Botulism overview

Botulism (Latin, botulus, "sausage") is a rare, but serious paralytic illness caused by a nerve toxin, botulin, that is produced by the bacterium Clostridium botulinum. Botulinic toxin is one of the most powerful known toxins: about one microgram is lethal to humans. It acts by blocking nerve function and leads to respiratory and musculoskeletal paralysis.

There are three main kinds of botulism:

• Foodborne botulism is caused by eating foods that contain the botulinum toxin.
• Wound botulism is caused by toxin produced from a wound infected with Clostridium botulinum. This is the rarest type of botulism.
• Infant botulism is caused by consuming the spores of the botulinum bacteria, which then grow in the intestines and release toxin.

All forms of botulism can be fatal and are considered medical emergencies. Foodborne botulism can be especially dangerous as a public health problem because many people can be poisoned from a single contaminated food source.

In the United States an average of 110 cases of botulism are reported each year. Of these, approximately 25% are foodborne, 72% are infant botulism, and 3% are wound botulism. Outbreaks of foodborne botulism involving two or more persons occur during most years and usually are 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. In July 2007, a widespread recall was initiated due to botulism contamination of food manufactured by Castleberry's Food Company. Shortly after in August 2007, the FDA issued a warning of botulism risk from canned French cut green beans manufactured by Lakeside Foods Inc, of Manitowoc, Wisconsin.

Botulinum toxin

Botulinum toxin blocks the release of acetylcholine from nerve endings thus arresting their function. The C. botulinum bacterium produces toxin in an anaerobic environment, and the toxin is unstable to heating, so poisoning generally occurs from the use of improperly bottled or canned foods: typical instances of botulism would be home-bottled preserves used in salads. An unusual example of botulism occurred in Britain in the exceptionally hot, dry summer of 1976, when river levels dropped so low in some areas that swans ingested material from anaerobic layers in a river (normally out of their reach), and were struck by botulism symptoms.

Botulinum toxin is used cosmetically to reduce facial wrinkles or excessive transpiration, and is commercially known as Botox. Cases of inadvertent botulism have occurred due to overdose or accidental intravenous injection of Botox.

Case study

On July 2, 1971, FDA released a public warning after learning that a New York man had died and his wife had become seriously ill due to botulism after eating a can of Bon Vivant vichyssoise soup. The company commenced a recall of the 6,444 cans of vichyssoise soup from the same batch. An effectiveness check of the recall revealed a number of swollen or otherwise suspect cans among Bon Vivant's other products, leading the FDA to question Bon Vivant's processing practices for all products. Five cans of soup were found to be contaminated with the botulin toxin, all from the batch initially recalled, and the FDA extended the recall to include all Bon Vivant products, and shut down the company’s Newark, New Jersey, plant on July 7, 1971. This destroyed public confidence in the Bon Vivant products, and the company filed for bankruptcy within a month.

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