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This fact sheet answers frequently asked questions about botulism.

Botulism is a rare but serious paralytic illness. It comes from a nerve toxin produced by bacteria called Clostridium botulinum.

The basics

What is botulism?

Botulism is a rare but serious paralytic illness. It comes from a nerve toxin produced by bacteria called Clostridium botulinum. There are three main kinds of botulism.

  • Food-borne botulism comes from eating foods that contain the botulinum toxin
  • Wound botulism comes from toxin produced by bacteria in an infected wound
  • Infant botulism comes from consuming the spore of the bacteria, which then grow in an infant’s intestines and release toxin

All forms of botulism can be fatal and are medical emergencies. Food-borne botulism is a public health emergency because contaminated food can lead to widespread illness.

How is botulism spread?

Naturally occurring botulism is most often spread through eating contaminated foods. However, if weaponized it can spread through the air or through contaminated food. It is not spread person to person.


What are the symptoms?

Symptoms include double vision, blurred vision, drooping eyelids, slurred speech, difficulty swallowing, and dry mouth. You may also experience muscle weakness that starts in the upper body and works its way down. People with botulism are usually alert and do not have a fever.

How long does it take for symptoms to appear?

The length of time it takes for symptoms to develop varies based on exposure. For food-borne botulism, symptoms can begin between 6 hours and 2 weeks after exposure, but most commonly begin between 12 and 36 hours.


How can I prevent botulism?

All canned and preserved foods should be properly processed and prepared. Do not open any bulging containers or jars. Do not eat any foods with off odors. Recognize sources of infantile botulism and avoid feeding things like honey to infants.


How is it treated?

Botulism is a very serious disease and can be fatal without medical treatment. Patients may need a ventilator for weeks to treat paralysis and respiratory failure. Patients may also need intensive medical and nursing care. Antitoxin can treat botulism if diagnosed early. Antitoxin blocks the action of the toxin circulating in the blood, and can lessen the severity of the illness. You must report all suspected botulism cases to the local health department. Report all suspected cases in Boston to the BPHC at 617-534-5611.

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