Botulism is a rare but serious paralytic illness caused by botulinum toxin, which is produced by the Clostridium botulinum. This toxin is the most poisonous substance known. It 100 000 times more toxic than sarin gas. Eating or breathing this toxin causes illness in humans. Four distinct clinical forms are described: foodborne, wound, infant and intestinal botulism. The fifth form, inhalational botulism, is caused by aerosolised botulinum toxin that could be used as a biological weapon. A deliberate release may also involve contamination of food or water supplies with toxin or C. botulinum bacteria. By inhalation, the dose that would kill 50% of exposed persons (LD50) is 0.003 microgrammes/kg of body weight. Patients with respiratory failure must be admitted to an intensive care unit and require long-term mechanical ventilation. Trivalent equine antitoxins (A,B,E) must be given to patients as soon as possible after clinical diagnosis. Heptavalent human antitoxins (A-G) are available in certain countries.
Keywords: botulism.