What is Botulism and how is it spread?

Botulism is a muscle-paralyzing disease caused by a toxin made by a bacterium called Clostridium botulinum, which is commonly found in soil.

There are several kinds of botulism, which are all considered medical emergencies:

  • Foodborne botulism occurs when a person ingests pre-formed toxin that leads to illness. Symptoms can begin within 6 hours or up to 2 weeks.
    • The bacteria grow best in food at room temperature (70° – 100°F).
    • Foodborne botulism is a public health emergency because the contaminated food may still be available to other persons besides the patient.
  • Infant botulism is the most-common form of botulism. It occurs in a small number of susceptible infants, usually between the ages of three weeks and six months, who ingest C. botulinum bacteria, which then grow in the intestines and release toxin.
  • Wound botulism occurs when wounds are infected with C. botulinum that secretes the toxin.

Botulism cannot be spread from one person to another.

What are the symptoms of Botulism?

The classic symptoms of botulism include:

  • Double vision
  • Blurred vision
  • Drooping eyelids
  • Slurred speech
  • Difficulty swallowing
  • Dry mouth
  • Muscle weakness

These symptoms are a result of muscle paralysis caused by the toxin. If untreated, symptoms may progress to cause paralysis of the arms, legs, truck and respiratory muscles.

How soon do symptoms appear?

Symptoms of foodborne botulism usually appear 18 – 36 hours after eating contaminated food. However, symptoms may develop as early as 6 hours or as late as 2 weeks.

Is there a treatment for Botulism?

Supportive hospital care is required. Untreated cases of botulism can result in death due to respiratory failure. However, in the past 50 years the proportion of patients with botulism who die has fallen from about 50 percent to 8 percent.

A patient with severe botulism may require a breathing machine as well as intensive medical and nursing care for several months.

Patients who survive an episode of botulism poisoning may have fatigue and shortness of breath for years and long-term therapy may be needed to aid recovery.

A supply of antitoxin against botulism is maintained by the CDC. The antitoxin is effective in reducing the severity of symptoms, if administered early in the course of the disease.

The botulism antitoxin is not recommended for cases of infant botulism.

How common is Botulism?

In the United States an average of 110 cases of botulism are reported each year. Of these, approximately 25 percent are foodborne, 72 percent are infant botulism, and the rest are wound botulism.

Outbreaks of foodborne botulism involving two or more persons occur most years and are usually caused by eating contaminated home-canned foods.

The number of cases of foodborne and infant botulism has changed little in recent years, but wound botulism has increased because of the use of black-tar heroin, especially in California.

Where can I get more information?

Additional information about botulism can be found on the Centers for Disease Control and Prevention’s website at www.cdc.gov.

Contact Information

(702) 759-1671

Updated on: December 21, 2021

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