Botulism, a potentially fatal neuroparalytic illness, has been recognized since the 18th century. It results from botulinum neurotoxin (BoNT), the most potent toxin known, which is produced by Clostridium botulinum and other Clostridium species. The toxin interferes with release of acetylcholine from presynaptic motor and autonomic nerve terminals, thereby disrupting neuromuscular transmission and autonomic synapses, resulting in flaccid paralysis and autonomic dysfunction. In adults, most cases are foodborne, resulting from ingestion of toxin, while most cases in infants result from ingestion of bacterial spores which proliferate and produce toxin in the gastrointestinal tract. Less common forms of botulism include wound botulism, in which spores are inoculated into a wound and locally produce toxin, and inhalational botulism due to aerosolized BoNT, potentially used as a weapon of bioterrorism. Therapeutic injections of BoNT may result in transient adverse effects, but serious sequelae are rare when BoNT is properly prepared and administered.
The earliest cases of botulism were described in Europe in 1735 and were attributed to improperly preserved German sausage; the name of the disease alludes to this association, botulus being Latin for sausage. Emile van Ermengem identified the causative organism in 1897 and named it Bacillus botulinum; it was later renamed Clostridium botulinum.25 These Gram-positive, spore-forming bacteria produce seven serotypes of BoNT, denoted A through G. All clostridial species are ubiquitous, and the bacteria and spores are present in soil, seawater, and air.130 Botulism outbreaks can occur anywhere in the world118 and have been reported from such diverse areas as Iran,106 Japan,100 Thailand,73 France,1 Portugal,77 and Canada.94
In 2007, a total of 144 cases of botulism were reported to the Centers for Disease Control and Prevention (CDC). Foodborne botulism constituted 18% of cases, infant botulism 63% of cases, and wound botulism 15%.42 In this analysis, toxin type A accounted for the majority of cases of both foodborne (58%) and wound (82%) botulism, while infant botulism was due to toxin type A in 43% and to toxin type B in 56% of cases.42 Six deaths were confirmed: three in patients with foodborne botulism and three in patients with wound botulism. The case fatality rate has improved for all botulism toxin types, probably due to increasing awareness of the problem and consequent earlier diagnosis, appropriate and early use of antitoxin, and better and more accessible life support techniques.
In the last 50 years, home-processed food has accounted for 65.1% of outbreaks, with commercial food processing constituting only 7% of reported cases; in the other 27.9% of outbreaks the origin remains unknown.38 Common home-canning errors responsible for botulism include failure to use a pressure cooker and allowing food to putrefy at room temperature. Minimally processed foods such as soft cheeses may lack sufficient quantities of intrinsic barriers to BoNT production, such as salt and acidifying agents.112 These foods become high-risk sources of botulism when refrigeration standards ...