Botulism is a rare but serious illness caused by the bacterium Clostridium botulinum. The bacterium may enter the body through wounds, or they may live in improperly canned or preserved food.

Causes, incidence, and risk factors

Clostridium is found in soil and untreated water throughout the world. It produces spores that survive in improperly preserved or canned food, where they produce toxin. When eaten, even minute amounts of this toxin can lead to severe poisoning.

The foods most commonly contaminated are home-canned vegetables, cured pork and ham, smoked or raw fish, and honey or corn syrup. Botulism may also occur if the organism enters open wounds and produces toxin there.

Infant botulism is a special type in which living bacteria or its spores are ingested and grow within the infant’s gastrointestinal tract. The most common cause of infant botulism is ingestion of honey or corn syrup.

Clostridium also occurs normally in the stool of some infants.

Approximately 110 cases of botulism occur in the U.S. per year. The majority are in infants. Respiratory failure caused by weakness in the muscles that control breathing can cause death in up to 7% of food-related illness.


  • difficulty swallowing and speaking  
  • progressive weakness with paralysis  
  • nausea, vomiting  
  • abdominal cramps  
  • dry mouth  
  • double vision  
  • breathing difficulty that may lead to respiratory failure  
  • breathing, absent temporarily  
  • no fever, usually  
  • in infants:       o constipation       o weakness, loss of muscle tone       o weak cry       o poor feeding and weak sucking       o respiratory distress       o appears alert but weak

Note: Symptoms usually appear between 8 to 36 hours after consuming contaminated food.

Signs and tests

  • speech impairment  
  • muscle function/feeling loss  
  • eyelid drooping  
  • absent or decreased gag reflex  
  • absent or decreased deep tendon reflexes  
  • paralyzed bowel  
  • severe constipation  
  • urine retained in bladder with inability to urinate  
  • blood test to identify toxin  
  • laboratory analysis of suspected food  
  • stool culture


Emergency hospitalization is recommended in cases of respiratory trouble. The goal of treatment is to establish a clear airway, aid breathing, give botulinus anti-toxin, and provide supportive therapy.

If breathing difficulty develops, intubation (a tube inserted through the nose or mouth into the trachea to provide an airway for oxygen) and mechanical ventilation are given. Intravenous fluids can be given while swallowing difficulties persist. Also, a feeding tube may be inserted in the nose.

Occurrences of the disease are reported to state health authorities or the CDC (Centers for Disease Control and Prevention) by health care providers so that contaminated food can be removed from stores. Antibiotics are often given, but have not been shown to always be beneficial.

Expectations (prognosis)
Prompt treatment significantly reduces the risk of death.


  • aspiration pneumonia and infection  
  • respiratory distress  
  • long-lasting weakness  
  • nervous system dysfunction for up to one year

Calling your health care provider
Go to the emergency room or call the local emergency number (such as 911) if botulism food poisoning is suspected.


  • Do not give honey or corn syrup to infants who are younger than 1 year old. (Not even just a little taste on a pacifier.)  
  • Always discard bulging cans or off-smelling preserved foods. Sterilize home canned foods by pressure cooking at 250 degrees Fahrenheit for 30 minutes.  
  • Keep foil-wrapped baked potatoes hot or in the refrigerator, not out in room temperature.  
  • Breast-feeding can help prevent infant botulism.


Johns Hopkins patient information

Last revised: December 7, 2012
by Sharon M. Smith, M.D.

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