The closing of the shellfish beds in Wellfleet was prompted after 75 people became ill with norovirus over a period of two days, the result of eating raw, contaminated oysters at weddings and restaurants in the Outer Cape Cod area, according to the Massachusetts Public Health Advisory.
The DPH Food Protection Program has also notified local businesses, having them recall any shellfish harvested on or after September 26, 2016.
Although other Cape Cod shellfish harvesting areas are not affected, the harvesting of oysters and other shellfish in Wellfleet will be closed for at least three weeks. The current closed areas include Wellfleet Harbor, Wellfleet Inner Harbor, Herring River and Loagy Bay.
According to Food Safety News, Katie Gronendyke, a spokeswoman for the Massachusetts Division of Marine Fisheries in Boston says, “The National Shellfish Sanitation Program requires a minimum closure of 21 days. The state has to demonstrate that there are no ongoing pollution problems by conducting a resurvey of the area and an evaluation of all real and potential pollution sources.”
Hillary Greenberg-Lemos, the town of WellFleet’s health and conservation agent says it’s not clear how many businesses will be affected by the closing of the shellfish beds. Local harvests of oysters, mussels and clams are shipped all over the world.
The lack of raw oysters could have put a huge dent in the 16th annual Wellfleet OysterFest that took place over the past weekend, but while no raw oysters were to be found, all the oysters served cooked were sourced from outside the area.
Wellfleet SPAT board member Alex Hay said on their web page that the festival would go on, adding “Not only is public safety our main concern, it is also in the seafood industry’s best interest, the town’s best interest, and the Wellfleet brand’s best interest.”
Oysters not only transmit human norovirus, but they are a major reservoir for this pathogen. Oysters are the perfect vectors for the bug because shellfish beds are located in coastal waters that are frequently contaminated by human waste.
Research has shown that with oysters being filter-feeders, the norovirus can persist in the oyster’s tissues for weeks, even after measures have been taken to clean up the pollution.
According to the Centers for Disease Control and Prevention (CDC), norovirus is extremely contagious, and around 20 million cases, including 56,000-71,000 hospitalizations and 570-800 deaths are recorded in the U.S. every year.