Oysters are filter feeders and can filter up and then hold the viruses.
There have been even more cases of oyster related Norovirus infections in Canada. In BC, hundreds have become infected with Norovirus after eating oysters.
Interesting, while there appears to be no link between outbreaks in the US and Canada because the cases in Washington are said to be linked to oyster from Washington, not Canada. But in the article, it states that the Canadians are said to export much of their product to the US,....so, could it be that these Canadian oysters really the oysters that caused illness in the US, but these oysters were labeled as such to make them appear local and these are linked to the cases further north? Or did someone eat the Canadian oysters neat the US waters, have a bout of illness, thus contaminating the US oysters? Or...it is just a weird occurrence that two oyster-related Norovirus outbreaks are happening at the same time?
In any event, eating raw oysters has a Norovirus risk, no matter how tasty they are.
Q13 Fox News
Raw oysters, norovirus warning issued after multiple people in area become ill
Posted 5:04 PM, March 28, 2017, by Q13 FOX News Staff, Updated at 11:12PM, March 28, 2017
SEATTLE — Public Health-Seattle & King County said Tuesday it has investigated “multiple reports” of persons ill with nausea, vomiting and diarrhea after eating raw oysters at some restaurants or private events in King County from Jan. 10 to March 20.
“We do not have laboratory confirmation for any of the cases, but symptoms are suggestive of norovirus. Often in norovirus outbreaks no laboratory testing is done.”
Public Health said as many as 39 people may have become ill.
The Washington State Department of Health said shellfish such as oysters, clams, and mussels are filter feeders and ingest norovirus if it is present in the water. Potential sources of contamination include faulty wastewater treatment plants, failing septic systems, stormwater runoff, dumping of boat sewage waste, and vomiting overboard near shellfish beds.
"Public Health has reported the illnesses to Washington State Department of Health (DOH) Shellfish Program which is responsible for tracking the reports and harvest locations of the oysters implicated in these illnesses. The oysters served at each of the meals in the table below were harvested from different growing areas/bays in Washington State with the exception of four meals, accounting for 22 of the reported illnesses, which included oysters harvested from a small area in the Samish Bay growing area; a section of that growing area was closed on 3/17/17 for all species," Public Health said in a news released.
Still no answers as B.C. oyster norovirus outbreak continues
Outbreak seems to be contained to B.C. despite widespread oyster exports
CBC News Posted: Mar 22, 2017 8:59 PM PT Last Updated: Mar 22, 2017 8:59 PM PT
There are still no answers as to what caused the B.C. oyster-related norovirus outbreak that has seen hundreds fall ill since December.
Federal agencies, including the Public Health Agency of Canada, the Department of Fisheries and Oceans (DFO) and the Canadian Food Inspection Agency (CFIA) have so far come up empty-handed since they started looking into the issue last month.
The Canadian Food Inspection Agency has tested many farms along the B.C. coast, but Pocock said that around 90 per cent have come back negative.
"This is a big puzzle," said Steven Pocock, who is the president of the Shellfish Growers Association and owner of the Sawmill Bay Shellfish Company. "Really and truly, nothing is different in this year as there has been in previous years."
The outbreak also seems to be entirely contained to British Columbia, even though some B.C. farms primarily export their oysters.
"This is another bizarre incidence," said Pocock. "We have farms which sell nearly 100 per cent of their production into the United States, for instance, and they have continued as per normal and are reporting no illnesses whatsoever."
The outbreak has not affected any other shellfish, Pocock said, because other varieties are generally cooked before being consumed.
Layoffs, reduced work at B.C. farms
Many B.C. shellfish farms have been temporarily closed by the DFO and CFIA.
Pocock's company, along with others, voluntarily stopped shipping in January. Since then, he's had to lay off many of his workers and reduce hours for the rest.
"As you can imagine, cash flow is pretty grim at the moment," he said.
Restaurants and grocery stores that rely on shellfish sales have also taken a hit, said Pocock.
The outbreak has lasted through Valentine's Day and the Lunar New Year, which he said are both traditionally high points for oyster sales.
"It's affected lots of businesses in quite a dramatic way," he said.
The worst is over
Though the outbreak continues, Pocock is confident that the worst of it is done.
"I think it's true to say that the peak is over," he said.
Pocock met with Minister of Agriculture Norm Letnick, who he said was "very receptive to our problems."
"We're hoping that the provincial government will step up to the plate and help us find the solution to this so that it doesn't happen again."
Pocock said growers need to find out the causes behind the outbreak, mitigate them and then go about winning back the public's trust.
"Going forward, we have to look at rebuilding our reputation, rebuilding our brand of B.C. oysters to give confidence back to the consumer," he said.
The B.C. Centre for Disease Control urges anyone who becomes ill with diarrhea and vomiting after eating shellfish to call B.C. HealthLink at 811.
With files from CBC Radio One's On the Coast