All food can be contaminated: Huge recall of frozen fruits and vegetables after Listeria outbreak

The N.Y. Times has noticed the growing number of recalls linked to Listeria-positive frozen produce packed by CRF Frozen Foods in Pasco, Wash., but offers little perspective on why.

beaker.the.screamZero-tolerance is not discussed. Neither is the test-and-hold approach used by many frozen-produce packagers. And of particular note: During our tour of Ontario processing vegetable growers and processors 15 years ago, Chapman and I were told that almost all processing vegetables are blanched – not so much for food safety but for quality – except onions.

Back to the onions at the end.

Brittany Behm, a spokeswoman for the U.S. Centers for Disease Control and Prevention, told the Times the scale of the recall reflects the severity of the outbreak of the illness, Listeria, and of concerns about how the contaminated food might have “trickled down” into other products.

The processing plant, has voluntarily recalled more than 350 frozen foods — including carrots, onions, peaches and strawberries — that were sold in all 50 states and Canada and Mexico, and the EU. The recall began on April 23, with 11 frozen vegetables, but was significantly expanded on May 2.

Eight people sickened with the bacterium Listeria monocytogenes have been confirmed since 2013 — six in California and one each in Maryland and Washington, Ms. Behm said. All of the cases, involving patients 56 to 86 years old, resulted in hospitalizations.

The two people from Maryland and Washington died, but the authorities did not directly attribute their deaths to Listeria because they may have already had weakened immune systems or other illnesses, Ms. Behm said.

It was not clear how many packages were affected by the recall. A spokesman for the company, Gene Grabowski, did not respond to a phone call on Friday. He told The Associated Press that the CRF plant closed two weeks ago and that the company was trying to pinpoint the source of the contamination.

22xp-foodrecall_web2-master315“Unquestionably, this is a lot of product. … It reflects the severity of listeria as an illness, the long duration of illnesses and the outbreak and the long shelf life of the products,” said Matthew Wise, who leads the outbreak response team at the federal Centers for Disease Control and Prevention.

On May 14, 2016, Food Safety News reported that staff from the U.S. Food and Drug Administration inspected the CRF Frozen Foods LLC plant in Pasco, WA, from March 14-17.

The company stopped production at the plant April 25 after being notified by federal officials that frozen vegetables produced there had been linked by genetic testing to several people who had infections from Listeria monocytogenes.

The two-page FDA inspection report includes boilerplate citations of applicable sections of the federal Food, Drug and Cosmetic Act on its second page. The first page includes hand-written observations documenting:

a damaged plastic shovel used for food contact tasks;

chipping, cracking and missing pieces of plastic on food contact portions of equipment on the onion production line;

a plastic conveyor belt with missing plastic pieces on at least five legs that are in direct contact with onions;

utility knives used for trimming bad spots off onions that had initials etched on their blades; and

blue tape being used as a temporary repair on a cracked metal plate above a consumer pack line that was repacking product for export at the time of the inspection.

All of the examples cited by inspectors are cause of concern for the same reason — they mean it’s impossible to adequately clean the equipment that is in direct contact with food being produced.

“The materials and workmanship of equipment and utensils does not allow proper cleaning and maintenance,” according to the report.

“Investigations are ongoing to determine if food sources used to manufacture CRF Frozen Foods products could explain some of the illnesses,” FDA reported in its most recent update May 4.

One of those “food sources” could be onions from Oregon Potato Co., also located in Pasco, WA.

“March 2016 environmental samples collected by FDA from Oregon Potato Company, located in Pasco, WA, were found to be closely related genetically to seven of the isolates of ill people associated with this outbreak,” the FDA reported.

“Based on this information, Oregon Potato Company voluntarily recalled wholesale onion products, which led to subsequent downstream customer recalls, one of which publicly disclosed Oregon Potato Company as its product source.”


Whole genome sequencing confirms: Listeria in pre-packaged salad

We report on a case of listeriosis in a patient who probably consumed a prepackaged romaine lettuce–containing product recalled for Listeria monocytogenes contamination.

lettuce.skull.e.coli.O145Although definitive epidemiological information demonstrating exposure to the specific recalled product was lacking, the patient reported consumption of a prepackaged romaine lettuce–containing product of either the recalled brand or a different brand.

A multinational investigation found that patient and food isolates from the recalled product were indistinguishable by pulsed-field gel electrophoresis and were highly related by whole genome sequencing, differing by four alleles by whole genome multilocus sequence typing and by five high-quality single nucleotide polymorphisms, suggesting a common source.

To our knowledge, this is the first time prepackaged lettuce has been identified as a likely source for listeriosis. This investigation highlights the power of whole genome sequencing, as well as the continued need for timely and thorough epidemiological exposure data to identify sources of foodborne infections.

Use of whole genome sequencing and patient interviews to link a case of sporadic listeriosis to consumption of prepackaged lettuce

Journal of Food Protection®, Number 5, May 2016, pp. 696-889, pp. 806-809(4)

Jackson, K. A.; Stroika, S.; Katz, L. S.; Beal, J.; Brandt, E.; Nadon, C.; Reimer, A.; Major, B.; Conrad, A.; Tarr, C.; Jackson, B. R.; Mody, R. K.

14 sickened by Listeria in meat pies, UK, 2010-2013

An outbreak of listeriosis in England affecting 14 people between 2010 and 2012 and linked to the consumption of pork pies was investigated. All 14 individuals were older than 55 years, 12 were men, and 10 reported the presence of an underlying condition.

listeria4All were resident in or had visited either of two English regions and were infected with the same strain of Listeria monocytogenes.

In interviews with 12 patients, 9 reported eating pork pies, and individuals that consumed pork pies were significantly more likely to be infected with an outbreak strain than were individuals with sporadic cases of listeriosis infections in England from 2010 to 2012.

Pork pies were purchased from seven retailers in South Yorkshire or the East Midlands, and the outbreak strain was recovered from pork pies supplied by only the producer in South Yorkshire. The outbreak strain was also recovered from samples of finished product and from environmental samples collected from the manufacturer. The likely source of contamination was environmental sites within the manufacturing environment, and the contamination was associated with the process of adding gelatin to the pies after cooking.

Inadequate temperature control and poor hygienic practices at one of the retailers were also identified as possible contributory factors allowing growth of the pathogen.

Following improvements in manufacturing practices and implementation of additional control measures at the retailers’ premises, L. monocytogenes was not recovered from subsequent food and environmental samples, and the outbreak strain was not detected in further individuals with listeriosis in England.

An outbreak of human listeriosis in England between 2010 and 2012 associated with the consumption of pork pies

Journal of Food Protection®, Number 5, May 2016, pp. 696-889, pp. 732-740(9)

Awofisayo-Okuyelu, A.; Arunachalam, N.; Dallman, T.; Grant, K. A.; Aird, H.; McLauchlin, J.; Painset, A.; Amar, C.

A related paper assessed the microbiological quality of meat pies from retail sale in England, 2013, included a literature review that revealed a range of microbiological hazards responsible for food poisoning and meat pie consumption, and surveillance data from 1992 to 2012 from England indicated that C. perfringens was the most commonly reported cause of outbreaks of foodborne illness.

Journal of Food Protection®, Number 5, May 2016, pp. 696-889, pp. 781-788(8)

McLauchlin, Jim; Aird, Heather; Charlett, Andre; Elviss, Nicola; Fox, Andrew; Kaye, Moira; Willis, Caroline

Listeria: Is zero tolerance consistent with risk-reduction

Tom Karst of The Packer writes it doesn’t seem quite right that many fresh produce processors aren’t testing for listeria on food contact surfaces in their facilities. Aren’t belts and other parts of a processing plant that touch product an important place to look for pathogens that might be present on food? 

listeria4Yet, that is the way it is, based on industry’s evaluation of Food and Drug Administration Guidance. Because any finding of listeria on food contact surfaces could result in an immediate recall situation, many in the industry believe the FDA’s zero-tolerance policy inhibits companies from testing food contact surfaces. 

The FDA is considering changing some of their guidance on listeria testing. Industry experts a new version of the guidance by late this year or early next year.  Perhaps the FDA will give more flexibility for companies to test for the listeria species – indicating the presence of the family of bacteria, but not necessarily the dangerous Listeria monocytogenes strain. Perhaps the FDA will establish a tolerance level for Listeria monocytogenes, though that doesn’t seem likely.

Karst got some standard answers from government spokesthingies, but got a more proactive answer from Martin Bucknavage, a Pennsylvania State University Department of Food Science food safety extension specialist, who said fresh produce and other food companies have to do a better job of understanding the presence of listeria within their operations and take stronger corrective actions. Most of the testing now being done for listeria is pre-operational and on nonfood contact areas, which he said has limited use.

“They have got to get more proactive and get rid of it,” he said. “I think it is time to batten down the hatches, get aggressive on sampling and put this thing to bed.”

Doering: Label raw milk cheese

Ronald L. Doering, BA, LL.B. MA, LL.D., a past president of the Canadian Food Inspection Agency and now counsel in the Ottawa offices of Gowling WLG, writes in his Food in Canada column that the science keeps piling up.

ron.doeringIt is not safe to consume raw milk and its products. The U.S. Food and Drug Administration (FDA) recently announced studies that show again that pathogens from raw milk including tuberculosis, diphtheria, typhoid, Salmonella, Listeria, and many other bacterial infections make it unsafe for human consumption. A comprehensive study was released last month by Belgian authorities that concluded that “raw milk poses a realistic health threat due to possible contamination with human pathogens.” Interestingly, the same study found that there was “no substantial change in the nutritional value of raw milk or other benefits associated with raw milk consumption,” but that’s a story for another day. And, of course, the unfortunate proof keeps coming, with hundreds of outbreaks, many deaths and thousands of illnesses just in the last few years due to raw milk and raw milk cheese.

Just because raw milk and raw milk cheese are not as safe as if they were pasteurized doesn’t necessarily mean that they should be banned. That is why regulations around the world are so inconsistent. The sale of raw milk is illegal in Scotland, but legal in England, Wales and Northern Ireland (indeed our future king will drink nothing else, a fact that could be used by both sides of the debate!). South of the border the states are roughly evenly divided, but interstate commerce is banned. Raw milk and most raw milk cheeses are banned in Australia but legal in New Zealand. In Canada, the sale of raw milk directly to consumers is prohibited by a variety of provincial provisions and it is a federal crime to sell unpasteurized milk under B.08.002.2(1) of the Food and Drug Regulations.

Canada continues to allow the sale of raw milk cheeses aged over 60 days, but provides this clear warning: “Health Canada’s ongoing advice to pregnant women, children, older adults and people with a weakened immune system is to avoid eating cheese made from raw milk as it does present a higher risk of foodborne illness than pasteurized milk cheeses. If consumers are unsure whether a cheese is made from pasteurized milk, they should check the label or ask the retailer.”

raw-milk-cheeseWhen I first wrote about this issue three years ago I pointed out the regulatory absurdity of the last sentence in the Health Canada (HC) warning. There is no requirement to label and most retailers have no idea if the cheese is made from raw milk, and have no means to determine if it is. At the time I received an informal response to my article from a senior official advising me that before moving to mandatory labelling, HC was going to partner with FDA to do a risk assessment of raw milk cheese, focusing specifically on the risk of illness from Listeria monocytogenes. The results of this risk assessment were released last summer: “The risk of listeriosis from the consumption of soft-ripened cheese made from raw milk is substantially larger than that for consumption of soft-ripened cheese made from pasteurized milk and the 60-day aging regulation actually increases the risk of listeriosis for consumption of raw milk cheeses.” The risk was found to be from 50 to 160 times greater. This resulted in HC issuing a Voluntary Guidance to manufacturers that included suggestions to industry to do regular testing of both the raw milk and the cheese and that “Manufacturers should consider labelling their products with the words ‘made from raw or unpasteurized milk’ on the front panel display and/or in the list of the ingredients.”

The Guidance document seeks feedback from stakeholders before developing new “policy and/or regulatory options.” Here’s mine, again: stop the bureaucratic dithering and do what the Americans, Brits and Europeans have already done – make it mandatory for all manufacturers to label their raw milk cheeses. It’s useless, as they say, to try to reason someone out of something they didn’t reason themselves into, so if we can’t stop people from consuming raw milk and its products, then let’s at least ensure that it is not consumed unknowingly particularly by children, the elderly or expectant mothers. HC now requires unpasteurized juice to be labelled. Who’s against mandatory labelling of raw milk cheese?

Why not: Listeria in walnuts

United Natural Trading LLC, d/b/a Woodstock Farms Manufacturing, Edison, NJ, is voluntarily recalling a limited number of lots of conventional walnuts and walnut-containing products (see attachment for products and lot numbers) that were purchased from Gibson Farms and sold under the Nature’s Promise, Woodstock, Market Basket, and Woodfield Farms brands due to a possible health risk from Listeria monocytogenes

walnuts.sorenne.apr.11The lot numbers are printed on the back of each retail bag. The walnut and walnut-containing products were shipped to retailers and distributors in limited quantities throughout the United States.

The recall was issued as a precaution because a single sample in a finished product yielded a positive result for Listeria monocytogenes. The Company is coordinating closely with regulatory officials and has contacted its customers to ensure that any remaining recalled products are removed.

No illnesses have been reported in association with the recall and no other walnuts or products under the brands are being recalled.

Description                Lot Number  Best By Date 

Nature’s Promise Cranberry Trail Mix Net Wt. 12oz.   16082  Best By 9/17/16



                        16099  Best By 9/17/16


            16117  Best By 9/17/16       8826706612

Woodstock Walnut Halves &Pieces Net Wt. 6oz.          16092  Best By 4/1/17         4256300860

            16106  Best By 4/15/17       4256300860

Woodstock Cape Cod Cranberry Mix Net Wt. 10oz.    16079  Best By 9/17/16       4256300877

            16091  Best By 9/17/16       4256300877

            16098  Best By 9/17/16       4256300877

            16126  Best By 11/30/16     4256300877

Market Basket Walnuts Raw Net Wt. 7oz.          16083  Best By 3/23/17       4970540809

            16105  Best By 4/14/17       4970540809

Market Basket Cape Cod  Cranberry Trail Mix Net Wt. 10oz. 16106  Best By 9/17/16       4970540832

Woodfield Farms Walnuts Halves & Pieces Net Wt. 2.5lbs.     16112  Best By 4/21/17       7523900194

Nature’s Promise Walnuts Halves & Pieces Net Wt. 7oz.         16093  Best By 4/2/17         8826714404

            16110  Best By 4/19/17       8826714404

What made Listeria in 2011 cantaloupe outbreak so deadly?

In the fall of 2011, listeria-in-cantaloupe killed 33 people and sickened 147 in the U.S. Fault was found with the growers, the packing shed and dump tank where cantaloupes were washed before being shipped, and a porous food safety audit process.

cantaloupe.handBut was there something about the strains of Listeria involved that made this outbreak particularly deadly?

The 2011 listeriosis outbreak attributed to whole cantaloupe involved several genetically distinct strains of serotypes 1/2a and 1/2b that had not been previously reported in invasive listeriosis outbreaks.

Here we investigated the potential of strains from the 2011 cantaloupe outbreak to adhere, survive, and grow on cantaloupe rind and flesh and in juice extracted from cantaloupe at different temperatures (4, 8, and 25°C). All strains were able to adhere and grow, with ∼10-fold increases after 7 days at 4 or 8°C and after 24 h at 25°C, with a propensity for more growth on rind than on flesh or in extract. No significant differences in growth potential were noted among the different strains or between them and unrelated strains from other listeriosis outbreaks involving celery, deli meats, or hot dogs. Similarly to the cantaloupe outbreak strains, these other strains exhibited greater propensity for growth on rind than on flesh or in extract. Rinsing of cantaloupe fragments in sterile water resulted in temporary reductions of the populations by 50- to 100-fold, suggesting the potential of such washing to reduce risk if the produce is promptly consumed.

The absence of marked differences in adherence or growth between the cantaloupe outbreak strains and strains from other outbreaks highlights the need to further characterize the 2011 cantaloupe outbreak strains and elucidate potential biological attributes that contributed to their implication in the outbreak.

Capacity of Listeria monocytogenes strains from the 2011 cantaloupe outbreak to adhere, survive, and grow on cantaloupe

Journal of Food Protection®, Number 5, May 2016, pp. 696-889, pp. 757-763(7)

Martinez, Mira Rakic; Osborne, Jason; Jayeola, Victor Oladimeji; Katic, Vera; Kathariou, Sophia

Cutting cantaloupe and blaming consumers: Food safety starts on the farm

In 1998, the U.S. Department of Agriculture very publicly began to urge consumers to use an accurate food thermometer when cooking ground beef patties because research demonstrated that the color of meat is not a reliable indicator of safety.

cantaloupe.half_.sep_.12USDA Under Secretary for Food Safety at the time, Catherine Woteki, said, “Consumers need to know that the only way to be sure a ground beef patty is cooked to a high enough temperature to destroy any harmful bacteria that may be present is to use a thermometer.”

At the time, I said, no one uses a meat thermometer to check the doneness of hamburgers. The idea of picking up a hamburger patty with tongs and inserting the thermometer in sideways was too much effort (others insist the best way to use a tip sensitive digital thermometer is to insert into the middle of the patty at a 45 degree angle).

I was wrong.

Shortly thereafter, I started doing it and discovered, not only was using a meat thermometer fairly easy, it made me a better cook. No more burgers resembling hockey pucks, overcooked to ensure dangerous pathogens were gone. They tasted better.

By May 2000, USDA launched a national consumer campaign to promote the use of food thermometers in the home. The campaign featured an infantile mascot called Thermy who proclaimed, “It’s Safe to Bite When the Temperature is Right.”

Almost two decades later and I have the fervor of a born-again thermometerist, distributing them to friends, one meal at a time.

Sometime in the mid-2000s, in light of on-going outbreaks involving cantaloupe (rock melon) USDA started recommending that consumers wash the exterior to prevent dangerous microorganisms on the surface of the cantaloupe from coming into contact with the inner flesh.

I was not convinced.

And remain unconvinced (see video, below, from 2009).

cantaloupe.salmonella_0.featuredWhat is important that as soon as cantaloupe is chopped or cut in half, it needs to be kept cold (which is why it is disconcerting at markets and megalomarts in Australia and elsewhere to see melons sliced in half, wrapped in plastic and sitting at ambient temperature, which can be a tad warm in Brisbane).

A new study compared two cantaloupe cutting methods and concluded that it’s best to limit contact with pathogens on the farm.

Whole and cut cantaloupes have been implicated as vehicles in foodborne illness outbreaks of norovirus, salmonellosis, and listeriosis. Preparation methods that minimize pathogen transfer from external surfaces to the edible tissue are needed.

Two preparation methods were compared for the transfer of Listeria monocytogenes, Salmonella enterica serovar Typhimurium LT2, murine norovirus, and Tulane virus from inoculated cantaloupe rinds to edible tissueand preparation surfaces.

For the first method, cantaloupes were cut into eighths, and edible tissue was separated from the rind and cubed with the same knife used to open the cantaloupes. For the second method, cantaloupes were scored with a knife around the circumference sufficient to allow manual separation of the cantaloupes into halves. Edible tissue was scooped with a spoon and did not contact the preparation surface touched by the rind. Bacteria and virus were recovered from the rinds, preparation surfaces, and edible tissue and enumerated by culture methods and reverse transcription, quantitative PCR, respectively. Standard plate counts were determined throughout refrigerated storage of cantaloupe tissue.

Cut method 2 yielded approximately 1 log lower recovery of L. monocytogenes and Salmonella Typhimurium from edible tissue, depending on the medium in which the bacteria were inoculated. A slight reduction was observed in murine norovirus recovered from edible tissue by cut method 2. The Tulane virus was detected in approximately half of the sampled cantaloupe tissue and only at very low levels. Aerobic mesophilic colony counts were lower through day 6 of storage for buffered peptone water–inoculated cantaloupes prepared by cut method 2. No differences were observed in environmental contamination as a function of cutting method.

Although small reductions in contamination of edible tissue were observed for cut method 2, the extent of microbial transfer underscores the importance of preventing contamination of whole cantaloupes.

Transfer of pathogens from cantaloupe rind to preparation surfaces and edible tissue as a function of cutting method

Journal of Food Protection®, Number 5, May 2016, pp. 696-889, pp. 764-770(7)

Shearer, Adrienne E. H.; LeStrange, Kyle; Castañeda Saldaña, Rafael; Kniel, Kalmia E.

Listeria recalls in frozen produce raises questions about source

With over 500 products now being recalled because they may contain frozen fruits and veggies from CRF Frozen Foods, I’m not going to keep track of them.

stahlbush.island.farmsThis one, though, is of interest because of the label: Stahlbush Island Farms – Family Grown Food.

The food recall warning issued on May 6, 2016 has been amended to correctly identify the “Best By” date for one code of the affected Stahlbush Island Farms brand Cut Green Beans.

Industry is recalling Stahlbush Island Farms brand Cut Green Beans from the marketplace due to possible Listeria monocytogenes contamination. Consumers should not consume the recalled products.

So is the family grown food firm bringing product from Washington state to Oregon?


Pathogens? In NZ milk? Never …

Zoonotic bacteria such as Campylobacter, Listeria, and Shiga toxin–producing Escherichia coli have been found in bulk tank milk in many countries, and the consumption of raw milk has been implicated in outbreaks of disease in New Zealand.

milk.pathogens.nzFecal contamination at milking is probably the most common source of pathogenic bacteria in bulk tank milk.

Raw milk was collected from 80 New Zealand dairy farms during 2011 and 2012 and tested periodically for Campylobacter, E. coli O157, Listeria monocytogenes, and Salmonella. Milk quality data such as coliform counts, total bacterial counts, and somatic cell counts also were collected. By treating the total bacterial count as a proxy for fecal contamination of milk and utilizing farm and animal level prevalence and shedding rates of each pathogen, a predictive model for the level of pathogenic bacteria in bulk tank raw milk was developed. The model utilizes a mixture distribution to combine the low level of contamination inherent in the milking process with isolated contamination events associated with significantly higher pathogen levels. By simulating the sampling and testing process, the predictive model was validated against the observed prevalence of each pathogen in the survey.

The predicted prevalence was similar to the observed prevalence for E. coli O157 and Salmonella, although the predicted prevalence was higher than that observed in samples tested for Campylobacter.

Estimating bacterial pathogen levels in New Zealand bulk tank milk

Journal of Food Protection®, Number 5, May 2016, pp. 696-889, pp. 771-780(10)

Marshall, J. C.; Soboleva, T. K.; Jamieson, P.; French, N. P.