What is botulism?

Botulism is a rare, but very serious illness that causes difficulty breathing, muscle paralysis and sometimes death. Botulism occurs when a toxin is released by a bacteria called Clostridium botulinum that attacks the nervous system. Only a small amount of toxin is needed to cause illness. Botulism can be found in soil where it can survive due to its protective shell. When food contaminated with C. botulinum is canned or vacuumed sealed, the bacteria are able to grow and produce a toxin because of the low oxygen level. All forms of botulism can be fatal and are considered medical emergencies.

How is botulism spread?

Botulism can be spread in three ways:

  • Food-borne botulism occurs when food containing the toxin is eaten.
  • Intestinal (infant and adult colonization) botulism occurs when food containing the C. botulinum spores is eaten and then grows in the intestines, where the toxin is produced and released. Children under one year of age and adults who have bowel abnormalities are not able to clear the C. botulinum spores from their bodies naturally, unlike most adults and children over one year of age.
  • Wound botulism occurs when a wound is infected with C. botulinum spores and the toxin is released and causes illness.
What are the symptoms of botulism?

Symptoms of food-borne botulism can include:

  • fatigue, weakness and dizziness
  • blurred or double vision
  • dryness in the mouth, difficulty swallowing or slurred speech
  • headache
  • nausea, vomiting, abdominal pain and, less commonly, diarrhea and constipation
  • paralysis that starts in the shoulders and arms and moves down the body

Symptoms of infant botulism can include:

  • constipation
  • weakness, a weak cry or poor sucking reflex
  • irritability
  • lack of facial expression, loss of head control or poor muscle tone
  • trouble breathing due to paralysis of the breathing muscles

Symptoms of food-borne botulism generally begin 12 to 36 hours after ingesting contaminated food, however, can be as short as 6 hours or as long as 10 days later. All forms of botulism can lead to paralysis of the breathing muscles, respiratory or heart failure and death.

Is there a treatment for botulism?

If the illness is recognized and diagnosed early, it can be treated with antitoxin, which will stop the disease from becoming worse. Early medical treatment is critical to reduce the risk of complications and death.

How can I protect myself from botulism?

There are several ways that you can protect yourself and others from botulism:

  • Prepare and can food safely. For more information on safe home canning,  see the Food Safety Tips for Home Canning information available online from Health Canada.
  • Refrigerate foods stored in oil (vegetables, oils containing garlic or herbs)
  • Avoid feeding honey to infants less than one year of age
  • Do not eat canned or bottled foods if the container is dented, leaking, or bulging
  • Follow the guidance on food labels for shelf-life
  • Seek prompt medical care for infected wounds
  • Practice safe injection techniques to decrease the risk of abscesses
What is Ottawa Public Health's role?

Ottawa Public Health (OPH) must be notified by health care providers and laboratories when a person is diagnosed with botulism. OPH conducts an investigation to determine the potential cause or source of the infection, provide education to the infected person and their close contacts, and follows up with the infected person’s health care provider, as needed.


Contact Us