I really started cooking with fresh herbs. Basil and tomato (and formerly cheese, right), fresh pesto, bruschetta, it’s all good.

Except for the bird poop.

Here are a couple of our basil leaves with some semi-fresh bird plops – similar to the ones I washed off the car earlier today. When preparing dishes with fresh herbs, wash thoroughly (which can be difficult) or cook the poop out. Or both.

Michelle Obama promotes fresh produce; how about microbiologically safe produce?

The New York Times continues the fascination with all things Obama this morning as it reports on First Lady Michelle’s focus on fresh produce.

“You know, we want to make sure our guests here and across the nation are eating nutritious items. Collect some fruits and vegetables; bring by some good healthy food. We can provide this kind of healthy food for communities across the country, and we can do it by each of us lending a hand.”

In a speech at the Department of Agriculture last month, Mrs. Obama described herself as “a big believer” in community gardens that provide “fresh fruits and vegetables for so many communities across this nation and world.”

I am too. Brought the seedlings in yesterday as a temporary cold snap hit Kansas, but the greens and asparagus will soon be sprouting from the family garden. I also know fresh produce is also the biggest source of foodborne illness today in the U.S. That’s because it’s fresh, and anything that comes into contact has the potential to contaminate.

So, yeah Michelle, promote the produce, but organic and local do not mean safe. Play up those producers who responsibly manage microbial risks. And if you’re going to put your kids dining habits front and center, you really don’t want them barfing.

Kristen Schaal, otherwise known as Mel from Flight of the Conchords, offered her take on First Lady Michelle last night on the Daily Show.

Fresh produce and food banks

‘Tis the season for giving, and increasingly, food banks are distributing fresh produce.

The New York Times reported earlier this month,

“… food banks are preparing ready-to-eat meals, opening their own farms and partnering with institutions as varied as local supermarkets and state prisons to help gather and process food. They are also handling much more fresh produce, which requires overhauling the way they store and distribute food.”

What the story doesn’t mention is the risks of foodborne illness associated with fresh produce and how best to manage those risks.

Years ago, I went to an industrial kitchen that produced meals for several Toronto food banks to review their food safety protocols. It was impressive, and whatever fresh produce they got went into soups and stews, for food safety and preservation reasons.

I’m all for increased consumption of fresh produce, through food banks and elsewhere. But acknowledge and manage the risks.