Canada's food supply is among the safest in the world, but sometimes the food we eat could contain bacteria, like Vibrio. that could make us sick.

What are vibrios?

Vibrios are toxin-producing bacteria that are found naturally in water, fish and shellfish. Vibrios are usually transferred to people when they eat food or drink beverages that are contaminated. There are several types of vibrios that can cause illness, including the salt-loving vibrios which mainly live in marine environments, such as V. parahaemolyticus, V. vulnificus and V. alginolyticus, and the freshwater vibrios, such as V. cholerae.

People who are infected with disease-causing vibrios may develop foodborne illness. Foodborne illness symptoms can vary from a mild to serious illness, depending on a variety of factors.

How do people get sick?

V. parahaemolyticus live in brackish (mixed fresh and salt) water and causes a gastrointestinal illness, ususally mild in healthy humans. It is found naturally in coastal waters in Canada and the United States, with higher concentrations in the summer. Most people come in contact with V. parahaemolyticus by eating raw or undercooked shellfish, especially oysters. People can also pass on the bacteria to others through infected stool.

Did you know?

Foodborne illness can be caused by viruses, bacteria or parasites, and usually involves diarrhea and occasional vomiting. It is often misdiagnosed with other illnesses.

Vibrio alginolyticus, V. fluvialis and V. vulnificus are also found in the Canadian coastal waters and may be acquired through the consumption of seafood which may also cause illness.

People usually become infected with V. cholerae when travelling to countries in the tropical region, by eating or drinking contaminated food or drinks. V. cholerae causes cholera, an often severe gastrointestinal illness. Cholera is a disease of global concern and some strains are still spreading in various countries. Food and water can become contaminated through contact with any of the following: infected vomit, contaminated stool, unclean hands, or flies.

What are the symptoms and treatment?

People with V. parahaemolyticus usually get a mild intestinal illness. Most people develop one or more of the following symptoms 12 to 24 hours after being infected with the bacteria:

  • diarrhea (watery)
  • stomach cramps
  • nausea
  • vomiting
  • fever
  • headache

Did you know?

In addition to the usual symptoms for V. parahaemolyticus, people with V. vulnificus, could experience chills, abnormally low blood pressure or, bacteria present in the blood. These symptoms are of greatest concern for vulnerable individuals.

The illness can last up to three days, and severe illness is rare. Treatment is rarely needed, other than to drink plenty of fluids, including fruit juice and electrolytes. People most at risk for complications are pregnant women, people with weakened immune systems, young children and the elderly.

Cholera is a much more serious illness. People with V. cholerae usually develop one or more of the following symptoms one to three days after being infected:

  • diarrhea (watery)
  • leg cramps
  • vomiting
  • dehydration
  • low blood pressure

People with cholera can experience a wide range of symptoms. Some do not get sick at all and others feel as though they have a bad case of diarrhea. Still others become seriously ill and must be hospitalized.

Cholera can last up to seven days. Because of the rapid loss of body fluids, cholera can lead to dehydration and shock. The main treatment is rehydration with fluids, particularly saline or electrolytes, either orally or through intravenous (IV) injections. In serious cases, an antibiotic is administered. Without treatment, death can occur within hours, and the death rate can reach as high as 50 percent in regions where sanitary conditions are poor. With treatment, the death rate can be reduced to about 1 percent.

Like most foodborne illnesses, people most at risk for complications are pregnant women, people with weakened immune systems, young children and the elderly.

How do I avoid getting sick

Food safety tip

For shellfish in the shell, either a) boil until the shells open and continue boiling for 5 more minutes, or b) steam until the shells open and then continue cooking for 9 more minutes. Do not eat those shellfish that do not open during cooking. Boil shucked oysters at least 3 minutes, or fry them in oil for at least 10 minutes at 375°F (190°C), while keeping the pieces well separated.

Foods contaminated with Vibrio species, look, smell and taste normal. These tips will help protect you and your family from infection with Vibrio species:

  • Drink water from a safe (treated or boiled) water supply.
  • Buy shellfish from reputable suppliers.
  • Cook shellfish thoroughly before eating, especially oysters. Do not eat raw shellfish.
  • Cook food to a safe internal temperature and use a digital thermometer to check.
  • Eat shellfish right away after cooking and refrigerate leftovers.
  • Always keep raw and cooked shellfish separate.
  • Avoid taking antacids prior to eating oysters, or other seafood, as reduced stomach acid may favour the survival and growth of Vibrio species.
  • When travelling to developing countries, drink water from a safe (treated or boiled) source. Eat only cooked hot food. Eat only fruit that can be peeled.
  • 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.

These safe food practices will reduce your risk of getting sick from vibrios and other foodborne illnesses.

What does the Government do to protect me?

In Canada, several government organizations work together every day to keep your food safe:

  • Health Canada prepares and develops food safety standards and policies using science-based surveillance and monitoring of seafoods, harvested and sold in Canada, to help minimize the risk of foodborne illnesses.
  • The Canadian Food Inspection Agency (CFIA) enforces these policies and standards and carries out inspections to make sure the food industry meets its food safety responsibilities. The CFIA works with Health Canada to make sure that foodborne illness is detected early and warnings go out to the public quickly.
  • The Public Health Agency of Canada studies the incidence and causes of diseases in Canada, conducts outbreak surveillance, and coordinates outbreak response.

The Government of Canada works very hard to protect your health and safety:

  • We are carrying out a five-year Food and Consumer Safety Action Plan, to strengthen and modernize Canada's safety system and make sure you can have confidence in the quality and safety of the food, health and consumer products you buy.
  • We are investing in Canada's food safety system by enhancing food safety in areas such as prevention, early detection, active surveillance and effective response and communication with Canadians.
  • We support and participate in public awareness campaigns about safe food practices, like the Canadian Partnership for Consumer Food Safety Education's Be Food Safe program, which encourages Canadian consumers to think of food safety at every step of the food handling process, from shopping for groceries to re-heating leftovers.
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