• Posted: May 4th, 2011 - 10:50am by Doug Powell

    The risk may be small, but the failures are tragic.

    Governments routinely warn that immunocompromised people, including expectant mothers and the elderly, should refrain from certain ready-to-eat refrigerated foods like deli meats and smoked salmon because of the risk of listeriosis.

    Elizabeth Weise writes in today’s USA Today that the U.S. Centers for Disease Control and Prevention has been saying for at least 11 years now that people over 50 and especially those over 65 should avoid hot dogs, lunch meats, cold cuts and other deli meats unless they are reheated to 165 degrees — "steaming hot" in CDC's words.

    The government also says you shouldn't keep an open package of sliced deli meat more than five days, all to reduce the risk of infection from a bacteria called listeria. But some question whether the country's been paying attention.

    Barbara Resnick, incoming president of the American Geriatrics Society and a professor of nursing at the University of Maryland, knows of no one over that age who heats deli meats to that level and says she's never seen a case of listeriosis in a patient.

    Neil Gaffney, spokesman for the U.S. Department of Agriculture's Food Safety Inspection Service said, "When it comes to food safety, we're serious: People at risk for listeriosis should not eat hot dogs, luncheon meats or deli meats unless they are reheated until steaming hot. Thoroughly reheating food can help kill any bacteria that might be present. If you cannot reheat these foods, do not eat them."

    Mike Doyle, a professor of food microbiology at the University of Georgia said about 85% of listeriosis cases are linked to cold cuts or deli meats, and that today almost all packaged lunch meats contain either added sodium lactate, an acid formed by fermentation, or potassium lactate, fermented from sugar, as antimicrobials. That's what he looks for when he buys cold cuts.

    And based on FSIS risk-assessment data, meats sliced at the store pose a greater risk than meats pre-sliced at federally inspected establishments

    Listeria and cold cuts were ranked just last week as the third worst combination of a food and a pathogen in terms of the burden they place on public health, costing $1.1 billion a year in medical costs and lost work days, according to a study by the University of Florida's Emerging Pathogen Institute.

    Douglas Powell a professor of food safety at Kansas State University, said, "And you can't see, taste or smell that it's there.”

    CDC also says don't keep opened packages of lunch meat, or meat sliced at the local deli, for longer than three to five days. That's another one no one pays attention to, says Kansas' Powell.

    "Anecdotally, lots of people keep cold cuts in their refrigerator far longer than they should. People keep them for one to two weeks. That's the key message. If you get it from the deli counter, four days max."

    What wasn’t included in the story is evidence of listeria-related tragedies in other countries – countries that may not have approved those listeria-restraining additives.

    Twenty-three elderly people died in Canada in 2008 after eating listeria-laden cold-cuts from Maple Leaf Foods. Later that year, listeria in soft cheese in Quebec led to 38 hospitalizations, of which 13 were pregnant and gave birth prematurely. Two adults died and there were 13 perinatal deaths.

    The New South Wales Food Authority said last month the Authority provides information on listeria to pregnant women to allow them to make an informed food choice regarding the risk and how to minimize it. It is not to say that every piece of deli meat has Listeria on it, but some foods have a higher potential rate of contamination than others, and it is better to avoid them.

    The risk of acquiring listeriosis is low. However the consequences for a pregnant woman contracting listeriosis are dire.

    While the Authority may be accused of ‘being over the top’, we may also be accused of neglecting pregnant women if we did not provide this information so pregnant women could make informed choices in what they eat.

    Over the last 5 years in Australia there have been between 4 and 14 cases of listeriosis diagnosed in pregnant women or their babies each year. These infections have resulted in the deaths of 8 fetuses or newborn babies.

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  • Posted: April 20th, 2011 - 10:24am by Doug Powell


    Giving food safety – or any – advice to pregnant women is fraught with angst. And probably a lot of hypocrisy if you’re a dude.

    I don’t want to freak anyone out, especially expectant mothers, but also have a responsibility to share accurate, evidence-based information if I know something about, say, food safety.

    The certainties of youth left me long ago.

    But certainties were on full display in an article distributed by the Australian Associated Press on April19, 2011, entitled, Pregnancy diet overkill.

    Among the nosestretchers offered up by dietician and author Tara Diversi, quoted in the AAP story (I'll put quotes from Tara or the story in italics, with a bullet, and my responses in something other than italics; and the comments at the bottom from NSW Food Authority will be in italics):

    • "It's not that you're at higher risk (of food poisoning) being pregnant."

    No. A Dec. 2007 review of listeria in pregnancy states,

“One of the most important changes during pregnancy is the down-regulation of the cellular immune system. Because the fetus is genetically different from the mother, the body treats it as a graft. To prevent the maternal immune system from rejecting the fetus, cell-mediated immunity must therefore be suppressed during pregnancy. This is favored by high levels of progesterone. However, reduced cell-mediated immune function leads to increased susceptibility of the woman and her fetus to infections by intracellular pathogens such as Listeria monocytogenes. That is why pregnant women are 20 times more at risk of contracting listeriosis than are other healthy adults. Pregnant women account for 30% of all cases of listeriosis and 60% of cases among persons 10 to 40 years of age.

“Typically, systemic infection occurs most frequently after ingestion of food contaminated with L monocytogenes. The bacteria cross the mucosal barrier of the intestine, probably aided by active endocytosis of organisms by epithelial cells. Once in the bloodstream, bacteria spread to different sites, but they have a particular affinity for the central nervous system or placenta. While circulating, the bacteria are internalized by macrophages and other plasma cells and are thereafter spread cell-to-cell through phagocytosis. As a result, antibodies, complement, and neutrophils become unable to protect the host.”

    Pregnant women are about 20 times more likely than other healthy adults to get listeriosis. About a third of all reported cases in Illinois happen during pregnancy. Infection during pregnancy may result in spontaneous abortion during the second and third trimesters, or stillbirth.

    The advice from the U.S. Centers for Disease Control is clear: Do not eat hot dogs, luncheon meats, or deli meats, unless they are reheated.

    It has been documented that many pregnant women are not aware of the risks associated with consuming refrigerated, ready-to-eat foods like cold cuts.

    Researchers reported in the Australian and New Zealand Journal of Health that in a survey of 586 women attending antenatal clinics in one private and two major public hospitals in New South Wales between April and November 2006, more than half received no information on preventing Listeria.

    • But who would have thought the humble alfalfa sprout could be a cold-blooded killer in disguise?

    Outbreaks of foodborne illness related to raw sprouts happen frequently. A table of North American raw sprout-related outbreaks is available at

    • Diversi says there hasn't been a reported incident of poisoning from undercooked eggs since 1970s. "(Some of the advice) is weird. It's not like we're a Third World country," she says.

    No. Hundreds of people have been sickened in Australia in the past five years from consuming undercooked eggs or dishes containing raw eggs, including 111 sick with salmonella from home-made aioli -- a garlic mayonnaise that includes raw egg – at the Burger Barn in Albury, Australia last year. Other Australian outbreaks are available at these links.


    • "It's hard, because as a dietitian you don't want to give blanket advice. But if I were pregnant myself I would eat poached eggs and I would eat from salad bars and I would eat lean meats because I know that they're going to give me energy and the likelihood of getting food poisoning from it is relatively low. The trick is to limit the risks by buying your lunch from a reputable place with a high turnover.”

    No. This sounds suspiciously like the terrible and libelous advice issued by the Motherisk team last year at Toronto’s Hospital for Sick Children, in which they stated,

    “pregnant women need not avoid soft-ripened cheeses or deli meats, so long as they are consumed in moderation and obtained from reputable stores.”

    I have no idea what a reputable source is. Certainly doesn’t have anything to do with microbiology.

    Fortunately, the folks in Sydney at the New South Wales Food Authority comprehend some risk communication basics and fired out their response within a day. Excerpts below:

    In its role as Australia’s first and only through-chain food regulatory agency the NSW Food Authority is responsible for providing consumers with safer food and clearer choices.

    The Authority maintains a segment on its website dedicated to pregnancy and food safety.

    It clearly states the best way to meet you and your baby's nutritional needs is to eat a wide variety of nutritious foods.

    These should include:
    • bread, cereals, rice, pasta & noodles preferably wholegrain or wholemeal
    • vegetables & legumes
    • fruit
    • milk, yoghurt, hard cheese preferably low fat
    • meat, fish, poultry, cooked eggs & nuts.

    The Authority provides information about how best to enjoy those foods safely, what foods to avoid during pregnancy and provides alternatives to foods identified as having a higher risk of containing certain bacteria that could be harmful to pregnant women and their unborn babies.

    The Authority provides information on Listeria to pregnant women to allow them to make an informed food choice regarding the risk and how to minimise it. It is not to say that every piece of deli meat has Listeria on it, but some foods have a higher potential rate of contamination than others, and it is better to avoid them.

    The risk of acquiring listeriosis is low. However the consequences for a pregnant woman contracting listeriosis are dire.

    While the Authority may be accused of ‘being over the top’, we may also be accused of neglecting pregnant women if we did not provide this information so pregnant women could make informed choices in what they eat.

    Over the last 5 years in Australia there have been between 4 and 14 cases of listeriosis diagnosed in pregnant women or their babies each year. These infections have resulted in the deaths of 8 foetuses or newborn babies.

    Rates of listeriosis are increasing in Europe including France where they have increased over the last five years.

    Listeriosis rates in France are twice that of Australia.

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  • Posted: April 7th, 2011 - 12:38pm by Doug Powell

    In Aug. 2010, Veron Foods, LLC of Prairieville, La. recalled approximately 500,000 pounds of “ready to eat” sausage and hog head cheese products that ‘may have been’ contaminated with Listeria monocytogenes.

    The problem was discovered through a foodborne illness investigation that resulted in a product sample testing positive for Listeria monocytogenes, but, like crappy food safety agencies here and there, the Louisiana types wouldn’t say how many got sick.

    And everyone went back to sleep.

    Until today, when the U.S. Centers for Disease Control issued its report about an outbreak of listeria associated with eating hog head cheese in Louisiana in 2010.

    I’m guessing it was the same outbreak.

    During January--June 2010, a total of 14 cases of laboratory-confirmed invasive listeriosis were reported to the Louisiana Office of Public Health (OPH). Isolates of Listeria monocytogenes from the blood samples of eight patients were identified as serotype 1/2a and had pulsed-field gel electrophoresis (PFGE) pattern combinations that were indistinguishable from one another. …

    In-depth epidemiologic and environmental investigations of the cluster were initiated on July 26, including food history interviews of four patients. Three patients reported eating hog head cheese (a meat jelly made from swine heads and feet); the product was purchased at two grocery stores in Louisiana. A traceback investigation determined that a single brand of hog head cheese was common between the two grocery stores. L. monocytogenes serotype 1/2a was cultured from one of three product samples and from two of 16 environmental samples collected by LDAF at the processing establishment; the product and one of the two environmental samples yielded isolates with PFGE pattern combinations that were indistinguishable from the patient isolates. On August 14, LDAF coordinated a voluntary recall of approximately 500,000 pounds of hog head cheese and sausage because of possible contamination with L. monocytogenes.

    This is the first published report of an invasive listeriosis outbreak associated with hog head cheese, which is a ready-to-eat (RTE) meat. USDA-FSIS has a "zero tolerance" policy for L. monocytogenes contamination of RTE food products (1), requesting recall of such products at any detectable level of L. monocytogenes contamination. LDAF imposes and enforces equivalent requirements in state-inspected establishments.

    Louisiana OPH epidemiologists noted that 14 cases of invasive listeriosis had been reported during January--June 2010, which exceeded the state's average of five cases reported during each January--June period during the previous 3 years. For this investigation, a cluster-associated case was defined as isolation of L. monocytogenes serotype 1/2a from a normally sterile site (e.g., blood or cerebrospinal fluid) or from placental or fetal tissue (in the setting of miscarriage or stillbirth) since January 1, 2010, and PFGE pattern combination GX6A16.0001 and GX6A12.0001.

    Eight patients had illnesses that met the case definition. Their median age was 64 years (range: 38--93 years). Six patients were men; no patients were pregnant. Six patients had one or more underlying medical conditions (i.e., human immunodeficiency virus [HIV] infection, alcohol abuse, cancer, and diabetes mellitus). Illness onsets occurred from February 18 to June 16. Signs and symptoms included fever (n = 6 patients), altered mental status (n = 3), diarrhea (n = 3), vomiting (n = 3), and weakness (n = 2). Seven patients were hospitalized; two patients died. …

    The implicated brand of hog head cheese originated from a small, state-inspected processing establishment in Louisiana, which produces approximately 600 pounds of hog head cheese per week. This establishment was under federal inspection until January 2007. Routine FSIS microbiologic testing of products at the establishment detected L. monocytogenes contamination in October and December 2006; the company voluntarily recalled 290 pounds of hog head cheese in January 2007. Four L. monocytogenes isolates from USDA-FSIS samples collected in 2006 did not match the 2010 outbreak-related PFGE pattern combination. In addition, Listeria contamination was not detected in any of the 12 product samples collected by LDAF since 2007; analysis of routine environmental samples collected by the management of the processing establishment during January--July 2010 also did not detect Listeria. However, the outbreak strain was identified in environmental samples collected during the investigation, which was several weeks after the manufacture of the outbreak-associated products (Figure), suggesting that persistent environmental contamination in the processing establishment was responsible for product contamination and resulting illnesses.

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  • Posted: March 22nd, 2011 - 11:47am by Doug Powell

    The 2008 listeria outbreak in Canada caused by Maple Leaf deli meats that killed 23 and sickened 56 was characterized by multiple failures amongst multiple players – primarily Maple Leaf, the Canadian government, and dieticians at assisted-care facilities.

    A few journalists tried to peel back the layers of palp but were often stonewalled. Yesterday, the federal information czar chastised the department that serves the Prime Minister for shirking its duty to assist The Canadian Press with an access-to-information request seeking files on the listeriosis outbreak.

    The staff of Information Commissioner Suzanne Legault, an ombudsman for users of the access law, took more than two years to rule on the news agency’s complaint.

    The listeriosis matter dates back to an October 2008 request for all transcripts and minutes of conference calls in the previous two months on the health crisis.

    Four months later, the Privy Council Office decided the records it possessed did not fall under the request because they were handwritten notes, not formal minutes or transcripts.

    The information commissioner disagreed, and asked the PCO to process the notes.

    The handwritten notes were not released to The Canadian Press until February this year — 28 months after the original access request was made.

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  • Posted: March 12th, 2011 - 1:03pm by Doug Powell

    My fingerprints arrived in Ottawa (that’s in Canada) about a month ago for a travel-related security check. I know this because they signed when they received the package by courier.

    I checked on the status of the paperwork a week ago and was told, in doublespeak, by writing,

    “Given the information sent, the application has not reached our system at this time. Due to our quality control process, this does not mean that they are not in the building.”

    Maybe all Canadian government-types go to the same communication classes, because a couple of days ago, Health Canada issued a press release about updates to its listeria control policy.

    Health Canada has completed its update of the 2004 policy on Listeria monocytogenes in Ready-to-Eat (RTE) foods, in view of enhancing the control of Listeria in high-risk foods. The purpose of this policy is to provide guidance to stakeholders regarding verification and control, as well as regulatory oversight and compliance activities of RTE foods with respect to their potential to support the growth of Listeria monocytogenes.

    The Canadian "Policy on Listeria monocytogenes in ready-to-eat foods" (hereafter referred to as the Listeria policy) is based on Good Manufacturing Practices1 (GMPs) and the principles of HACCP (Hazard Analysis Critical Control Point). This policy was developed using a health risk assessment (HRA) approach and uses as its foundation a combination of inspection, environmental sampling and end-product testing to verify control of Listeria monocytogenes in ready-to-eat (RTE) foods. Focus is given to environmental verification and control, especially in post-lethality areas, as applicable. This policy applies to RTE food sold in Canada, produced both domestically and imported. The present policy revises and replaces the Policy on Listeria monocytogenes in ready-to-eat foods dated October 4, 2004.

    How this will mean fewer sick and dead people, like the 23 who died in the 2008 Maple Leaf listeria mess, is not addressed. However the Health Canada types did say, “There is an increased focus on outreach with the federal/provincial/territorial community to increase awareness of the risks of foodborne listeriosis and to provide guidance on how to reduce the risks of acquiring listeriosis to personnel in institutions where high-risk people may be exposed.”

    How this outreach will be conducted and evaluated is not discussed. No mention of labels or public availability of testing data. But read it yourself and decide.

    But when I tried to read the original I had to submit a request, and received the following:

    “Thank you for contacting Health Canada. Your message has been received. We will get back to you as soon as possible.”

    The document eventually arrived.

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  • Posted: January 31st, 2011 - 11:54am by Doug Powell

    Focusing on the language needs of expectant mothers and enhancing food safety in hospitals could reduce cases of foodborne illness caused by listeria.

    Australian researchers report in the current Epidemiology and Infection that of 136 cases of listeriosis in Australia between Nov. 2001 and Dec. 2004, 40 per cent of cases with prior hospitalization were exposed to high-risk foods during hospitalization; consumption of camembert cheese was an additional risk factor.

    Of the 19 perinatal cases -- defined as illness in a pregnant woman, fetal loss, or illness in a baby aged less than 3 months with isolation of L. monocytogenes from at least one of the maternofetal pair -- living in a household where a language other than English (LOTE) was spoken was the primary risk factor associated with listeriosis.

    The numbers are small, but the researchers have identified a persistent problem – providing information is nice, but what if the target can’t read or understand (in this case) English?

    “The Food Standards Australia and New Zealand (FSANZ) website only provides a brochure on listeriosis and food in English. Languages used in State and Territory brochures vary widely with some only including English while others provide up to 14 languages other than English.

    “This study identified that listeriosis prevention messages need to be disseminated in multiple languages and primary-care practitioners should ensure that patients from households speaking a LOTE receive counselling on listeriosis prevention.”

    Which sounds nice, but since hospitals are serving high-risk foods to others at risk, maybe the medical community is a limited source of information. And just because a brochure is in another language doesn’t mean anyone will read it or act upon the information. That requires far more rigorous evaluation in terms of information needs, delivery, messages and accuracy. The morons at Toronto Sick Kids hospital told moms-to-be that cold-cuts and raw fish were OK (they're not).

    As the authors conclude,

    “The effectiveness of the implementation of the new food safety programs for food service to vulnerable persons should be carefully evaluated to ensure optimal protection of this group.”

    A national case-control study of risk factors for listeriosis in Australia
    Epidemiology and Infection (2011), 139: 437-445
    C.B. Dalton, T.D. Merritt, L.E. Unicomb, M.D. Kirk, R.J. Stafford, K. Lalor and the OzFoodNet Working Group
    Listeriosis is a foodborne disease associated with significant mortality. This study attempts to identify risk factors for sporadic listeriosis in Australia. Information on underlying illnesses was obtained from cases' treating doctors and other risk factors were elicited from the patient or a surrogate. We attempted to recruit two controls per case matched on age and primary underlying immune condition. Between November 2001 and December 2004 we recruited 136 cases and 97 controls. Of perinatal cases, living in a household where a language other than English was spoken was the main risk factor associated with listeriosis (OR 11·3, 95% CI 1·5–undefined). Of non-perinatal cases we identified the following risk factors for listeriosis: prior hospitalization (OR 4·3, 95% CI 1·0–18·3), use of gastric acid inhibitors (OR 9·4, 95% CI 2·4–37·4), and consumption of camembert (OR 4·7, 95% CI 1·1–20·6). Forty percent of cases with prior hospitalization were exposed to high-risk foods during hospitalization.


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  • Posted: January 25th, 2011 - 8:20pm by Doug Powell

    This is sorta cool – unless you contract a subset of listeria and have heart problems.

    Listeria is everywhere, as Michael McCain of Maple Leaf Foods likes to remind everyone, but Nancy Freitag, from the University of Illinois, Chicago, reports in the Journal of Medical Microbiology that some listeria strains had modified surface proteins that helped target the heart.

    "A significant number - about 10% - of L. monocytogenes infections involve the heart. In these cases, death rate from cardiac illness is estimated to be up to 35%, yet very little is known about how these bacteria infect heart tissues."

    Scientists in the United States discovered that mice infected with the strains had up to 15 times more bacteria in their hearts than those exposed to other forms of listeria.

    The bug has an unusual ability to grow in low temperatures and can be found in a wide range of foods including soft cheeses, cold meat products, raw vegetables, fish, salads and unpasteurized milk.

    Pregnant women are especially susceptible to listeria, which can cause them to miscarry.

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  • Posted: January 13th, 2011 - 5:42pm by Doug Powell

    Is there anything better than herring and dill aquavit (why do you think the kid is named Sorenne, and prefers smoked salmon, olives, brie, cold cuts and pickles)?

    But there is that listeria risk.

    Ms Fish Corp of New York is recalling Ossie’s Schmaltz Herring due to Listeria monocytogenes contamination.

    The problem was discovered after routine sampling by the New York State Department of Agriculture and Markets Food Inspectors and subsequent analysis of the product by Food Laboratory personnel found the product to be positive for Listeria monocytogenes.

    Ossie’s Schmaltz Herring is packed in a 12 oz plastic container coded 2/0311. It is a product of USA. Product was distributed throughout New York State.

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  • Posted: November 20th, 2010 - 9:01am by Doug Powell

    The New York Times reports this morning that listeria can pose special challenges for artisan cheesemakers. Many make their cheese right on the farm, where the bad bacteria are right outside the cheese room door (or inside – dp). And small producers often lack the safety training and resources available at bigger companies.

    For example, Sharon McCool got a shock last year as she prepared to begin selling the first batch of cheese she had made from milk produced at her family’s organic dairy, Rosecrest Farm, in Chehalis, Wash. State inspectors told her the Swiss cheese she had labored over for months was contaminated with listeria.

    Tests showed that the bacteria was contained in a mixture of wine, water and salt, called a smear, that Ms. McCool had been brushing on her cheese each day as it aged. Without knowing it, she was dosing the cheese with listeria.

    Ms. McCool threw out 900 pounds of cheese, changed some of her practices, got rid of the smear and started over.

    Ms. McCool and her husband, Gary, have for years operated a dairy, where sanitation is paramount, so she thought she was well versed in food safety. But she now sees that she had overlooked some obvious pitfalls.

    Before, Ms. McCool said, she had been so proud of her new business that she had often showed visitors around, possibly introducing listeria through their shoes or clothing.

    Now, visitors are kept out. “Pretty much everything is really a whole lot stricter,” Ms. McCool said.

    The number of small-scale, artisan cheesemakers has boomed in recent years but little or no formal training is required. Safety rules and enforcement also vary from state to state.

    Soft cheeses — including brie, mozzarella and queso fresco — are more likely to become contaminated with listeria because they have a relatively high moisture content and low acidity, creating a more hospitable environment for the bacteria. In addition, listeria grows well at low temperatures, so even it can thrive even in a refrigerator.

    The F.D.A. said it is inspecting both raw-milk and pasteurized cheese facilities for listeria, and recalls this year have been for both types of cheeses.

    The agency also said it was reviewing the aging rules in light of evidence that the 60-day period might not be effective.

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  • Posted: November 3rd, 2010 - 12:56pm by Doug Powell

    When state regulators closed SanGar Fresh Cut Produce of San Antonio after linking the plant with four, maybe five deaths due to listeria, on Oct. 20, 2010, Sangar President Kenneth Sanquist Jr. said in a statement,

    “The state's claim that some of our produce now fails to meet health standards directly contradicts independent testing that was conducted on the same products. This independent testing shows our produce to be absolutely safe, and we are aggressively fighting the state's erroneous findings.”

    The U.S. Food and Drug Administration announced this morning they found the same listeria at the facility, matching testing done by the Texas Department of State Health Services at SanGar.

    The tests found listeria bacteria in multiple locations in the plant.

    Messages left for an attorney for SanGar by The Associated Press were not immediately returned.

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