U.S. CDC has yet to weigh in.
The Public Health Agency of Canada collaborated with federal and provincial public health partners, the United States Centers for Disease Control and Prevention (U.S. CDC), and the U.S. Food and Drug Administration to investigate an outbreak of norovirus and gastrointestinal illnesses involving five provinces: British Columbia, Alberta, Saskatchewan, Manitoba and Ontario. The outbreak appears to be over, and the outbreak investigation has been closed.
Investigation findings identified consumption of raw oysters from British Columbia as the source of the outbreak. As a result, some oyster harvesting areas in British Columbia that were associated with the outbreak were closed as a part of the investigation.
The Canadian Food Inspection Agency (CFIA) issued several food recalls throughout February, March, and April. Links to each food recall associated with this investigation can be found at the end of this public health notice.
The outbreak investigation is an important reminder to Canadians and businesses that raw oysters can carry harmful germs that can lead to foodborne illness if not properly handled and cooked prior to consuming.
In total, 339 confirmed cases of norovirus and gastrointestinal illness were reported in the following provinces: British Columbia (301), Alberta (3), Saskatchewan (1), Manitoba (15) and Ontario (19). Individuals became sick between mid-January and early April 2022, and no deaths were reported.
Some oyster harvest areas in British Columbia that were associated with illnesses in the outbreak were closed as a part of the investigation. The CFIA issued several food recalls throughout February, March, and April. For more information on the recalled products, please consult the Government of Canada’s Recalls and Safety Alerts website.
The U.S. CDC also investigated a multistate norovirus outbreak linked to raw oysters from British Columbia. To date the CDC has reported the following illnesses: 103 illnesses have been reported as of April 6, 2022. States affected: California, Colorado, Florida, Hawaii, Illinois, Massachusetts, Minnesota, New Jersey, Nevada, New York, Oregon, Texas, and Washington.
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:
- vomiting (children usually experience more vomiting than adults)
- stomach cramps
Other symptoms may include:
- low-grade fever
- 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.
Raw oysters contaminated with noroviruses may look, smell and taste normal. The following safe food-handling practices will reduce your risk of getting sick:
- Do not eat, use, sell, or serve any recalled oysters.
- Avoid eating raw or undercooked oysters. Cook oysters to an internal temperature of 90° Celsius (194° Fahrenheit) for a minimum of 90 seconds before eating.
- Discard any oysters that did not open while cooking.
- Eat oysters right away after cooking and refrigerate leftovers.
- Always keep raw and cooked oysters separate to avoid cross-contamination.
- Do not use the same plate or utensils for raw and cooked shellfish, and wash counters and utensils with soap and warm water after preparation.
- Wash your hands well with soap before and after handling any food. Be sure to clean and sanitize cutting boards, counters, knives, and other utensils after preparing raw foods.
Noroviruses can be transmitted by ill individuals and are able to survive relatively high levels of chlorine and varying temperatures. Cleaning and disinfecting practices are the key to preventing further illnesses in your home.
- Thoroughly clean contaminated surfaces, and disinfect using chlorine bleach, especially after an episode of illness.
- After vomiting or diarrhea, immediately remove and wash clothing or linens that may be contaminated with the virus (use hot water and soap).
- If you have been diagnosed with norovirus illness or any other gastrointestinal illness, do not prepare food or pour drinks for other people while you have symptoms, and for the first 48 hours after you recover.
Norovirus: Marler Clark, The Food Safety Law Firm, is the nation’s leading law firm representing victims of Norovirusoutbreaks. The Norovirus lawyers of Marler Clark have represented thousands of victims of Norovirus and other foodborne illness outbreaks and have recovered over $800 million for clients. Marler Clark is the only law firm in the nation with a practice focused exclusively on foodborne illness litigation. Our Norovirus lawyers have litigated Norovirus cases stemming from outbreaks traced to a number of food products and restaurants.