Botulism (food-borne botulism and infant botulism)

Last Reviewed: October 2011

What is botulism?

Botulism is a serious illness caused by a nerve toxin made by the bacterium, Clostridium botulinum (C. botulinum). A toxin is a poison that is released by some bacteria. There are three types of botulism: food, wound and infant botulism. Eating food that has the botulism toxin causes food-borne botulism. It often involves improperly processed home canned foods. Wound botulism occurs when C. botulinum spores contaminate a wound and produce toxin. Botulism in infants under one year of age has been associated with ingestion of C. botulinum spores from the environment or specific foods such as honey.

Can botulism be used as a bioterrorism threat?

In the event of a bioterrorism event, people intentionally exposed who breathe in the toxin or eat the toxin in contaminated food or water might develop the illness. People who breathe in the botulinum toxin may have similar symptoms to those with foodborne botulism.

How is it spread?

Botulism is most often caused by bacteria that have produced the toxin in a wound or in food. Person-to-person spread does not occur.

What are the symptoms?

All types of botulism produce symptoms that affect the nervous system. The classic symptoms of botulism include double vision, blurred vision, drooping eyelids, slurred speech, difficulty swallowing, dry mouth and muscle weakness that goes down the body, first the shoulders, then upper arms, lower arms, thighs, calves, feet. If untreated these symptoms may progress to paralysis. Infants with botulism appear lethargic, feed poorly, are constipated, have a weak cry and poor muscle tone.

How soon after exposure would symptoms develop?

Symptoms generally begin 12-36 hours after eating contaminated food, but may occur as early as a few hours and as late as 10 days. Symptoms of botulism in infants may occur up to 14 days later.

Can I spread this to my family?

No, this cannot be spread from person to person.

What is the treatment?

The symptoms of botulism make hospitalization necessary. If diagnosed early, botulism can be treated with an antitoxin, which blocks the action of the toxin circulating in the blood. This can prevent patients from worsening, but recovery still takes many weeks. If left untreated, a patient may need to be on a breathing machine (ventilator) for weeks and would require intensive medical and nursing care. Infant botulism is treated with immune globulin, which is similar to the antitoxin. Most cases of botulism recover with appropriate medical care.

If I develop symptoms, what do I do?

If you should develop any of the symptoms above, please contact your physician or your local hospital immediately for evaluation. Please keep any contaminated food for testing.

Can botulism be prevented?

All canned and preserved foods should be properly processed and prepared. Persons who do home canning should follow strict hygienic procedures to reduce contamination of foods. Because the botulism toxin is destroyed by high temperatures, persons who eat home-canned foods should consider boiling the food for 10 minutes before eating it to ensure safety. Bulging containers should not be opened and foods with an unusual smell should not be eaten or even tasted. Canned food with bulging lids should be thrown away. Identified sources of infant botulism, such as honey, should not be fed to infants under 1 year old.