Going public (not): 252 sick, I dead from E. coli in UK, yet officials were silent

Be the bug.

leek.e.coliThat’s what I tell people when they recite the different-cutting-board mythology as somehow, raw vegetables – grown in dirt and water from who knows where – are immune from E. coli and other bugs.

And talk about the bugs.

That raises awareness and helps people from getting sick.

But the UK, and their piping hot cooking technology, doesn’t believe in saying much.

Stuffed shirt approach.

While the paper below summarizes the outbreak four years later, it says nothing about the responsibility of health types – on the public dime — to make their information public.

 Between December 2010 and July 2011, 252 cases of STEC O157 PT8 stx1 + 2 infection were reported in England, Scotland and Wales. This was the largest outbreak of STEC reported in England and the second largest in the UK to date.

Eighty cases were hospitalized, with two cases of hemolytic uremic syndrome and one death reported. Routine investigative data were used to generate a hypothesis but the subsequent case-control study was inconclusive. A second, more detailed, hypothesis generation exercise identified consumption or handling of vegetables as a potential mode of transmission. A second case-control study demonstrated that cases were more likely than controls to live in households whose members handled or prepared leeks bought unwrapped [odds ratio (OR) 40, 95% confidence interval (CI) 2·08-769·4], and potatoes bought in sacks (OR 13·13, 95% CI 1·19-145·3). This appears to be the first outbreak of STEC O157 infection linked to the handling of leeks.

 A large Great Britain-wide outbreak of STEC O157 phage type 8 linked to handling of raw leeks and potatoes

Epidemiology and Infection / Volume 144 / Issue 01 / January 2016, pp 171-181



Taylor Farms produce mixture fingered in Costco chicken salad/E. coli O157 outbreak

A retailer or food service operator is only as good as the ingredients they use. Even with the best internal food safety programs, a good food safety culture includes supplier standards and verifications. Audits and inspections are never enough.

According to the Associated Press, Costco believes that contamination of their rotisserie chicken salad is linked to produce.costco.chicken.salad_.nov_.15

Costco officials say testing has pointed toward a vegetable mix from a California food wholesaler as the source of E. coli in the company’s chicken salad that has been linked to an outbreak that has sickened 19 people in seven states.

Craig Wilson, Costco vice president of food safety and quality assurance, said Wednesday he was told by the Food and Drug Administration that the strain of E. coli seems to be connected to an onion and celery mix.

Wilson says the company uses one supplier for those vegetables in the chicken salad sold in all its U.S. stores.

He says one additional test is needed to confirm that the vegetables carried the same E. coli strain connected with the outbreak.

Wilson identified the supplier as Taylor Farms in Salinas, California.

Testing a necessary evil of food safety: FDA’s microbiological surveillance sampling

As part of the U.S. Food and Drug Administration’s risk-based and preventive approach to food safety, which is at the core of the FDA Food Safety Modernization Act, the agency began developing a new, more robust surveillance sampling approach in 2014. As the agency moves forward with this approach, it will continue to refine procedures based on lessons learned. The goals of the surveillance sampling are to keep contaminated products from reaching consumers and to facilitate a greater understanding of hazards.

food.lab.testingFDA will publish information regarding test results on the web, including total number of samples collected/tested, and collection date, sample type, and pathogen detected for positive samples.

The Sampling Approach

Under the new sampling approach, the FDA is collecting a statistically determined number of samples of targeted foods over a shorter period of time—12 to18 months—to ensure a statistically valid amount of data is available for decision making.  The sampling approach will help the FDA determine if there are any common factors among positive findings such as season, region, and whether the product was produced domestically or imported.  The FDA’s past approach to microbiological surveillance sampling has been to collect a relatively small number of samples for many different commodities over many years. 

The sampling design for each food represents what U.S. consumers are likely to find in the marketplace. Accordingly, the agency has considered the volume of the target food that is imported and produced domestically and the number of states/countries that produce the target food.

During the first year of this new effort, the FDA focused on sprouts, whole fresh avocados, and raw milk cheese (aged 60 days). The FDA collected more than 800 samples total and tested them for Salmonella, Listeria monocytogenes and E. coli O157:H7. For fiscal year 2016, The FDA will sample and test cucumbers and hot peppers for Salmonella and E. coli O157:H7, taking 1,600 samples of each commodity. The agency also plans to test hot peppers for Shiga toxin producing E. coli. The FDA will conduct whole genomic sequence testing on any samples that test positive. In the future, the number of samples collected of a targeted commodity may vary, depending on the question(s) the FDA intends to answer. Data from the sampling assignments already conducted will be released soon.

The FDA will evaluate the data or results generated throughout the sample collection period and use the data to inform the agency’s short and longer term decision making. By developing these data sets, the FDA seeks to identify potential vulnerabilities and ways to enhance the food safety system.

Depending on the results, the FDA may react or take certain steps, such as:

  • Decreasing sampling, if few positive samples are obtained;
  • Implementing more targeted sampling if trends are identified; for example, if positive samples come from a specific geographic region, a specific facility, or during a particular season;
  • Follow-up inspections;
  • Working with state or international regulatory partners to take corrective actions and implement preventive controls;
  • Developing new or enhanced industry guidance; and
  • Conducting outreach and information sharing to better protect consumers.


Produce: ‘Washing it good enough is going to maybe reduce the risk’

“People get ill,” says Ted Labuza, a professor of food science at the University of Minnesota. “If you really want to reduce your chances, washing it good enough is going to maybe reduce the risk.”

lettuce.skull.e.coli.O145Labuza says people should scrub, rather than rinse, their fruits and vegetables for 30 seconds.

“It should really be to one rhyme of Mary Had a Little Lamb,” he says.

In this video from the University of Minnesota Extension, the difference between a quick rinse and deep wash with your hands is dramatic.

“The friction is scraping it off, but you don’t want to scrape it off so much that you’re damaging the fruits and vegetables,” Labuza says.

He says a good wash will remove about 90% of the bacteria. For most healthy people, that’s enough to avoid getting sick from a variety of food-borne illnesses, like E. coli, salmonella and listeria. Older people and children are generally at greater risk.

Studies have shown that water and friction offers a similar clean to commercial vegetable washes or diluted vinegar.

But, in rare cases, the best cleaning won’t help. For example, leafy fruits and vegetables that have been irrigated with bacteria-infected water can be dangerous.

“We do know with things like lettuce and spinach, sometimes the bacteria crawls up through the channels and nothing is going to work there,” Labuza says.

Bleach is your friend: produce contamination in the Middle East

My former dean was known as Dr. Clorox while serving in Vietnam.

produce.cloroxI used to give these training sessions to food types headed for Iraq and Afghanistan from Fort Riley (in Manhattan, Kansas) and would sheepishly say, I have no idea what you’re going to face in terms of potable water, but bleach is your friend.

We take so much for granted.

In the developing countries, inaccessibility to safe water, lack of agricultural infrastructures and limitations to implementing good agricultural practices (GAP) are persistent challenges.

To understand the spread of hazards and identify critical areas of transmission in the food chain, a total of 90 samples of raw salad vegetables (parsley, lettuce, radish) were collected from farms and post-harvest washing facilities (n = 12) in an extensively cultivated area in Lebanon, the Bekaa Valley and from wholesale market stalls traced back to surveyed fields.

Our results showed high geometric mean indicator levels ranging from <0.7 to 7 log CFU/g (Escherichia coli), 1.69–8.16 log CFU/g (total coliforms), <0.7–8.39 log CFU/g (Staphylococcus aureus). The mean counts of total coliforms and E. coli on fresh produce followed an increasing trend from fields to the markets indicating potential sources of fecal contamination throughout the food chain. Of more concern was the presence of pathogens Listeria monocytogenes (14%) and S. aureus (45.5%) in fresh produce from harvest to retail, and Salmonella spp. was detected in 6.7% of the raw vegetables from the post-harvest washing areas.

the_first_bleach_bottle_by_thebleachbottle-d5h2xeyThese results along with our observations highlight shortfalls in hygienic farming and postharvest practices, including the use of inappropriately treated manure and chicken litter to fertilize the crops on the fields which contributed to the high levels of S. aureus in the product at retail. Unregulated use of wash water, inadequate transportation and storage conditions with risks of cross contamination was also identified.

Suggested control measures should mitigate the risks at the source and put emphasis on developing strict policies on monitoring the safety of water sources and on the application of the good agricultural and hygienic practices (GAP, GHP) on primary production stages, washing, transportation and storage at retail.

 Understanding the routes of contamination of ready-to-eat vegetables in the Middle East

Food Control, Volume 62, April 2016, Pages 125–133

Dima Faour-Klingbeil, Muhammad Murtada, Victor Kuri, Ewen C.D. Todd



Guidelines are nice, enforcement II: Will fewer people barf under new produce and import rules (no)

New produce safety rules from the government Friday are intended to help prevent the kind of large-scale outbreaks of foodborne illness that occurred over the past decade linked to fresh spinach, cantaloupes, cucumbers and other foods.

rulesUnder the rules, the government soon will have new oversight of the farms that grow Americans’ food. That means, for example, making sure workers are trained to wash their hands, irrigation water is monitored for harmful bacteria and animals do not leave droppings in fields.

The regulations are tailored to cover foods and growing methods that pose the greatest risk, and they target produce such as berries, melons, leafy greens and other items usually eaten raw and more prone to contamination. A farm that produces green beans that will be cooked and canned, for example, would not be regulated. There are also exemptions for smaller farms.

The rules require farmers to test irrigation water quality, regularly train workers on the best health and hygiene practices, and monitor wildlife that may intrude on growing fields, among other measures.

Compared with the original proposal, the final rule requires less stringent standards for irrigation water quality and reduces the frequency of testing, in some cases. The organic industry had expressed concerns about the rules, especially because many organic farmers use raw manure as fertilizer and try to treat irrigation water with fewer chemicals.

Advocates for food safety laws have cited the pressing need after several high-profile foodborne illness outbreaks. In 2006, E. coli in fresh spinach was linked to several deaths, including a 2-year-old. A 2011 outbreak of listeria linked to cantaloupes killed 30 people. This year, four people have died in a salmonella outbreak linked to Mexican cucumbers.

Also on Friday, the FDA released new rules to ensure the safety of food imported for the U.S. market.

These rules could help prevent against outbreaks such as the salmonella in Mexican cucumbers or cyclospora illnesses linked to Mexican cilantro. The FDA said the cilantro was grown in fields where American investigators found toilet paper and human feces.

Be the bug: Kitchen utensils spread bacteria between foods says Georgia study

In a recent study funded by the U.S. Food and Drug Administration, University of Georgia researchers found that produce that contained bacteria would contaminate other produce items through the continued use of knives or graters–the bacteria would latch on to the utensils commonly found in consumers’ homes and spread to the next item.

lettuce.skull.e.coli.O145Unfortunately, many consumers are unaware that utensils and other surfaces at home can contribute to the spread of bacteria, said the study’s lead author Marilyn Erickson, an associate professor in the College of Agricultural and Environmental Sciences’ department of food science and technology.

“Just knowing that utensils may lead to cross-contamination is important,” Erickson said. “With that knowledge, consumers are then more likely to make sure they wash them in between uses.”

Erickson has been researching produce for the past 10 years. Her past work has mainly focused on the fate of bacteria on produce when it’s introduced to plants in the field during farming.

In 2013, she was co-author on a study looking at the transfer of norovirus and hepatitis A between produce and common kitchen utensils–finding that cutting and grating increased the number of contaminated produce items when that utensil had first been used to process a contaminated item.

This study, published in Food Microbiology, is similar in that it considers the influence that knives and graters have on the transfer of pathogenic bacteria to and from produce items. She urges consumers to realize that these germs can spread in their kitchens as well.

Researchers have known that poor hygiene and improper food preparation practices in a consumer’s home can lead to foodborne illnesses, but considering what practices in the kitchen are more likely to lead to contamination has not been examined extensively.

“The FDA was interested in getting more accurate numbers as to what level of cross-contamination could occur in the kitchen using standard practices,” Erickson said.

Close-up of a woman preparing vegetables on a cutting board.In her recent study, Erickson contaminated many types of fruits and vegetables in her lab–adding certain pathogens that often can be found on these foods, such as salmonella and E. coli.

Using a knife, Erickson would cut into things like tomatoes or cantaloupe and other types of produce to see how easily the bacteria could spread when the knife was continuously used without being cleaned. Because they “were looking at what would be the worst-case scenario,” she said, Erickson and study co-authors did not wash between cutting these different produce items.

Researchers also grated produce, like carrots, to see how easily the pathogens spread to graters. They found that both knives and graters can cause additional cross-contamination in the kitchen and that the pathogens were spread from produce to produce if they hadn’t washed the utensils.

“A lot of the broken up material and particles from the contaminated produce remained on the graters,” said Erickson, who conducts her research at the UGA Center for Food Safety in Griffin. “Then if you were to shred another carrot or something else immediately after that, it gets contaminated, too.”

The study also found that certain fruits and vegetables spread pathogens to knives to different degrees.

“For items like tomatoes, we tended to have a higher contamination of the knives than when we cut strawberries,” Erickson said. “We don’t have a specific answer as to why there are differences between the different produce groups. But we do know that once a pathogen gets on the food, it’s difficult to remove.”

Knives and graters aren’t the only utensils in the kitchen consumers should be worried about. Erickson has also helped study the role brushes and peelers have on the transfer of dangerous kitchen bacteria.

In concurrent studies, Erickson found that scrubbing or peeling produce items–like melons, carrots and celery–did not eliminate contamination on the produce item but led to contamination of the brush or peeler. Even when placed under running water, the utensils still became contaminated; however, the ability to cross-contaminate later produce items depended on the brush type and the pathogenic agent.

These studies combined give researchers a better idea as to how common cross-contamination is in the kitchen–even when just using standard practices.

Erickson explained there is a small chance of buying fruits and vegetables contaminated with bacteria, but the problem can occur–whether the product is store-bought or locally grown.

Additional study co-authors were Qing Wang, a doctoral student at the University of Delaware, and Jean Liao, a research professional; and associate professors Jennifer Cannon and Ynes Ortega with UGA’s Center for Food Safety.

The study, “Contamination of knives and graters by bacterial foodborne pathogens during slicing and grating of produce,” is available at http://www.sciencedirect.com/science/article/pii/S0740002015001306.

Sanitizers and produce: What works?

The aim of this study was to perform a meta-analysis of the effects of sanitizing treatments of fresh produce on Salmonella spp., Escherichia coli O157:H7, and Listeria monocytogenes.

lettuce.skull.noroFrom 55 primary studies found to report on such effects, 40 were selected based on specific criteria, leading to more than 1,000 data on mean log reductions of these three bacterial pathogens impairing the safety of fresh produce. Data were partitioned to build three meta-analytical models that could allow the assessment of differences in mean log reductions among pathogens, fresh produce, and sanitizers. Moderating variables assessed in the meta-analytical models included type of fresh produce, type of sanitizer, concentration, and treatment time and temperature. Further, a proposal was done to classify the sanitizers according to bactericidal efficacy by means of a meta-analytical dendrogram.

The results indicated that both time and temperature significantly affected the mean log reductions of the sanitizing treatment (P < 0.0001). In general, sanitizer treatments led to lower mean log reductions when applied to leafy greens (for example, 0.68 log reductions [0.00 to 1.37] achieved in lettuce) compared to other, nonleafy vegetables (for example, 3.04 mean log reductions [2.32 to 3.76] obtained for carrots). Among the pathogens, E. coli O157:H7 was more resistant to ozone (1.6 mean log reductions), while L. monocytogenes and Salmonella presented high resistance to organic acids, such as citric acid, acetic acid, and lactic acid (∼3.0 mean log reductions). With regard to the sanitizers, it has been found that slightly acidic electrolyzed water, acidified sodium chlorite, and the gaseous chlorine dioxide clustered together, indicating that they possessed the strongest bactericidal effect.

The results reported seem to be an important achievement for advancing the global understanding of the effectiveness of sanitizers for microbial safety of fresh produce.

 Meta-analysis of the Effects of Sanitizing Treatments on Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes Inactivation in Fresh Produce

Applied and Environmental Microbiology, Volume 81, Number 23, December 2015

L Prado-Silva, V Cadavez, U Gonzales-Barron, A Rezende, A Sant’Ana



Everything old is new again: Produce-related outbreaks

About 20 years ago, as a (relatively) young professor, I told a national meeting of farm groups in Canada that, drawing largely on the work of Larry Beuchat from the University of Georgia, technology was improving and outbreaks in foods like fresh produce could now be traced back to the farm.

foodborne.virus.produceI was naïve and didn’t realize how cliché that statement would become, underestimating producer organization influences and political realities.

I was in it for safer food – fewer people barfing.

On Oct. 23, 2015, according to The Packer, a food safety workshop at the Produce Marketing Association’s Fresh Summit heard that DNA fingerprinting and other scientific methods — as well as social media — are changing the face of food illness outbreaks.

Art Liang, the Centers for Disease Control and Prevention’s senior advisor food safety for the divisions of foodborne, waterborne and environmental diseases said, “There are more outbreaks, but the outbreaks are smaller, the good news part of this. How do we know that the things we say are foodborne outbreaks are actually foodborne? Produce is often implicated but it can be a retail or food handling issue. There are all sorts of ways (contaminants) can be transmitted.”

The produce industry is working in unique times, said Bob Whitaker, PMA’s chief science and technology officer.

“We are at an interesting juncture in our history to where data and some of the convergence of data on DNA, technologies and gene regulation will help us better understand some of the issues around public health,” he said. “Those are being driven by our abilities to use and analyze data.”

It’s not so unique, Dr. Bob.

Foodborne viruses in fresh produce

Norovirus (NoV) and hepatitis A virus (HAV) are the most important foodborne viruses. Fresh produce has been identified as an important vehicle for their transmission.

foodborne.virus.produceIn order to supply a basis to identify possible prevention and control strategies, this review intends to demonstrate the fate of foodborne viruses in the farm to fork chain of fresh produce, which include the introduction routes (contamination sources), the viral survival abilities at different stages, and the reactions of foodborne viruses towards the treatments used in food processing of fresh produce. In general, the preharvest contamination comes mainly from soli fertilizer or irrigation water, while the harvest and postharvest contaminations come mainly from food handlers, which can be both symptomatic and asymptomatic. Foodborne viruses show high stabilities in all the stages of fresh produce production and processing. Low-temperature storage and other currently used preservation techniques, as well as washing by water have shown limited added value for reducing the virus load on fresh produce. Chemical sanitizers, although with limitations, are strongly recommended to be applied in the wash water in order to minimize cross-contamination. Alternatively, radiation strategies have shown promising inactivating effects on foodborne viruses. For high-pressure processing and thermal treatment, efforts have to be made on setting up treatment parameters to induce sufficient viral inactivation within a food matrix and to protect the sensory and nutritional qualities of fresh produce to the largest extent.

Comprehensive Reviews in Food Science and Food Safety

Dan Li, Ann De Keuckelaere and Mieke Uyttendaele