The Public Health Agency of Canada is collaborating with provincial public health partners, the Canadian Food Inspection Agency, the Department of Fisheries and Oceans and Health Canada to investigate 67 Canadian cases of Vibrio parahaemolyticus infections in British Columbia and Alberta linked to raw shellfish. The majority of the illnesses have been linked to the eating of raw oysters.
The risk to Canadians is low, and illnesses can be avoided if shellfish are cooked before being eaten. People with weakened immune systems, young children, pregnant women and older adults are at increased risk for developing complications if they get sick.
Vibrio is a naturally-occurring bacterium that can be present at high levels in coastal waters during periods of increased water temperatures. Most people come in contact with Vibrio by eating raw or undercooked shellfish, especially oysters.
In Canada, a total of 67 cases have been reported in British Columbia (48) and Alberta (19). One case has been hospitalized. No deaths have been reported. Individuals became sick between June 1 and August 7, 2015 and all reported consumption of raw shellfish, primarily oysters. The investigation is ongoing to determine the source and distribution of these products.
People most at risk for complications are pregnant women, people with weakened immune systems, liver disease and low stomach acidity, young children and the elderly.
Most people recover fully within a week.
Foods contaminated with Vibrio may look, smell and taste normal.
The following safe food practices will reduce your risk of getting sick from Vibrio and other foodborne illnesses.
▪ Do not eat raw shellfish.
▪ Cook shellfish thoroughly before eating, especially oysters. Shellfish should be cooked to a safe internal temperature of 74°C (165°F).
▪ Discard any shellfish that do not open when cooked.
▪ Eat shellfish right away after cooking and refrigerate leftovers.
▪ Always keep raw and cooked shellfish separate.
▪ Avoid eating oysters, or other seafood, when taking antacids as reduced stomach acid may favour the survival and growth of Vibrio species.
▪ Always wash your hands for 20 seconds with soap after using the bathroom.
▪ Avoid exposing open wounds or broken skin to warm salt or brackish water, or to raw shellfish. Wear protective clothing (like gloves) when handling raw shellfish.
▪ Wash your hands well with soap before handling any food. Be sure to wash your hands, cutting boards, counters, knives and other utensils after preparing raw foods.
People infected with Vibrio can experience a wide range of symptoms. Some do not get sick at all, while others feel as though they have a bad case of stomach flu. Few people get seriously ill.
Most people develop one or more of the following symptoms 12 to 24 hours after being infected with the bacteria:
▪ watery or bloody diarrhea
▪ stomach cramps
▪ nausea
▪ vomiting
▪ fever
▪ headache
▪ chills
▪ abnormally low blood pressure
▪ bacteria present in the blood
The illness can last up to three days, and severe illness is rare. Patients should drink plenty of liquids to replace fluids lost through diarrhea.