Vancouver – The BC Centre for Disease Control has confirmed the first case of illness this summer linked to the bacterium known as “Vibrio” (Vibrio parahaemolyticus) and the consumption of raw oysters.
Vibrio grows in seawater and accumulates in shellfish like oysters and clams. It is especially prevalent during the summer when seawater temperatures rise. When consumed in raw or undercooked shellfish, it can cause illness including fever, vomiting and diarrhea.
The largest outbreak in BC history occurred last year when 60 people became ill from eating raw or undercooked BC oysters, and another 13 from exposure to seawater with elevated bacteria levels. The majority of people who became ill from oysters consumed them in restaurants, although several cases were associated with raw oysters bought at retail outlets or self-harvested.
This year’s illness was reported June 30, a full two weeks later than last year’s cases began to emerge. And although the person consumed the raw oysters in the Vancouver area, experts from BCCDC warn eating raw shellfish from any source can pose a risk of making you ill.
“Eating raw shellfish increases your risk of Vibrio and other infections,” said Dr. Eleni Galanis, epidemiologist at the BCCDC. “It’s best to eat them cooked, but if you choose to eat raw shellfish like oysters, then understand the risks and take steps to reduce your likelihood of illness.”
Oysters packaged without a shell are intended to be cooked; do not eat them raw. If you are planning to harvest shellfish, ensure the area is open for harvesting, always keep shellfish cold and only harvest on receding tides.
The BCCDC has launched new tools for Vibrio control
on its website. These include a Vibrio
growth calculator, a temperature mapping tool and a shellfish openings and closures map.
BCCDC and its partners including industry, public health officials and regulators are also working on a number of other initiatives to improve control, education, communication and surveillance:
- Restaurants throughout BC now include menu warnings;
- Developing an improved model to predict Vibrio parahaemolyticus growth with environmental conditions;
- Improved information collection during investigations of illness.
Anyone becoming ill with diarrhea and vomiting after eating shellfish should call BC HealthLink at 811. If symptoms are severe or persist, they should see their physician.
The BC Centre for Disease Control, an agency of the Provincial Health Services Authority, provides provincial and national leadership in public health through surveillance, detection, treatment, prevention and consultation services. The Centre provides both direct diagnostic and treatment services for people with diseases of public health importance and analytical and policy support to all levels of government and health authorities.
Provincial Health Services Authority
604-675-7481 or pager: 604-871-5699