The apparent international rise in foodborne virus outbreaks attributed to fresh produce and the increasing importance of fresh produce in the Australian diet has led to the requirement to gather information to inform the development of risk management strategies.
A prevalence survey for norovirus (NoV) and hepatitis A virus (HAV) in fresh Australian produce (leafy greens, strawberries and blueberries) at retail was undertaken during 2013–2014 and data used to develop a risk profile. The prevalence of HAV in berries and leafy greens was estimated to be <2%, with no virus detected in produce during the yearlong survey. The prevalence of NoV in fresh strawberries and blueberries was also estimated to be <2% with no virus detected in berries, whilst for leafy greens the NoV prevalence was 2.2%.
Prevalence of a bacterial hygiene indicator, Escherichia coli, was also investigated and found to range from <1% in berries to 10.7% in leafy greens. None of the NoV positive leafy green samples tested positive for E. coli, indicating it is a poor indicator for viral risk.
The risk was evaluated using standard codex procedures and the Risk Ranger tool. Taking all data into account, including the hazard dose and severity, probability of exposure, probability of infective dose and available epidemiological data, the risk of HAV and NoV foodborne illness associated with fresh Australian berries (strawberries and blueberries) sold as packaged product was deemed to be low. The risk of foodborne illness from HAV associated with leafy greens was also deemed to be low, but higher than that for fresh berries, due mainly to the potential for recontamination post-processing if sold loose. The risk of foodborne illness from NoV associated with leafy greens was deemed to be low/moderate. Despite the prevalence of NoV in leafy greens being low and the inability to discriminate between infective and non-infective virus using PCR based methodologies, the fact that NoV was detected resulted in a higher risk associated with this pathogen-product pairing; compounded by the higher prevalence of NoV within the community compared to HAV, and the potential for leafy greens to become contaminated following processing if sold loose.
Estimating risk associated with human norovirus and hepatitis A virus in fresh Australian leafy greens and berries at retail 26 August 2019
I revealed last week I was nervous about doing a media interview, because I’ve been out of the game for a while, and my brain, just don’t work so well.
Fell again today and it hurt.
I have no balance.
But I still have a brain.
So when a U.S. reporter agrees to chat at 4 a.m. EST (6 p.m. EST) I say sure, because I’ve always been a media whore. How else to spread the message.
I particularily like the lede.
Kate Bernot of The Take Out wrote, “If you ask anyone in food safety, ‘What is the one food you will not eat?’ Raw sprouts tops the list, always.”
That’s one of the first sentences out of the mouth of Doug Powell, a former professor of food safety and the publisher of barfblog, a frequently updated site that publishes evidence-based opinions on food safety.
I’ve asked him whether food-safety fears about sprouts—those tiny, crunchy squiggles in your salad or sandwich—are well-founded. He tells me the public isn’t concerned enough about them.
“Risk is inherent in the nature of the product which is why Walmart and Costco got rid of them,” he says. (Kroger also stopped selling sprouts in 2012.) “This is not a new problem. It’s been going on for decades.”
According to a paper he and three colleagues published in the journal Food Control in 2012, sprouts have been responsible for at least 55 documented foodborne outbreaks affecting more than 15,000 people globally in the past two decades. The Food And Drug Administration tallies 46 reported outbreaks of foodborne illness in the United States linked to sprouts between 1996 and 2016, accounting for for 2,474 illnesses, 187 hospitalizations, and three deaths. In an effort to reduce these outbreaks, the FDA in 2017 collected 825 samples of sprouts from across the U.S.; 14 of those tested positive for E. coli, listeria, or salmonella.
The first reason sprouts—whether alfalfa or mung bean or radish or other varieties—can carry E. coli or salmonella bacteria has to do with how the sprouts are produced. The conditions that cause a seed to sprout are the same conditions that cause bacteria to breed: warm, moist air.
“The sprout is made from germinating seeds and the seeds themselves may be the source of the contamination. When you’re germinating a seed and growing a sprout, you’re providing conditions for the sprout growth that are ideal also for bacterial growth,” says Craig Hedberg, a professor in the School Of Public Health at University Of Minnesota. “This is a product that went through incubator-like circumstances.”
The second reason is related to how most of us consume sprouts: raw. Because we value sprouts’ crunch, we rarely cook them before adding them to a dish. Powell notes that people in many Southeast Asian countries do blanch their sprouts before cooking with them, but that the West tends to consume them raw.
“The seeds can get contaminated as they’re growing, so the contamination can be internal,” Powell tells me. “So you’re never going to wash it off.”
Sprouts do have their defenders, though, who note higher levels of soluble fiber, antioxidants, vitamins, and mineral bioavailability compared to non-sprouted grains and vegetables. The Academy Of Nutrition And Dietetics statesthat “in general, the health benefits associated with savoring raw or lightly cooked sprouts outweigh risks for healthy individuals. However, be aware that there is risk of food poisoning if you plan to eat them.”
The FDA recommends cooking sprouts thoroughly to kill bacteria, and further advises that the elderly, children, people who are pregnant, and people with compromised immune systems should not eat sprouts at all. To further reduce your risk of sprout-related foodborne illness, the FDA says consumers can “request that raw sprouts not be added to your food.” So, bottom line, if you’re concerned—yeah, just don’t eat them. May we suggest beet slivers or carrot ribbons for crunch?
After germination, the highest content of isoflavonoids was observed in the clover and chickpea sprouts, which amounted to 1.1 g/100 g dw., whereas the lactic acid fermentation allowed the increase to as much as 5.5 g/100 g dw. The most beneficial properties were shown by fermented chickpea sprouts germinated in blue light.
During fermentation the number of lactic acid bacteria increased by 2 Log10CFU/mL (LU), whereas mold decreased by 1 LU, E.coli and Klebsiella sp. by 2 LU, Salmonella sp. and Shigella sp did not occur after fermentation, similar to Staphylococcus epidermidis, while S. aureus and S. saprophyticus decreased by 3 LU and in some trials were not detected.
Lactic acid fermentation of legume seed sprouts as a method of increasing the content of isoflavones and reducing microbial contamination
Providing consumers with recommendations on specific food safety practices may be a cost-effective policy option, acting either as a complement to or substitute for additional food safety regulations on food suppliers, but it would require a detailed understanding of consumer food safety practices.
Using data from the 2014 to 2016 American Time Use Survey–Eating and Health Module, we examine two food safety practices in which Government health and safety officials, as well as the broader food safety community, have offered unequivocal advice: meal preparers should always use a thermometer to verify that meat has reached a recommended temperature and consumers should avoid raw (unpasteurized) milk.
We found that 2 percent of at-home meal preparers in the United States served raw milk during a typical week; of which 80 percent lived with two or more people, 44 percent were married, 36 percent lived with one or more children, and 28 percent lived with at least one person age 62 or older, indicating the potential that at-risk populations are consuming raw milk.
While preparing meals with meat, poultry, or seafood, 14 percent of at-home meal preparers in the United States used a food thermometer. Meal preparers who use a food thermometer typically earned more, reported better physical health, were more likely to exercise, were more likely married, and had larger and younger households. Last, rates of food thermometer usage were higher for at-home meal preparers whose occupation was food-preparation related, suggesting food safety training or awareness at work may influence food safety behavior at home.
Consumer Food Safety Practices: Raw Milk Consumption and Food Thermometer Use
Rhodes, Taylor M., Fred Kuchler, Ket McClelland, and Karen S. Hamrick.
EIB-205, U.S. Department of Agriculture, Economic Research Service, January 2019.
Nontyphoidal Salmonella is a main cause of bacterial food-borne infection in Europe [1,2]. The majority of human infections is caused by a limited number of Salmonella serotypes among the 2,600 described to date [3,4]. Salmonella enterica serotype Dublin (S. Dublin) is particularly invasive in humans and more often leads to severe disease and higher mortality rates compared with other serotypes [4–7]. S. Dublin is host-adapted to bovines and is frequently isolated from cattle, with raw milk or raw-milk cheeses as a typical vehicle for food-borne outbreaks [8,9].
A picture taken on November 18, 2011 shows a Morbier cheese from France during the European bi-annual Eurogusto slow food festival in Tours, central France. Slow Food, whose symbol is a red snail, promotes food that is “good at a sensory level,” but also aims to educate people about traditional and wholesome means of production and defend biodiversity in the food supply. AFP PHOTO/ALAIN JOCARD / AFP PHOTO / ALAIN JOCARD
In 2012, a major S. Dublin outbreak occurred in France, with 103 cases linked to Saint-Nectaire (bovine raw-milk cheese) consumption [10,11]. In 2015, 34 S. Dublin cases were reported linked to the consumption of Reblochon (bovine raw-milk cheese) (data not shown; Santé publique France).
In France, the National Reference Center for Salmonella (NRC) and the French Agency for Food, Environmental and Occupational Health and Safety (ANSES) routinely collect and serotype human and non-human Salmonella isolates, respectively [12–14], using the Kauffmann–White–Le Minor scheme . The S. Dublin isolates collected are frequently susceptible to all antibiotics and show an indistinguishable pulsed-field gel electrophoresis (PFGE) pattern. To better distinguish S. Dublin isolates, multilocus variable-number tandem repeat analysis (MLVA) has recently been used for surveillance and outbreak investigations [11,15]. Moreover, whole genome sequencing (WGS) of Salmonella has been shown to discriminate between closely related isolates of S. Dublin [16,17].
On 18 January 2016, the French NRC reported to Santé publique France (SpFrance, the French national public health agency) an excess of S. Dublin infections across the country, with 37 S. Dublin isolates identified between mid-November 2015 and mid-January 2016, compared with 10 S. Dublin isolates during the same period in the two previous years. An outbreak investigation team with experts from SpFrance, NRC, ANSES and the French Directorate General for Food (DGAL) launched extensive epidemiological, microbiological and food investigations to confirm the outbreak, identify the vehicle of transmission and propose appropriate control measures.
Disentangling a complex nationwide salmonella Dublin outbreak associated with raw-milk cheese consumption, France, 2015 to 2016,
Dr. Matt Willis, Marin County’s public health officer, said the closure was issued on Jan. 3. and on the following day the state health department issued a recall order on Tomales Bay oysters that had been sold to 34 restaurants by Hog Island Oyster Co., based in Marshall.
“There were 44 confirmed cases of norovirus between Dec. 29 and Jan. 5 across the Bay Area,” Willis said. “Only seven of those 44 cases were Marin cases.”
Willis said there is no concern in this case that the outbreak is related to food handling, cultivation or harvesting practices.
“It’s likely this represents contamination of the water itself,” he said. “The water testing showed high levels of bacterial and viral contamination, which is normal following high rainfall over a long interval.”
Willis said it is unusual for a norovirus outbreak to be linked to oysters. He said there are typically about 20 norovirus outbreaks every year in Marin County, and they usually occur in places where people congregate in close quarters such as schools or nursing homes.
There are plenty of Norovirus-related raw oyster outbreaks throughout the world weekly.
Maybe not in Marin County, Matt, but globally, yes.
My mother used to make and lot of cakes and brownies with her groovy 1960s hand mixer and I always got to lick the beaters.
And it’s not just the raw eggs, it’s the raw flour.
In June, 2009, an outbreak of shiga-toxin producing E. coli (STEC, primarily O157:H7) in Nestle Toll House cookie dough sickened at least 77 people in 30 American states. Thirty-five people were hospitalized – from cookie dough.
The researchers could not conclusively implicate flour as the E. coli source, but it remains the prime suspect. They pointed out that a single purchase of contaminated flour might have been used to manufacture multiple lots and varieties of dough over a period of time as suggested by the use-by dates on the contaminated product.
The study authors concluded that “foods containing raw flour should be considered as possible vehicles of infection of future outbreaks of STEC.”
So it wasn’t much of a surprise when 63 people fell sick from the outbreak strain of E. coli O121 from Dec. 2015 to Sept. 2016 linked to raw General Mills flour.
There have been about a dozen other flour-related outbreaks. STEC means people – and kids – get quite sick.
Flour is a raw commodity, crops the flour is derived from could be exposed to anything, and testing is so much better than it used to be.
There are some brands of pasteurized flour out there, but people seem to have gotten used to flour as a cheap source of play-dough-like stuff for kids and something to throw at people.
The U.S. Centres for Disease Control says, nope.
This is not a Christmas conspiracy (although I prefer Solstice Season): it’s CDC providing information, like they are supposed to.
People can, and will, do what they want.
As Maggie Fox of NBC reports, “Do not taste or eat any raw dough or batter, whether for cookies, tortillas, pizza, biscuits, pancakes, or crafts made with raw flour, such as homemade play dough or holiday ornaments,” the CDC advises.
“Do not let children play with or eat raw dough, including dough for crafts.”
Handling food, including flour, requires care and hygiene.
“Keep raw foods such as flour or eggs separate from ready-to eat-foods. Because flour is a powder, it can spread easily,” the CDC notes. “Follow label directions to refrigerate products containing raw dough or eggs until they are cooked. Clean up thoroughly after handling flour, eggs, or raw dough.”
Of the 83 people identified so far, 65 were able to be interviewed by the ARS Auvergne-Rhône-Alpes and Public Health France about their symptoms and their food consumption before the onset of symptoms. Symptoms range from 16/09 to 19/11, with a peak in week 40 (from 1st to 07/10/2018). Fifteen people were hospitalized for their salmonellosis: they are now out and are well; no deaths have been reported. Consumption of reblochon with raw milk before the onset of symptoms is reported by 80% of the cases confirmed by the CNR and interviewed.