How common is botulism


Pathogen and transmission

Botulism is caused by toxins (botulinum toxins). These are produced by the bacterium Clostridium botulinum. Botulism is therefore poisoning and cannot be transmitted from person to person. Poisoning with botulinum toxins occurs in most cases after ingestion of spoiled food, but it can also be the result of inadequate wound disinfection. Botulinum toxins are among the most potent poisons known; less than 1 millionth of a gram of type A is enough to kill a person weighing 70 kg.

Clinical picture

In the case of food botulism, headaches, dry mouth, eye muscle paralysis, hoarseness, difficulty swallowing and paralysis occur after 12 to 36 hours and in wound botulism after 4 to 14 days. The paralysis of the respiratory muscles can lead to death by suffocation. In the case of botulism, only the symptoms can be alleviated. In the early stages of poisoning, medical treatment with botulinum antitoxin can be helpful. Thanks to the treatment options of modern medicine, the fatal courses have dropped to 5 to 10% of all cases.

Distribution and frequency

Clostridium botulinum only thrives in an oxygen-free environment. It occurs worldwide in the earth, sea and ocean floors and can survive for a long time in the form of resistant spores. Botulism occurs very rarely in Switzerland with one or two cases per year.


As a preventive measure, canned food should not be eaten from cans with a curved lid or from leaky mason jars. No vaccine against botulism is available in Switzerland.

Botulism poisoning is monitored by the Federal Office of Public Health. Due to the widespread occurrence of Clostridium botulinum, the enormous potency of its toxins, and the severe symptoms of intoxication, there is a risk that botulinum toxins could be used for biochemical weapons.

Reporting requirement

For food botulism, there is a 2-hour reporting requirement. Doctors who suspect food botulism are obliged to report this immediately to the canton doctor and the FOPH. This measure is mainly used to quickly identify the contaminated food source and to prevent further cases of poisoning. There is no longer an obligation to report for wound and infant botulism.


People who at C. botulinum are ill and have the symptoms mentioned require intensive care and can be treated with botulinum antitoxins within the first few days after the first symptoms appear. In Switzerland, botulinum antitoxins can be requested from the army pharmacy.