Vibrio parahaemolyticus is a leading cause of seafood-borne gastroenteritis. Given its natural presence in brackish waters, there is a need to develop operational forecast models that can sufficiently predict the bacterium’s spatial and temporal variation.
This work attempted to develop V. parahaemolyticus prediction models using frequently measured time-indexed and -lagged water quality measures. Models were built using a large data set (n = 1,043) of surface water samples from 2007 to 2010 previously analyzed for V. parahaemolyticus in the Chesapeake Bay. Water quality variables were classified as time indexed, 1-month lag, and 2-month lag. Tobit regression models were used to account for V. parahaemolyticus measures below the limit of quantification and to simultaneously estimate the presence and abundance of the bacterium. Models were evaluated using cross-validation and metrics that quantify prediction bias and uncertainty.
Presence classification models containing only one type of water quality parameter (e.g., temperature) performed poorly, while models with additional water quality parameters (i.e., salinity, clarity, and dissolved oxygen) performed well. Lagged variable models performed similarly to time-indexed models, and lagged variables occasionally contained a predictive power that was independent of or superior to that of time-indexed variables. Abundance estimation models were less effective, primarily due to a restricted number of samples with abundances above the limit of quantification. These findings indicate that an operational in situ prediction model is attainable but will require a variety of water quality measurements and that lagged measurements will be particularly useful for forecasting.
Future work will expand variable selection for prediction models and extend the spatial-temporal extent of predictions by using geostatistical interpolation techniques.
IMPORTANCE Vibrio parahaemolyticus is one of the leading causes of seafood-borne illness in the United States and across the globe. Exposure often occurs from the consumption of raw shellfish. Despite public health concerns, there have been only sporadic efforts to develop environmental prediction and forecast models for the bacterium preharvest.
This analysis used commonly sampled water quality measurements of temperature, salinity, dissolved oxygen, and clarity to develop models for V. parahaemolyticus in surface water. Predictors also included measurements taken months before water was tested for the bacterium. Results revealed that the use of multiple water quality measurements is necessary for satisfactory prediction performance, challenging current efforts to manage the risk of infection based upon water temperature alone.
The results also highlight the potential advantage of including historical water quality measurements. This analysis shows promise and lays the groundwork for future operational prediction and forecast models.
Vibrio parahaemolyticus in the Chesapeake Bay: Operational in situ predition and forecast models can benefit from inclusion of lagged water quality measurements
Public and Environmental Health Microbiology
Benjamin J. K. Davis, John M. Jacobs, Benjamin Zaitchik, Angelo DePaola, Frank C. Curriero
We’ve done extensive work on this topic dating back to 2006 (search barfblog.com), but new tools, like whole genome sequencing, mean additional outbreaks have been identified. A summary paper of recent outbreaks has just been published. Abstract below:
Frozen raw breaded chicken products (FRBCP) have been identified as a risk factor for Salmonella infection in Canada. In 2017, Canada implemented whole genome sequencing (WGS) for clinical and non-clinical Salmonella isolates, which increased understanding of the relatedness of Salmonella isolates, resulting in an increased number of Salmonella outbreak investigations. A total of 18 outbreaks and 584 laboratory-confirmed cases have been associated with FRBCP or chicken since 2017. The introduction of WGS provided the evidence needed to support a new requirement to control the risk of Salmonella in FRBCP produced for retail sale.
Outbreak of salmonella illness associated with frozen raw breaded chicken products in Canada 2015-2019
Frank didn’t waste any time after leaving Wal-Mart for government.
Good on ya.
But guidance is not enforcement.
My group learned that the hard way 20 years ago.
And they still serve sprouts to immunocompromised people in Australian hospitals despite a ridiculous number of outbreaks.
“Over the past 22 years, the U.S. Food and Drug Administration (FDA) has investigated 50 reported outbreaks of foodborne illness associated with contaminated sprouts. Together, these outbreaks resulted in more than an estimated 2,600 cases of illness. Last year, there were two reported outbreaks associated with sprouts, resulting in more than an estimated 100 illnesses. Studies indicate that contaminated seed is the likely source of most sprout-related outbreaks, as this commodity is inherently more susceptible to these issues because they are grown in warm and humid conditions that are favorable for bacteria like Salmonella, Listeria and E. coli,” said FDA Deputy Commissioner for Food Policy and Response Frank Yiannas.
“The FDA is committed to taking swift action to respond to outbreaks related to sprouts and keep our food supply safe, but we also know that measures to prevent issues from happening in the first place are an important element of protecting consumers. By studying outbreaks related to sprouts over the years, we have been able to recommend changes in the industry to help lower the incidence of sprout-related outbreaks. Today’s new draft guidance is another critical step, like the Sprout Safety Alliance or sprout-specific requirements of the Produce Safety Rule, the agency is taking to prevent illnesses related to sprouts.”
FDA today released a proposed draft guidance, “Reducing Microbial Food Safety Hazards in the Production of Seed for Sprouting,” intended to make the sprout seed industry (seed growers, conditioners, packers, holders, suppliers, and distributors) aware of the agency’s serious concerns with the continuing outbreaks of foodborne illness associated with the consumption of raw and lightly-cooked sprouts.
Incorporating aspects of the Codex Code of Hygienic Practice for Fresh Fruits and Vegetables Annex II, Annex for Sprout Production; the International Sprout Growers Association-Institute for Food Safety and Health’s “U.S. Sprout Production Best Practices”; and Good Agricultural Practices, the FDA’s draft guidance issued today provides the agency’s recommendations to firms throughout the production chain of seed for sprouting. It states that if a grower, holder, conditioner, or distributor reasonably believes that its seeds are expected to be used for sprouting, we recommend that the grower, holder, conditioner, or distributor take steps that are reasonably necessary to prevent those seeds from becoming contaminated. We also recommend that firms throughout the supply chain – from seed production and distribution through sprouting – review their current operations related to seeds for sprouting.
SA Health has confirmed 11 cases of salmonella have been reported after people ate Vietnamese rolls from three Angkor Bakery stores.
Deputy chief medical officer Dr Nicola Spurrier said that of those eleven people, nine were hospitalised due to the severity of the poisoning.
“Early investigations indicate the cases could be linked to raw egg butter, pate or BBQ pork ingredients.
“The businesses complied with a council request on Tuesday to cease using these ingredients and, from today, the businesses have agreed to cease selling all Vietnamese rolls until the source has been identified.
“Cleaning and sanitising procedures have also been assessed and improved,and will continue to be monitored.”
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.
Jason Steen of Scoop Nashville reports that newly filed court documents reveal Milk & Honey served salmonella-tainted ‘short rib gnocchi’ to patrons during August of 2018, causing over 20 patrons to fall ill with salmonella poisoning, and the Metro Health Department to deem it an outbreak.
Between August 3rd and August 15th of 2018, more than 20 patrons of Milk & Honey, a restaurant on 11th Ave S in the Gulch, were diagnosed with salmonella poisoning, according to the Metro Health Department, who formally deemed the incident an ‘outbreak’. Environmental, epidemiological, and lab testing linked the outbreak to the raw egg product furnished to Milk & Honey by a vendor, Gravel Ridge Farms. Specifically, they found the gnocchi was were only being cooked to 130 degrees, well below the required 145 degree required cook-kill temperature.
Documents from the lawsuit and Metro Health reveal:
Milk & Honey purchased unpasteurized raw eggs and/or raw egg product from Gravel Ridge Farms to be used in food prep, as part of their desire to source “local foods”
Milk & Honey used the unpasteurized eggs in a featured menu item: ‘Short Rib Gnocchi’. The gnocchi portion of this dish involves fashioning flour and raw egg yolk into dough, cutting it into pieces, and placed on a pan for freezing.
A plaintiff in the lawsuit dined at Milk & Honey in August of 2018, after which he fell sick with symptoms that found him hospitalized at Centennial Medial Center, which was diagnosed as salmonella poisoning.
At least 20 additional patrons were diagnosed with salmonella poisoning after eating the same dish.
An investigation by the Metro Health Department found a ‘lack of management oversight’ into the preparation of the short rib gnocchi. During their initial interview with the restaurant management, boiling of the raw gnocchi was indicated, however, in a reconstruction of events, it was learned that boiling did not take place in the actual kitchen production of the dish. It was being pan-seared upon each order, instead of boiled.
The Metro Health Department also found a lack of training to be a factor. The employee responsible for the final cooking and preparation of the dish was not unfamiliar with Gnocchi and was not trained on measuring or verifying final cooking temperatures of the raw gnocchi.
Taylor Monen, who is the owner of Milk & Honey, wrote a follow-up letter to Metro Health, which reads, in part:
After your visit on Friday, we felt that our past cook that evening probably did not cook the gnocchi long enough to reach a temperature that would have completely killed this bacteria present in the gnocchi…
I am not certain that I will be keeping it on the menu unless I am able to acquire pasteurized egg product that we can use to make these gnocchi noodles.
During the same email, Monen acknowledges the dangers of using small farms for egg sourcing, and acknowledged safer alternatives were readily available from food suppliers.
The newly filed lawsuit claims seeks claims of negligence in the amount of $575,000.00 & punitive damages up to $1,000,000.00.
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.”
There’s nothing like people forking over huge coin only to end up barfing.
Irony is sometimes ironic.
The Iceland Monitor reports infected Icelandic oysters caused food poisoning for 48 individuals at Skelfisksmarkaðurinn, a relatively new restaurant owned by succcessful tv chef and restaurant owner Hrefna Sætran. Icelandic oysters are a novelty in Iceland as all oysters on menus until now have been imported from Ireland or other countries.
The oysters were imported as youngsters and raised in Skjálfandaflói bay by company Víkurskel. This is the first time that the noro virus is confirmed in oysters in Iceland.
Forty-four individuals ate oysters at the restaurant from November 8th to November 13th and four further individuals ate oysters between October 29th and November 4th. Oysters infected by the noro virus were on the menu during this period of time, confirms the Icelandid food and veterinary authority. According to the health authorities they found that the restaurant complied to all regulations and standards with regards to food safety and hygiene.