As outdoor temperatures increase, so does the risk of illnesses associated with eating raw or undercooked bivalve shellfish (e.g. oysters, clams, mussels, scallops, cockles).
Vibrio parahaemolyticus is a naturally occurring bacterium found in shellfish that can cause illness in people. During the summer months, it is present in shellfish in higher concentrations. For that reason, the BC Centre for Disease Control (BCCDC) is reminding British Columbians to take necessary precautions before eating shellfish over the next few months.
"In order to eliminate risk completely, people should cook shellfish before eating it," advises Lynn Wilcott, acting program director of Food Protection Services with BCCDC, an agency of the Provincial Health Services Authority. "To ensure adequate cooking, test oysters with a meat thermometer and make sure the temperature reaches 90°C (195°F) for 90 seconds. This will kill the Vibrio bacteria and minimize the risk of infection."
To reduce the risk of illness, consumers are advised to keep shellfish cool by refrigerating immediately after purchase, carefully reading label instructions, using drinking-quality water to rinse ready-to-eat shellfish, and only purchasing live shellfish from approved sources. All bivalve shellfish sold to the public in B.C. must have a shellfish shipper's tag, which ensures federal inspection.
Illness caused by this bacteria can also be linked to raw oysters served in restaurants, bought at retail outlets, or self harvested raw shellfish, in communities throughout the province.
"People who eat raw oysters in restaurants, buy them from retail outlets or harvest oysters themselves need to be aware of the potential health risks," says Dr. Eleni Galanis, physician epidemiologist with BCCDC. "Consuming raw or undercooked shellfish can cause severe diarrhea and vomiting that can last up to a week."
In 2009, there were 34 cases of people in B.C. infected with Vibrio parahaemolyticus. There have not been any reported cases to date this year.
BCCDC, along with regional health authorities and partners within the federal and provincial governments, has been working with the shellfish industry to reduce the risk of contamination in commercially harvested shellfish.
For more information on food safety practices for consumers and individuals self-harvesting as well as licensing information for harvesting, please visit www.bccdc.ca
and to check for closures before self-harvesting visit www.pac.dfo-mpo.gc.ca
Anyone becoming ill with diarrhea and vomiting after eating shellfish should call HealthLink BC at 811. If symptoms are severe or persist, they should see their physician.