The quasi-daily probe E1: The okra of the sea

My friend Mike Batz of University of Florida’s Emerging Pathogen Institute and I were chatting a while back and thought it would be cool to connect for short podcasts when there was something fun going on. Here’s the first episode (and maybe the last) in it’s raw, unedited, short format.Daily-probe

Today we talked about oysters, raw and steamed, Vibrio, norovirus, burden and risk-based messaging.

The article that prompted the probe was from Lifezette where oysters are referred to as those scary shellfish.

Heads up, raw oyster lovers. New research from China shows the bivalves not only transmit human norovirus, they also serve as a reservoir for the harmful and highly contagious virus.

In an expansive study published recently in Applied and Environmental Microbiology, a journal of the American Society for Microbiology, scientists discovered that more than 80 percent of the known noroviruses matched those found in oysters.

Even common recommendations for reducing the risks of illness, such as avoiding them from warm-water sources, aren’t a guarantee you won’t get sick, food safety expert Ben Chapman told LifeZette.

“Considering where they’re from, and not eating them at a certain time of year, may reduce the risk, though risk is always there,” said Chapman, a researcher at North Carolina State University. Chapman also notes that cooking oysters may lower risk, but that steaming — a popular way to prepare them — isn’t likely to get them above 140 degrees.

Listen to the episode here.

35 sick: raw is risky in rising temperatures in BC

A warning from the BC Centre for Disease Control about eating raw shellfish:

So far this summer, there have been an unprecedented number of shellfish-related illnesses thanks to the warm weather.

SUN0705N-Oyster7The majority of illnesses have been linked to eating raw oysters sourced in BC and served in restaurants.

Spokesperson Marsha Taylor says 35 people have become ill from eating the uncooked shellfish…

“We’re putting this message out both to the public that will also hit the restaurants and we’re also doing follow up with every restaurant to make sure they are aware of the issue and we’re inspecting the premises.”

Some illnesses have also been linked with raw oysters purchased or self-harvested.

Taylor says if you happen to get sick…

“People who are experiencing symptoms of the Vibrio Parahaemolyticus most often experience typical food-borne illness like nausea and vomiting, headaches, and feel pretty badly for a couple of days…but most people will recover on their own.”

To reduce risk of illness consumers are being told to eat only cooked shellfish.

Proposal to close Washington oyster beds when temperatures rise

Vibrio is one of the nastier foodborne pathogens, one of the reasons why I don’t go near raw oysters (the other being that I just don’t like them). In 2014, Washington oyster producers dealt with the fallout from over 70 Vibrio cases linked to their products. The illnesses caused beds to be closed for two months and now, according to AP, the WA State Department of Health is proposing rules that would close the harvest areas proactively.

Local shellfish growers support the recommendations, saying the changes would better protect public health without creating hardships for the local industry.oyster-hi-res__72926.1405431595.1280.1280

“I think that’s a more reasonable way of approaching the problem,” Blau Oyster Co. owner Paul Blau said.

Following the seasonlong closure last year, Blau received a state exemption that allowed his company to sell shucked oysters with warning labels. It helped, but the small business still felt an impact.

“Not being able to sell live oysters in the shells . that’s kind of our high-priced product that we sell that time of year,” Blau said.

Under current regulation, inland areas like Samish Bay are subject to summerlong closures if four illnesses are traced back.

“That means a lot of closures are taking place in August and September, when we know most illness occurs in July and August,” state Office of Shellfish and Water Protection spokeswoman Laura Johnson said.

The revision would set water temperature thresholds that would result in shorter harvest times or full closures when exceeded.

“We’re excited about the change. It will be a positive one for public health . and we don’t think we’ll be closed any more than we have historically. We will just be closed proactively,” Taylor Shellfish Farms spokesman Bill Dewey said.

For inland areas, harvest closures would occur at 66 degrees and last until 24 hours after the temperature drops.

Oyster harvesters would also be required to cool shellfish to 50 degrees or less within five hours, as well as report harvest quantity and water temperature to the state agency.

“We know the growth of vibrio is so tied to temperature, it only makes sense that you’re going to be required to record temperatures when you harvest,” Dewey said.

To date, the Department of Health has tracked reports of vibrio-related illness, but not the quantity of oysters sold. The new data-filing requirement will enable the agency to look at the ratio of sickness to the number of oysters consumed.

“Everybody has been frustrated by our historic way of managing vibrio in the state . What we’ve done historically is monitor for illnesses, and then when we get those illnesses we shut it down,” Dewey said. “That’s a really bad way to manage public health, but we didn’t have another tool to do it. I think we’ve come up with a solution in this new rule.”



Polio virus released into Belgian waters; The Netherlands issue shellfish warning

The Dutch Food Safety and Health Authorities issued a warning (computer translated) against the consumption of raw, improperly cooked shellfish (mainly oysters) harvested by individuals in the eastern part of the Westerschelde river in response to the 45 litres of concentrated live polio virus solution accidentally released into Belgium water sources by Glaxo SmithKline earlier this month.

Raw oystersThe Netherlands National Institute for Public Health and the Environment (RIVM) said in a release Monday (computer translated), The risk of infection with the poliovirus is very small. Since its release to the River Avenue, the concentration is diluted so much that the water itself is not a threat. However, shellfish filter water and the amount of virus can be higher than in the shell than in the water. Even then the chance to get infected even very small. But in the Netherlands, we are very cautious when it comes to polio. Along the Westerschelde are a number of municipalities with low vaccine coverage where many children are not protected against diseases like polio . When it comes poliovirus in such a community, there is great likelihood that many people get sick.

Belgium gave no such recommendations as the country’s polio vaccination rates are better than the Netherlands, according to the RIVM.

Martha’s Vineyard oysters could cause foodborne illness

Now that it’s September, it’s unofficially oyster season in New England. Having grown up amongst Greater Boston’s idyllic fishing communities, I’ve abided by the old adage only eat oysters during months that end in ‘ber.’ September is no exception; except for the fact that oyster beds off the coast of Edgartown on Martha’s Vineyard have been closed.

Coos Bay Oyster Co.On Wednesday afternoon, the Massachusetts Department of Public Health and the Massachusetts Department of Fish and Game, Division of Marine Fisheries announced the precautionary closure of the oyster beds in Katama Bay. The two departments determined that a certain environmental condition has become present which can often lead to an infestation of Vibrio parahaemolyticus – a bacteria that can cause gastrointestinal illness when ingested.

Vibrio outbreak prompts changes in oyster handling

I’ve only once had raw oysters, on a trip to New Zealand while in graduate school where some Kiwi food safety folks urged me to try the delicacy.

They were slimy.

I determined that the taste benefit wasn’t worth the risks for me.

According to the Vineland Gazette, a 2013 outbreak of Vibrio parahaemolyticus, linked to Katama Bay (MA) oysters prompted the Massachusetts Massachusetts Department of Fish and Game, Division of Marine Fisheries and the Department of Public Health, Bureau of Environmental Health, Food Protection Program to develop a plan to limit Vibrio risks.SUN0705N-Oyster7

A Vp control plan takes effect next month that will require faster cooling and delivery of oysters, changes in handling methods for harvesters, specific requirements for icing and new rules for record keeping among commercial oyster growers.

Backed by the state Division of Marine Fisheries, the rules will be in effect from May 19 through Oct. 19. The U.S. Food and Drug Administration recommended last year that Massachusetts develop a plan to control Vp during the warm weather months to prevent illness. 

FSA seeking for research on norovirus removal from oysters

Norovirus in oysters is a global issue and the UK Food Standards Agency, home of piping hot, is looking for some research help. As the virus bioaccumulates and is tough to cook out of shellfish, lots of folks are looking for virus removal strategies.Beautiful-Opened-Oyster

According to Fish Farmer, the Food Standards Agency (FSA) is inviting tenders to design and execute a research study to identify and evaluate possible enhancements to improve norovirus removal from live oysters during shellfish depuration processes.

The FSA wants to commission work to quantify and optimise the effectiveness of standard UK depuration practices in reducing norovirus in oysters and to explore the potential for novel approaches to significantly improve the effectiveness of this process.

The study should include reviews of relevant available evidence (published and unpublished) as the starting point for a fully justified laboratory-based project which will improve the controls that can be applied to current UK depuration practices, to reduce the levels of norovirus in oysters sold for public consumption.

Maybe Heston Blumenthal is on the review panel.  If so, research into food handlers working while ill might predictably be next on the docket.

2013 Colchester Oyster Feast source of outbreak

The Colchester Oyster Feast is kind of a big deal. Dating back to the 14th century and boasting a couple of to-be-kings as former guests (King Edward VIII and King George VI) it is the place to be in October. The event even has its own Wikipedia page.

And in 2013, it also was the source of an outbreak.1891cs

According to the Essex County Standard, 54 attendees became ill after eating Irish oysters at the annual festival.

A total of 200 guests attended the civic event at Colchester’s Moot Hall last October.
Within days, 13 guests reported they were unwell and an investigation was launched by Public Health England.

Questionnaires were sent out and 54 people reported they had been sick, including Colchester Council chief executive Adrian Pritchard.

3 sick with Campylobacter in Oregon, Coos Bay Oyster recalls shucked and in-shell oysters

Lynne Terry writes that Coos Bay Oyster Co. is recalling oysters over a food poisoning outbreak that has sickened at least three people in Oregon.

The company, based in Charleston, said it is pulling all of its shucked oysters and in-shell oysters sold to retail stores and wholesalers in Oregon and California.

The shucked oysters were sold in 1/2 gallon, quart, pint and half-pint containers with sell-by dates from Jan. 15 to Feb. 17. The containers carry the Coos Bay Oyster Co. label and Coos Bay Oyster Co.are marked raw/ready-to-eat shucked oysters.

The oysters in-shell were distributed in red onion sacks, each containing five dozen oysters of various sizes. They, too, have the company’s label, with harvest dates from December 2013 to January 2014.

59 sick; summer of shellfish outbreaks

In Seattle, King County health officials report there were 13 suspected cases of the saltwater bacteria Vibrio parahaemolyticus in the county during July, compared to an average of four reported in that month in recent years. Since the beginning of, an additional eight cases have been confirmed, while King County would typically only see six for the entire month.

Across Washington state, more than 40 residents have gotten sick with vibriosis.

“This is probably the tip of the iceberg,” said Dr. Jeff Duchin, chief of communicable disease for Seattle & King County Public Health. “For every case that is reported, an estimated 142 additional cases go unreported.”

People typically get vibriosis from eating raw or undercooked shellfish, particularly oysters. Residents who have pre-existing medical conditions or who take antacids regularly are at higher risk for illness from the vibrio infection.

Since June 2013, Connecticut has reported 19 confirmed cases of Vibrio parahaemolyticus infection, compared to an average of seven cases reported during the same time period in the past two years.

Shellfish should be cooked to an internal temperature of 145 degrees for at least 15 seconds, according to the U.S. Centers for Disease Control.

Not sure where that number came from, but I grill mine.

The Canadian Food Inspection Agency (CFIA) is warning the public not to serve or consume the raw shellfish products below because they may contain paralytic shellfish toxins that can cause illness if consumed.

These shellfish products were primarily distributed to wholesalers and institutional clients such as restaurants. However, the affected shellfish products may also have been sold in smaller quantities at some retail seafood counters. Consumers who are unsure whether they have the affected products are advised to check with their retailer or supplier.

These products have been distributed in Alberta and British Columbia. However, they may have been distributed in other provinces and territories.