Botulism

Clostridium botulinum is the name of a group of bacteria commonly found in soil. These bacteria produce spores that are able to survive in a dormant state until more favorable conditions allow them to grow. Botulism is a rare but serious muscle-paralyzing disease caused by the nerve toxins (poisons) made by these bacteria. The bacteria spores or toxin may enter the body through wounds, by consupmtion or inhalation. Small amounts of the toxin can lead to severe illness.

There are three main kinds of botulism:

1. Foodborne botulism occurs when a person ingests the toxin-contaminated food, which leads to illness as early as 6 hours or as late as 8 days (generally 12 - 48 hours) after exposure . A common cause of this illness is improperly preserved home-processed foods with low acid content, such as green beans, beets, and corn. Less likely sources include fish products and other commercially processed foods. Foodborne botulism is a public health emergency because the contaminated food may still be available to other persons besides the patient.
2. Infant or Intestinal botulism occurs in a small number of susceptible individuals, especially infants when C. botulinum spores are consumed, which then grow in the person's intestines and produce toxins. The incubation period is thought to be 3 to 30 days from the time of exposure. A number of such cases have been associated with infants eating honey contaminated with C. botulinum spores.
3. Wound botulism occurs when wounds are infected with C. botulinum that secretes the toxin that is absorbed into the bloodstream. Symptoms of wound botulism may appear from 4 to 14 days from the time of injury. Wound botulism is associated with crush injuries and with illicit drug use.

The first symptoms of botulism may include:

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

Neurological symptoms always descend through the body; shoulders are first, then the upper arms, lower arms, thighs, calves and so on. Paralysis of breathing muscles can cause loss of breathing and death unless mechanical ventilation is provided.

Infants with botulism appear lethargic, feed poorly, are constipated, and have a weak cry and poor muscle tone. If untreated, these symptoms may progress to cause paralysis of the arms, legs, trunk and respiratory muscles.

Botulism can be prevented. Persons who do home canning should obtain instructions on safe home canning from county extension services or from the US Department of Agriculture. Because honey can contain spores of C. botulinum , children less than 12 months old should not be fed honey. Wound botulism can be prevented by promptly seeking medical care for infected wounds and by not using injectable street drugs.

Treatment of botulism will include careful observation, supportive care, and possibly the administration of antitoxin. CDC maintains a supply of antitoxin against botulism. Even after treatment, patients may still require weeks to months of supportive care, before they fully recovered.

Botulinum toxins, however, do have beneficial uses. Doctors use it to treat certain human diseases caused by muscle problems, such as strabismus (crossed eyes). It is also used to eliminate facial wrinkles.

Botulism as an Agent of Bioterrorism

The extreme toxicity of botulinum toxins and the ease of production, transport, and delivery make this an agent of extreme bioterrorism concern.