About Norovirus: Norovirus is a highly contagious virus and can be spread easily from person-to-person, through contaminated surfaces, and by eating contaminated food, including raw or undercooked oysters. Symptoms of norovirus usually begin 12 to 48 hours after a person has encounter the virus and can last for 1 to 3 days. Common symptoms include vomiting, diarrhea, nausea, and stomach cramps. People who develop symptoms of norovirus infection should consult their health care providers. Also, see: What do you need to know about Norovirus and Raw Oysters.
Norovirus makes its way into the marine environment through untreated human sewage (poop) and vomit. This may come from leaky septic systems, faulty wastewater treatment plants, boaters, or beachgoers. Shellfish are filter feeders, which means they filter seawater through their bodies to get food floating in the water. When norovirus particles are in the water, shellfish can accumulate the virus in their bodies. For a bit of history: A Baker’s Dozen of years of Oyster Norovirus Outbreaks.
Some oyster harvest areas in British Columbia that have been associated with illnesses in this outbreak have been closed as a part of the investigation. The CFIA has 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. Government of Canada Recalls and Safety Alerts:
Canada reports: As of April 8, 2022, there have been 328 cases of norovirus and gastrointestinal illness linked to consumption of British Columbia oysters reported in the following provinces: British Columbia (293), Alberta (3), Saskatchewan (1), Manitoba (15) and Ontario (16). Individuals became sick between mid-January and early April 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.
The CDC reports: As of April 6, 2022, at least 103 norovirus illnesses have been reported from 13 states: CDC is working with state and local partners to determine a more accurate number of illnesses in this outbreak and will update this number as more information is gathered. FDA Advises Restaurants and Retailers Not to Serve or Sell Potentially Contaminated Raw Oysters from Canada.
States impacted (thus far): California, Colorado, Florida, Hawaii, Illinois, Massachusetts, Minnesota, New Jersey, Nevada, New York, Oregon, Texas and Washington. Thus far California reports (34), Hawaii reports (4), Minnesota reports (29) and Washington reports (36).
Washington: (36) The Washington State Department of Health (DOH) has updated its advisory to Washington residents to not serve or eat certain oysters harvested from the south and central parts of Baynes Sound, British Columbia, Canada until further notice. The advisory is in alignment with the recent release from the U.S. Food and Drug Administration on a multi-state outbreak of norovirus illness linked to raw oysters. Twenty-six Washington residents have reported norovirus-like illness after eating oysters. Illnesses have been reported from residents of Clark, King, and Snohomish counties. Seattle King County Department of Health added 10 linked to oysters served at Il Terrazzo Carmine.
California: (34) The California Department of Public Health (CDPH) warned consumers April 2, 2022, not to eat raw oysters from British Columbia, Canada because they may be linked to an outbreak of norovirus illnesses in California. In California, at least 34 persons have become ill following the consumption of oysters at nine restaurants located throughout the state. Illness has been reported from March 11 through 19, 2022.
Minnesota: (29) On April 1, 2022, 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. 29 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.
Hawaii: (4) Hawaiian Health officials are warning the public of a norovirus outbreak linked to raw oysters from Canada that were distributed to restaurants and retailers in various U.S. states, including Hawaii, where several cases have been confirmed. The Hawaii Department of Health said as of late Tuesday, there have been four suspect cases of norovirus associated with raw oysters reported in the state. Three of the four suspect cases consumed raw oysters in Hawaii County, and one consumed raw oysters in Honolulu County, between March 8 and 22.