Three Canadians diagnosed with botulism in France – what to know about illness

The illness is spread primarily by eating or drinking products contaminated with a dangerous toxin.

This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis or treatment. Contact a qualified medical professional before engaging in any physical activity, or making any changes to your diet, medication or lifestyle.

Botulism is a rare foodborne disease caused by bacteria called Clostridium botulinum. (Photo by: CAVALLINI JAMES/BSIP/Universal Images Group via Getty Images) Clostridium botulinum or botulinum bacillus is a bacterium that secretes botox, a toxin that inhibits the neurons responsible for muscle contraction. By localized injection, the toxin reduces wrinkles by paralyzing the muscles causing wrinkles. Colorization and HDRI treatments on X 1000 optical microscopy. (Photo by: CAVALLINI JAMES/BSIP/Universal Images Group via Getty Images)
Botulism is a rare foodborne disease caused by bacteria called Clostridium botulinum. (Photo by: CAVALLINI JAMES/BSIP/Universal Images Group via Getty Images)

The Public Health Agency of Canada says three Quebecers have become ill in a botulism outbreak in France that lead to one death (not Canadian).

All individuals ate at the same restaurant, called Tchin Tchin Wine Bar in a touristy area of Bordeaux, France, according to the agency's notice.

"Sardines prepared by and served at the restaurant are suspected to be the source of illness," public health said, adding the exposures occurred from Sept. 4-10. It also warned there may be "additional cases identified among Canadians travelling in France who consumed a meal at this restaurant."

Symptoms of botulism can take over a week to begin, so PHAC advised any such travellers to "self-monitor for symptoms, and seek immediate medical care if they develop symptoms."

The Public Health Agency of Canada says three Canadian residents have fallen ill from a botulism outbreak in Bordeaux, France. They're among 10 people who have suspected botulism after eating sardines prepared and served at Tchin Tchin Wine Bar. The Tchin Thin wine bar is seen in Bordeaux, southwestern France, Thursday, Sept.14, 2023. THE CANADIAN PRESS/AP-Sophie Garcia
The Public Health Agency of Canada says three Canadian residents have fallen ill from a botulism outbreak in Bordeaux, France. THE CANADIAN PRESS/AP-Sophie Garcia

Botulism can cause serious illness and even hospitalization. But what exactly does it do?

Read on for everything you need to know.

What is botulism and what causes it?

Botulism is a rare food-borne disease caused by botulinum toxin, produced by bacteria called Clostridium botulinum.

"Botulinum toxin is the most potent toxin known," according to Health Canada Research Scientist, Dr. John Austin, who added that because botulism is "so dangerous," early intervention is key.

The illness is spread primarily by eating food or drinking beverages contaminated with the toxin, PHAC said.

According to PHAC, some common sources include:

  • Home-canned foods such as beets, peppers, asparagus, mushrooms and green beans

  • Stored food products such as oil or garlic in oil (garlic confit), onions sautéed in butter, commercially prepared chilli and cheese sauce, baked potatoes stored in aluminum foil at room temperature

  • Fish or marine mammal meat, including seal, whale, walrus, salmon eggs and smoked or salted ungutted fish that is not refrigerated

"Food and beverages become contaminated when spores of the bacteria that cause botulism get into these products where they grow and produce toxins."

Row of canned vegetables in 19th century style canning jars with paper tops
Canned goods and other sealed food products provide ideal conditions for bacteria growth. (Getty)

It cannot be spread person-to-person, however public health warns it can come from the injection of illicit drugs. Wound botulism is "very rare and has never been reported in Canada," PHAC said, but it has been increasingly reported in other countries among injection drug users.

Infant botulism also rare in Canada, and occurs when children under the age of one accidentally consume the spores of the bacteria. The only known culprit to date is honey which is contaminated with the spores, not the toxin.

"Canned goods and other sealed food products provide ideal conditions for bacteria growth," the health agency explained, but assures commercial canned foods are generally safe. "Commercial canned foods are processed at a high temperature to kill bacteria. These foods have an exceptionally good safety record."

What are the symptoms of botulism?

Symptoms of the illness can take eight days to begin, though they usually appear within 72 hours of eating or drinking the contaminated item, according to public health.

They can include the following:

  • nausea, diarrhea and vomiting

  • dry mouth and difficulty swallowing

  • constipation

  • blurred or double vision

  • drooping eyelids and unreactive or fixed pupils

  • difficulty speaking, including slurred speech

  • partial facial paralysis or loss of facial expression

  • a change in sound of the voice, including hoarseness

In infants, it can also include nausea and vomiting, in addition to irritability, a weak cry, poor feeding, loss of head control and muscle weakness from the head down.

What to do if you become ill?

Testing for botulism can include stool, blood, and stomach contents, as well as suspicious foods. (Getty)
Testing for botulism can include stool, blood, and stomach contents, as well as suspicious foods. (Getty)

Public health advises contacting your doctor should you or your child experience symptoms of botulism so that you can be referred to laboratory testing.

Testing generally includes samples of stool, blood, and stomach contents, as well as suspicious foods.

Treatment for the illness will likely include hospitalization and supportive medical care. It could also include a medication that blocks the botulinum toxin, called the botulism antitoxin.

"Most people recover from botulism, if diagnosed and treated quickly," public health claimed. "However, recovery can take several weeks to months."

How to stay safe?

Botulism is very rare in Canada, and there is currently no vaccine against it. However, there are measures you can take to help prevent contamination.

Refrigerating leftovers immediately, keeping oil-stored foods in the fridge, making sure all foods that say 'keep refrigerated' are being so, and learning about home canning safety can help, PHAC advised.

"Never eat food from cans that are dented, bulging or leaking. This could mean the contents are contaminated and may not be safe to eat," it added.

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