Thank you, WGS: Listeria linked to smoked salmon in Denmark and France

In Denmark, on 23 August 2017, Statens Serum Institut (SSI) identified a genetic cluster of four human Listeria monocytogenes sequence type (ST) 8 isolates by core genome multilocus sequence typing (cgMLST) [1]. The allele calling was performed in BioNumerics (v7.6.2, Applied Maths, Belgium). We initiated an epidemiological investigation and notified the Danish Central Outbreak Management Group (collaboration between the Danish Veterinary and Food Administration (DVFA), the National Food Institute at the Technical University of Denmark (DTU) and SSI). On 25 August, two additional human isolates were found to belong to the same genetic cluster.

A confirmed case was defined as a person clinically diagnosed with listeriosis after 1 January 2017 with laboratory-confirmed L. monocytogenes ST8 clustering using cgMLST (≤ 5 allelic distance, single linkage). Cases diagnosed before 1 January 2017 with an isolate belonging to this cluster were defined as probable cases.

As of 25 August 2017, the genetic cluster comprised six cases; five confirmed and one probable. The age of the cases ranged from 59 to 96 years (median 80 years) and four were women. All patients had underlying illness and no travel history. One patient died within 30 days of diagnosis. Epidemiological investigations including a standard questionnaire on exposures showed that all five confirmed cases had consumed cold-smoked and/or cured salmon in the 30 days before disease onset. Four cases had bought the salmon in retail chain X. No other food-item was reported as consumed in high frequencies among cases. Epidemiological follow-up for the probable case did not include information on fish consumption.

On 29 August 2017, a comparison between the human outbreak isolates and 16 L. monocytogenes ST8 food- and environmental isolates identified in Denmark from 2014 to August 2017 showed that the human isolates clustered with a food isolate from cold-smoked salmon, cut and packaged at company Y in Poland (zero to two allelic differences using cgMLST). L. monocytogenes had been detected on 31 July 2017 at levels of 110 CFU/g (threshold: 100 CFU/g) at the end of shelf life. The product was widely sold in Denmark and had been sampled by the DVFA in retail chain X, as part of a consumer exposure survey (i.e. analyses project on retail packages). Because the L. monocytogenes concentration had been just above the accepted limit and found at the end of the product shelf life a recall of this batch was not conducted. However, due to the positive finding, follow-up sampling had been performed on the 9 and 10 August 2017 from the central storage unit of retail chain X. L. monocytogenes had been isolated from two batches analysed before end of shelf life. In one sample from the same batches, which was also analysed at the end of the shelf life, on 28 August 2017 a L. monocytogenes level of 240 CFU/g was found. Isolates from the follow-up samples had zero to four allelic differences to the human outbreak isolates using cgMLST.

The human outbreak sequences were also compared to all L. monocytogenes ST8 genomes derived from clinical samples in Denmark from 2012 onwards. Although ST8 genomes from Danish patients in the period 2012–2017 showed high diversity, the outbreak isolates clearly formed a distinct cgMLST cluster with 16 allelic differences to the nearest isolates outside the genetic outbreak cluster and a maximum of nine allelic differences within the cluster (Figure 2a). We investigated the relatedness of outbreak isolates further by single-nucleotide polymorphisms (SNP) analysis performed by both SSI and DTU using two analysis pipelines: Northern Arizona SNP Pipeline (NASP) [2] and CSI Phylogeny version 1.4 from Center for Genomics Epidemiology (CGE), DTU [3] leading to the same conclusion.

On 30 August 2017, DVFA advised retail chain X to recall all cold-smoked salmon produced at company Y. This advice was based on the elevated number of L. monocytogenes (240 CFU/g) found in the product at the end of shelf-life and the link to the outbreak. Retail chain X voluntarily recalled both cold-smoked and cured salmon produced at company Y. As part of the recall procedure, retail chain X informed company Y on the situation. Information from company Y, provided by the Polish food authorities via the European Union Rapid Alert System for Food and Feed (RASFF), showed that the implicated batches were exclusively sold via retail chain X and only in Denmark.

The French National Reference Centre (NRC) for Listeria (Institut Pasteur, Paris), compared the sequences of the Danish human isolates against its database, using cgMLST as previously described [1,4]. A human isolate from a French resident belonged to the same cluster (L2-SL8-ST8-CT771) as the Danish isolates. This French probable case, a female patient in her mid-80s, was diagnosed in June 2016. Epidemiological investigations carried out by Santé Publique France were inconclusive, since food consumption history was not available at the time of diagnosis nor could information on travel to Denmark be retrieved, as the person had since died.

On 6 September 2017, an official control by the Ministry of Economy was carried out at a French retailer where a kosher chilled cured salmon was sampled for analysis. The sample was contaminated with L. monocytogenes at the level of 460 CFU/g and the salmon producer was company Y. An isolate was sent to the French NRC for typing and showed to belong to the same cgMLST type as the Danish outbreak. Further investigations on the food product confirmed that it had not been further processed after production in Poland. The product was recalled and no human cases were linked to its consumption as of beginning of December 2017.

The other nine countries that replied to the EPIS-FWD UI-426 notification (Austria, Finland, Germany, Luxembourg, the Netherlands, Norway, Slovenia, Sweden, United Kingdom) did not report any human or food isolates linked to the Danish outbreak. However, after submission of this report, at the end of November, we were informed through EPIS about three genetically linked human isolates in Germany.

Discussion

Here we report on a listeriosis outbreak and highlight the value of rapidly comparing the genomes of human and food/environmental isolates at the national and international levels.

The fact that the contaminated salmon products identified in Denmark and France were from different batches suggests environmental contamination possibly at the production facility at company Y. It is too early to assess whether any measures taken at company Y have been effective in controlling the outbreak. However, experiences from previous investigations suggest that once L. monocytogenes is detected in one product, the whole production site should be subject to a thorough inspection, and sampling with special attention to all the possible contamination/cross contamination issues before implementing corrective measures [5,6]. Moreover, the risk for L. monocytogenes persistent strains in the production environment requires the close monitoring for several years to ensure the elimination of these [7,8].

Since WGS was introduced for routine surveillance in Denmark, a number of listeriosis outbreaks have been detected and solved, including outbreaks involving cold-smoked ready-to-eat sliced fish products [5]. The present investigation further reinforces the suspicion that ready-to-eat fish products are important sources of L. monocytogenes infections in Denmark, as well as in other countries.

Though only involving a low number of isolates, WGS L. monocytogenes surveillance and communication between countries allowed us to detect and rapidly solve this salmon-associated outbreak, leading to food product recall in two European countries. Compared with previous typing methods, WGS has a higher discriminatory power and the ability to determine genetic distance between isolates. The introduction of WGS for surveillance of food-borne infections has shown that it improves outbreak detection and facilitates outbreak investigations and likely helps reduce the number of infections [4,9-16]. The EPIS-FWD communication platforms allowed for the communication to link cases across borders. However, currently cross-border outbreaks are only detected when case numbers in at least one country exceed normal levels and are notified internationally. Therefore, a possible future system for easy exchange of and comparison of WGS data, e.g. by the use of an agreed cgMLST nomenclature, across borders will enable the identification of more dispersed outbreaks as well as cross-border links between food samples and human infections. This report highlights that by the application of cross-disciplinary and real-time cross-border comparison of WGS data, L. monocytogenes infections can be prevented and thereby providing safer food for at-risk groups such as the elderly, immunodeficient individuals and pregnant women.

Cross-border outbreak of listeriosis caused by cold-smoked salmon, revealed by integrated surveillance and whole genome sequencing (WGS), Denmark and France, 2015 to 2017

Schjørring Susanne, Gillesberg Lassen Sofie , Jensen Tenna, Moura Alexandra, Kjeldgaard Jette S, Müller Luise, Thielke Stine, Leclercq Alexandre, Maury Mylene M, Tourdjman Mathieu, Donguy Marie-Pierre, Lecuit Marc, Ethelberg Steen, Nielsen Eva M. Cross-border outbreak of listeriosis caused by cold-smoked salmon, revealed by integrated surveillance and whole genome sequencing (WGS), Denmark and France, 2015 to 2017. Euro Surveill. 2017;22(50):pii=17-00762. https://doi.org/10.2807/1560-7917.ES.2017.22.50.17-00762

https://eurosurveillance.org/content/10.2807/1560-7917.ES.2017.22.50.17-00762

EU Listeria-in-frozen veg outbreak hits Australia

The Listeria-in-frozen veg outbreak in the EU that has killed nine and sickened 47 since 2015 has taken an Australian twist: the vegetables distributed by Belgium-based frozen food distributor Greenyard Frozen NV were also distributed in Australia (and who knows where else) underlying the role of bullshit and faith regarding global food safety.

Food safety is, of course, any distributor’s first priority (as Sorenne asked me today, about something completely different, “was that sarcasm?”

Nothing funny about this.

A whole bunch of frozen veg stocked by Woolworths, IGA and ALDI in Australia have been added to the recall by Food Standards Australia New Zealand (FSANZ).

FSANZ spokeswoman Lorraine Haase said there had not been any evidence of infections in Australia, but a number of people had died in the United Kingdom.

Two days later, on July 11, 2018, the Victorian Department of Health and Human Services identified a case of Listeria from earlier in 2018 that has now been linked to the strain in Europe which has led to a recall of a range of imported frozen vegetables.

The listeria is the same serotype with similar genetics.

Unfortunately, the Victorian case who was being treated for another serious illness died earlier this year.

So it is not possible to confirm whether this person actually consumed any of the frozen vegetable products.

This is not the same serotype of Listeria which killed seven in Australia and caused one miscarriage after consumption of rockmelon earlier this year.

Listeria can be anywhere, and it is up to food producers and merchants to provide rapid, reliable, relevant and repeated information about these outbreaks, which, based on conversation at a hockey tournament in New South Wales this weekend, are starting to permeate the consciousness of shoppers in Aus.

9 dead, 38 sick from Listeria linked to frozen corn in EU back to 2015

My daughters ate a lot of frozen peas and corn when they were young.

Now I’m being told by Europeans I’m stupid.

As I’ve written before, Chapman and I did a bunch of work with the processing vegetable growers in Ontario (that’s in Canada).

We didn’t do any testing, but all the plants we visited had internal Listeria testing and used test-and-hold procedures. That was over 15 years ago.

Additionally, the blanching process should have removed Listeria (but should be verified).

The UK Food Standards Agency, Food Standards Scotland, Public Health England and Health Protection Scotland – that’s a lot of admin types — are reminding people that most frozen vegetables, including sweetcorn, need to be cooked before eating. This includes if adding them to salads, smoothies or dips.

People should always follow manufacturers’ instructions when preparing their food. If the product is not labelled as “ready to eat”, the cooking instructions should always be followed before eating the food hot or cold. 

In the UK, that means piping hot mush.

Any barfbloggers in the EU wanna take a picture of those clear cooking instructions on frozen corn and send them on?

Last week, the European Food Safety Authority said that frozen corn and possibly other frozen vegetables are the likely source of an outbreak of Listeria monocytogenes that has been affecting Austria, Denmark, Finland, Sweden, and the United Kingdom since 2015.

Experts used whole genome sequencing to identify the food source, which initially was thought to be limited to frozen corn. As of 8 June 2018, 47 cases including nine deaths had been reported.

The same strains of L. monocytogenes have been detected in frozen vegetables produced by the same Hungarian company in 2016, 2017 and 2018. This suggests that the strains have persisted in the processing plant despite the cleaning and disinfection procedures that were carried out.

The available information confirms the contamination at the Hungarian plant. However, further investigations, including thorough sampling and testing, are needed to identify the exact points of environmental contamination at the Hungarian plant. The same recommendation applies to other companies belonging to the same commercial group if environmental contamination is detected.

On 29 June 2018, the Hungarian Food Chain Safety Office banned the marketing of all frozen vegetable and frozen mixed vegetable products produced by the affected plant between August 2016 and June 2018, and ordered their immediate withdrawal and recall. This last measure is likely to significantly reduce the risk of human infections and contain the outbreak. All freezing activity at the plant has been stopped.

New cases could still emerge due to the long incubation period of listeriosis (up to 70 days); the long shelf-life of frozen corn products; and the consumption of frozen corn bought before the recalls and eaten without being cooked properly.

To reduce the risk of infection, consumers should thoroughly cook non ready-to-eat frozen vegetables, even though these products are commonly consumed without cooking (e.g. in salads and smoothies). This applies especially to consumers at highest risk of contracting listeriosis – such as the elderly, pregnant women, new-borns and adults with weakened immune systems.

Frozen fruit and veg: That’s what my 2-decade hockey buddy, who also has four Canadian kids about the same age as mine, said when I asked, how do you go about managing the food for all these kids (along with the pets and horses).

But like Hepatitis A in frozen fruit, I now cook the shit out of them.

Listeria in Goodleaf brand Daikon Radish microgreens leads to recall

Goodleaf Community Farms Ltd. is recalling Goodleaf brand Daikon Radish microgreens from the marketplace due to possible Listeria monocytogenes contamination. Consumers should not consume the recalled product described below.

Recalled products

Brand Name  Common Name        Size     Code(s) on Product  UPC

Goodleaf        Daikon Radish (microgreens)        75 g     BB/MA JN 30

LOT# MR088 6 28451 71410 1

What you should do

If you think you became sick from consuming a recalled product, call your doctor.

Check to see if you have recalled products in your home. Recalled products should be thrown out or returned to the store where they were purchased.

This recall was triggered by the company. The Canadian Food Inspection Agency (CFIA) is conducting a food safety investigation, which may lead to the recall of other products. If other high-risk products are recalled, the CFIA will notify the public through updated Food Recall Warnings.

The CFIA is verifying that industry is removing recalled product from the marketplace.

There have been no reported illnesses associated with the consumption of this product.

7 dead, 1 miscarriage: New control measures to be set up on Australian rockmelon farms

My thoughts go to Australian rockmelon growers because they’ve been sold down the stream.

In April, thousands of rockmelons were left to rot in paddocks near Geraldton on the Western Australian coast, record low prices and lost markets meant they were simply not worth picking.

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.

GPM brand pea shoots recalled due to Listeria in Canada

Pea sprouts in some restaurants have replaced mung bean and alfalfa sprouts for those who still want to serve some sort of raw sprout.

I’ve always been suspicious, I wouldn’t touch them, but in the absence of outbreaks, I guess it made sense.

Turns out they can be contaminated with Listeria.

Golden Pearl Mushrooms Ltd. is recalling GPM brand Pea Shoots from the marketplace due to possible Listeria monocytogenes contamination. Consumers should not consume the recalled products described below.

Recalled products

Brand Name  Common Name        Size     Code(s) on Product  UPC

GPM   Sweet Pea Shoots     230 g   11421  6 84469 00008 7

GPM   Pea Shoots     100 g   11421  6 84469 00012 4

GPM   Pea Shoots     455 g   11421  6 84469 00018 6

If you think you became sick from consuming a recalled product, call your doctor.

Check to see if you have recalled products in your home. Recalled products should be thrown out or returned to the store where they were purchased.

This recall was triggered by Canadian Food Inspection Agency (CFIA) test results. The CFIA is conducting a food safety investigation, which may lead to the recall of other products. If other high-risk products are recalled, the CFIA will notify the public through updated Food Recall Warnings.

There have been no reported illnesses associated with the consumption of these products.

A tale of two outbreaks: Farmers have to get ahead of the public conversation because they lose

I don’t like counting outbreak tolls or square mileage affected – in the absence of meaningful information – because it seems like accounting, and I have an accountant to do that.

Numbers numb and go past the story: Stalin said, “One death is a tragedy; one million is a statistic.”

None of us wants to be a statistic.

Whether it’s E. coli in Romaine lettuce in the U.S. or Listeria in rockmelon in Australia, producer groups have failed the farmers they are supposed to represent.

Step up. It’s a long way to the top if you want to rock and roll.

4 dead: Mashed potato machine thought to be source of Listeria contamination in Sweden

The Local reports there have been four deaths in Västra Götaland, in western Sweden, that experts have linked to listeria bacteria. 

Experts at the Centre for Communicable Disease Control (Smittskydd) stressed that all those who passed away were elderly people or affected by other illnesses. 

In other words, they said it was impossible to confirm that listeriosis, the disease caused by listeria bacteria, was responsible for the deaths. 

But the group behind the meals and the local region are not taking any chances, issuing a recall for potentially contaminated products across the region. 

The group behind the products, Food Company, released a statement with information about the items that were affected and their expiration dates. 

The items have an expiration date between May 16th and 25th.

All items – single portion, pre-cooked and chilled packet meals – contained mashed potatoes, with the company explaining that the machine that made the mash was responsible for the bacteria outbreak. 

It added that the machine has since been removed from the production factory.

The deli is not safer: Slicer cleaning and Listeria

The Centers for Disease Control and Prevention (CDC) estimates that 3,000 people die in the United States each year from foodborne illness, and Listeria monocytogenes causes the third highest number of deaths. Risk assessment data indicate that L. monocytogenes contamination of particularly delicatessen meats sliced at retail is a significant contributor to human listeriosis. Mechanical deli slicers are a major source of L. monocytogenes cross-contamination and growth.

In an attempt to prevent pathogen cross-contamination and growth, the U.S. Food and Drug Administration (FDA) created guidance to promote good slicer cleaning and inspection practices. The CDC’s Environmental Health Specialists Network conducted a study to learn more about retail deli practices concerning these prevention strategies. The present article includes data from this study on the frequency with which retail delis met the FDA recommendation that slicers should be inspected each time they are properly cleaned (defined as disassembling, cleaning, and sanitizing the slicer every 4 h).

Data from food worker interviews in 197 randomly selected delis indicate that only 26.9% of workers (n = 53) cleaned and inspected their slicers at this frequency. Chain delis and delis that serve more than 300 customers on their busiest day were more likely to have properly cleaned and inspected slicers. Data also were collected on the frequency with which delis met the FDA Food Code provision that slicers should be undamaged. Data from observations of 685 slicers in 298 delis indicate that only 37.9% of delis (n = 113) had slicers that were undamaged. Chain delis and delis that provide worker training were more likely to have slicers with no damage.

To improve slicer practices, food safety programs and the retail food industry may wish to focus on worker training and to focus interventions on independent and smaller delis, given that these delis were less likely to properly inspect their slicers and to have undamaged slicers.

Retail deli slicer inspection practices: An EHS-Net study, May 2018

LAUREN E. LIPCSEI,1* LAURA G. BROWN,1 E. RICKAMER HOOVER,1 BRENDA V. FAW,2 NICOLE HEDEEN,3 BAILEY MATIS,4DAVID NICHOLAS,5 and DANNY RIPLEY6

Journal of Food Protection, vol. 81 no. 5

https://doi.org/10.4315/0362-028X.JFP-17-407

http://jfoodprotection.org/doi/abs/10.4315/0362-028X.JFP-17-407?code=fopr-site

People barfing: Listeria in Deli Classic brand Seasoned Cooked Roast Beef Round in Canada

There was this one time, about 5 years ago, and I had to go to emergency to get 13 stiches after falling while trying to teach Sorenne to ride a bicycle, and Dr. Monty Python said, “merely a flesh wound.”

I was back 8 hours later for an additional 10 stiches cause it was still bleeding.

According to the Canadian Food Inspection Agency there have been reported illnesses associated with a product similar to Erie Meat Products Ltd. Deli Classic brand Seasoned Cooked Roast Beef Round however, at this time, there have been no confirmed illnesses associated with the product identified in this Food Recall Warning.

Uh-huh.

The Canadians are like their Commonwealth breathen, the Australians, in that the food regulators leave it up to the heath regulators to say if someone is sick from food.

At least in Canada the food types will say if someone is sick, whereas the Australian food types say, nothing to see here, move along.

But, Canadian regulatory types refuse to say how many are sick, leaving that to the health folks: shouldn’t a government be able to deliver a clear, consistent message?