Canada Area Norovirus Outbreak: As of March 30, 2022, there have been 279 cases of norovirus and gastrointestinal illness linked to consumption of B.C. oysters reported in the following provinces: B.C. (262), Alberta (1), Saskatchewan (1), and Ontario (15). Individuals became sick between mid-January and late March 2022, and no deaths have been reported. Although not all cases of illness have been tested, testing of several cases has confirmed the presence of a norovirus infection.

Some oyster harvest areas in B.C. that have been associated with illnesses in this outbreak have been closed as a part of the investigation. Food recalls were conducted on February 18, March 20, March 23, and March 27, 2022 for oysters from B.C. For more information on the recalled products, please consult the Government of Canada’s Recalls and Safety Alerts website.

The CFIA is continuing its food safety investigation, which may lead to the recall of other products. If other products are recalled, the CFIA will notify the public through updated food recall warnings.

Acute gastrointestinal illnesses such as norovirus illness are common in North America and are very contagious, affecting all age groups. However, pregnant women, people with compromised immune systems, young children and the elderly are at risk for developing more serious complications, like dehydration.

People with norovirus illness usually develop symptoms of gastroenteritis within 24 to 48 hours, but symptoms can start as early as 12 hours after exposure. The illness often begins suddenly. Even after having the illness, you can still become re-infected by norovirus.

The main symptoms of norovirus illness are:

• diarrhea
• vomiting (children usually experience more vomiting than adults)
• nausea
• stomach cramps

Other symptoms may include:

• low-grade fever
• headache
• chills
• muscle aches
• fatigue (a general sense of tiredness)

Most people feel better within one or two days, with symptoms resolving on their own, and experience no long-term health effects. As with any illness causing diarrhea or vomiting, people who are ill should drink plenty of liquids to replace lost body fluids and prevent dehydration. In severe cases, patients may need to be hospitalized and given fluids intravenously. If you have severe symptoms of norovirus, consult your healthcare provider.

The Public Health Agency of Canada is collaborating with federal and provincial public health partners to investigate an outbreak of norovirus and gastrointestinal illnesses involving four provinces: British Columbia (B.C.), Alberta, Saskatchewan and Ontario.

Based on the investigation findings to date, the outbreak is linked to consumption of raw oysters from B.C. Some oyster harvesting areas in B.C. that have been associated with illnesses in this outbreak have been closed as a part of the investigation. These closures aim to prevent further illness.

Food recalls were conducted on February 18, March 20, March 23, and March 27, 2022 for oysters from B.C. Links to each food recallassociated with this investigation can be found at the end of this public health notice. The Canadian Food Inspection Agency (CFIA) is continuing its food safety investigation, which may lead to the recall of other products. If other products are recalled, the CFIA will notify the public through updated food recall warnings.

Do not eat, use, sell, or serve the recalled oysters.

Also, avoid eating raw or undercooked oysters to reduce your risk of foodborne illness and follow proper food handling practices. Cook oysters to an internal temperature of 90° Celsius (194° Fahrenheit) for a minimum of 90 seconds.

The outbreak investigation is ongoing and additional actions to protect public health will be taken as needed. This public health notice will be updated as the investigation evolves.

Minnesota Area Norovirus Outbreak: The Minnesota Department of Health, Hennepin County Public Health, and the Minnesota Department of Agriculture are working with federal officials and public health agencies in other states and Canada to investigate norovirus illnesses associated with oysters harvested from Bay 14-8 in British Columbia.

Twenty-nine Minnesotans have been sickened in this outbreak. They became ill with confirmed or suspected norovirus gastroenteritis after eating raw oysters at Travail Kitchen in Robbinsdale on March 20. The oysters served were Stellar Bay Gold oysters harvested on March 10 from Deep Bay 14-8 CLF #140706 in British Columbia, Canada.

“Travail Kitchen quickly brought the cases to our attention, and immediately stopped serving oysters,” said Duane Hudson, Hennepin County Public Health, Environmental Health manager. “We are grateful to Travail for their help in protecting the public from foodborne illnesses.”

While some parts of the harvest area have been closed, it is likely that oysters from this area are still in the marketplace. With that in mind, officials are urging restaurants and distributors to check shellstock tags and discard oysters from this harvest area. Consumers can ask oyster suppliers or restaurants to check the shellstock tag for the harvest location. Norovirus and other pathogens found in raw oysters can be destroyed by cooking to 145 degrees Fahrenheit before eating.

Symptoms of norovirus typically include nausea, vomiting, diarrhea, or stomach cramps that begin 12 to 48 hours after ingestion of the virus. There is currently a high level of norovirus illness activity in Minnesota, and most is not associated with eating oysters.

“People with norovirus can spread it to others even after symptoms stop,” MDH Epidemiologist Supervisor Senior Carlota Medus said. “The best way to limit spread is to wash your hands well with soap and water after using the bathroom and before preparing food for others.”

Seattle Area Norovirus Outbreak: Public Health routinely reports the illnesses to Washington State Department of Health (DOH) Shellfish Program, which is responsible for tracking the harvest locations of the oysters implicated in these illnesses. Multiple illnesses tracked to a common growing area may result in the closure of implicated harvest locations or other enforcement actions.