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[botul(in) + -ism]
A paralytic, occasionally fatal illness caused by exposure to toxins released from Clostridium botulinum. In adults, the disease usually occurs after food contaminated by the toxin is eaten, after gastrointestinal (GI) surgery, or after the toxin is released into an infected wound. In infants (usually between 3 and 20 weeks), the illness results from intestinal colonization by clostridial spores (perhaps related to honey or corn syrup ingestion), then production of the exotoxin within the intestine. Because the toxin is extraordinarily lethal and easy to manufacture and distribute, concern has been raised regarding its use as an agent of biological warfare.
SEE: Clostridium botulinum
Approx. 100 cases of botulism are reported in the U.S. each year.
Foodborne botulism may result from consumption of improperly cooked or canned meals in which the spores of the bacillus survive and reproduce. Wound botulism may begin in abscesses, where an anaerobic environment promotes the proliferation of the bacterium and absorption of its poison. In either case, cranial nerve paralysis and failure of the autonomic and respiratory systems may occur; gastrointestinal symptoms are likely to occur only in foodborne outbreaks.
The poison responsible for botulism damages the nervous system by blocking the release of acetylcholine at the neuromuscular junction. This is the cause of the paralysis associated with the illness.
SYMPTOMS AND SIGNS
Nausea, diarrhea, vomiting, ptosis, double vision, slurred speech, and swallowing difficulties are all common symptoms in adults. Constipation, poor feeding, and flaccidity (floppy baby syndrome) may occur in children. The spectrum of illness is broad; some patients suffer other complications, including generalized paralysis and respiratory failure, the usual causes of death (25% mortality).
Positive results of serum levels, gastric contents, stool, suspected food cultures for botulinum toxin, or a positive mouse inoculation test (using samples from suspected food sources) will make the diagnosis in patients in whom other neurological evaluations are negative. Because the clinical presentation is similar to stroke and Guillain-Barré and Eaton-Lambert syndromes, neural imaging and spinal fluid analysis are generally performed; results are negative in botulism.
Trivalent antitoxin (ABE), an antitoxin made from horse serum, should be administered intravenously (IV) or intramuscularly (IM) early in patients suspected of having botulism, which decreases mortality and morbidity associated with the illness. Botulinum antitoxin is available from the Centers for Disease Control and Prevention by calling (404) 639-2206 (daytime) or (404) 639-2888 (evening).
Patients who have ingested tainted foods may benefit from GI decontamination (lavage and enema to remove unabsorbed toxin). IV fluids provide hydration. Very close monitoring of affected patients, preferably in intensive care units, is indicated so that prompt intubation and mechanical ventilation can begin if respiratory failure develops. Vital signs, respiratory effort, and respiratory distress are documented and reported. Arterial blood gases are monitored. Neuromotor function is carefully and repeatedly assessed. Before botulinum antitoxin is administered, a history of the patient's allergies, esp. to horse serum, is obtained and a skin sensitivity test performed. After antitoxin administration, the patient must be closely watched for anaphylaxis. Subcutaneous epinephrine 1:1,000 and airway equipment should be readily available for such an emergency. Other hypersensitivity reactions and serum sickness may also occur.
If relatives or other close contacts of the patient have eaten similar foods or have shown similar symptoms, they should be carefully examined and treated: botulism is a reportable illness in every state in the U.S. Health care professionals can help prevent botulism by explaining proper food processing and preserving techniques. Food obtained from a bulging container or food with a peculiar odor should always be avoided.