Hundreds of people in the Pacific Northwest have become sickened by norovirus linked to the consumption of raw oysters harvested from coastal Washington and British Columbia.
Seattle-King County Public Health is investigating an apparent outbreak of norovirus from raw or undercooked oysters harvested in Washington between Jan. 10 and March 20. Officials report that as many as 39 people in the county were sickened after eating raw oysters in several different restaurants and at private events throughout the county.
In Canada, the Public Health Agency of Canada says consumption of raw and undercooked oysters has been blamed for the 321 cases of norovirus gastroenteritis in three Canadian provinces: British Columbia, Alberta, and Ontario.
British Columbia, where the contaminated oysters were harvested, has been the hardest-hit by the norovirus outbreak, with 223 cases of infection reported. There have been 56 cases in Ontario and 42 in Ontario.
People infected with norovirus experience nausea, vomiting, and diarrhea, all of which could be intense at times. Norovirus is notoriously contagious and can also be spread person-to-person by coming in direct contact with someone infected, or food, drink, or surfaces contaminated by an infected person.
Washington officials closed a small part of the Samish Bay growing area for all oyster species March 17. In Canada, the Department of Fisheries and Oceans had temporarily shut down seven shellfish aquaculture sites and has mandated additional control measures for shellfish processing until the outbreak is over.
Oysters and other bivalve mollusks feed on algae drawn from the water. Oysters take in about 50 gallons of water in a 24-hour period. As the water travels through the oyster, plankton, viruses, bacteria, and other pass over the gills and become concentrated within the shellfish.
Source: Food Safety News