Botulism

BOTULISM

Botulism is a rare disease that occurs in four forms: food-borne botulism (the most common form); infant botulism (sometimes associated with honey); an adult form of infant botulism; and wound infection botulism. Botulism is caused by botulinum neurotoxin, which blocks acetylcholine release at neuromuscular junctions, resulting in paralysis. The toxin is produced under anaerobic conditions by Clostridium botulinum, a bacterium found widely in the environment.

In food-borne botulism, the preformed toxin is ingested. There are two main bacterial strains: Group I strains are proteolytic, have spores that are highly resistant to heat, and cannot grow below 10°C. Group II strains are nonproteolytic, are less likely to survive thermal processing or grow in acid or salty products, and grow at refrigeration temperatures. The canning industry has developed retort conditions to prevent the survival of all spores.

Symptoms of food-borne botulism include double vision, inability to speak or swallow, labored breathing, and death. Food-borne botulism can be caused by improperly processed or stored foods, including vegetables, meat, fish, and cheese. The annual incidence of botulism is highest in Russia, Poland, and Hungary with 0.2 to 0.3 cases per 100,000 persons (due to contaminated home-preserved foods); and in the Innuit populations of Canada and Alaska (60 cases per 100,000 persons in northern Quebec), where it is usually associated with toxins in putrefied whale, seal, or fish products.

Symptoms of infant botulism include constipation, weakness, and respiratory arrests, but rarely death.

EWEN TODD

(SEE ALSO: Food-Borne Diseases)

BIBLIOGRAPHY

Austin, J. W., and Dodds, K. L. (2001). "Clostridium botulinum." In Food-borne Disease Handbook, 2nd edition, eds. Y. H. Hui, M. D. Pierson, and J. R. Gorham. New York: Marcel Dekker.

Center for Food Safety and Applied Nutrition. Clostridium botulinum. In Bad Bug Book (Food-borne Pathogenic Microorganisms and Natural Toxins Handbook). Washington, DC: Center for Food Safety and Applied Nutrition U.S. Food and Drug Administration. Available at http://vm.cfsan.fda.gov/~mow/chap2.html.