Botulism occurs worldwide, but the number of cases reported varies among countries and regions. The variation may be due not only to actual differences in incidence but also to (1) availability of resources to identify botulism, a rare disease; (2) differences in reporting requirements; and (3) limited external access to data collections. There is no universal surveillance system to capture worldwide botulism incidence. However, 30 countries currently participate in voluntary reporting of botulism cases to the European Union through an established surveillance system that includes standardized case definitions similar to those used in the United States and Canada. Other countries (e.g., Argentina, China, Thailand, Japan) maintain independent botulism surveillance.
From 1899 to 2011, 1225 food-borne botulism events (single cases or outbreaks) were reported in the United States; from 1990 to 2000, a median of 23 cases were reported annually. Most such events (~80%) involve vegetables or fish/aquatic animals, usually home-preserved (canned, jarred). Native communities in both the United States (Alaska) and Canada have a high incidence of food-borne botulism due to traditional food-preparation practices; 85% of all cases in Canada occur in Native communities. Outbreaks typically involve two or three cases; however, one restaurant-associated outbreak in 1977 affected 59 persons. Worldwide, the highest incidence rate is reported from Georgia and Armenia in the southern Caucasus region, where illness is also associated with home-canning practices. Outbreaks in Asia are attributable to consumption of home-preserved fish or vegetable products such as bean curd and bamboo shoots. In parts of Europe, including Poland, France, and Germany, illness is often associated with home-preserved meat such as ham or sausage. Since 1950, commercial products have rarely been implicated in botulism in the United States, and botulism from commercial products is most often attributed to consumer error in storage or cooking. However, manufacturer deficiencies do occur. In 2007, botulism developed in eight persons in the United States who consumed a commercially canned hot-dog chili sauce. Significant deficiencies discovered by regulatory authorities involved 91 different products and resulted in the recall of 111 million cans of food.
This form of disease was first recognized in 1951 as a result of a review of the clinical records on an accidental injury in 1943. Between 1943 and 2011, 491 cases of wound botulism were reported in the United States; 97% of cases reported after 1990 were associated with injection drug use. The typical patient was a 30- to 50-year-old resident of the western United States with a long history of black-tar heroin injection. In the early 2000s, wound botulism associated with drug use emerged in Europe, and at least two case clusters have been reported.
More than 3900 infant botulism cases have been reported worldwide (84% in the United States alone) since this form of the disease was first recognized in 1976; ~80–100 cases (commonly caused by serotypes A and B) are reported annually in the United States.
Adult intestinal colonization botulism
This form of botulism is difficult to confirm because it is poorly understood and because no clear guidelines are available to help differentiate it from other adult botulism cases. Often these cases are caused by C. baratii type F, but the involvement of both C. botulinum type A and C. butyricum type E has been reported.
Paralysis of variable severity has followed injection of licensed botulinum toxin products for treatment of conditions involving hypertonicity of large muscle groups. The U.S. Food and Drug Administration received 658 reports of adverse events related to botulinum toxin use—some very serious—between 1997 and 2006. Although some patients had symptoms consistent with botulism, no cases were laboratory confirmed. Injection of approved doses of licensed products for cosmetic purposes has not been associated with botulism. However, four cases of laboratory-confirmed botulism resulted from illegal injection of research-grade toxin for cosmetic purposes in a U.S. medical facility in 2004.
Inhalational botulism does not occur naturally. One report from Germany has described botulism resulting from possible inhalational exposure to botulinum toxin in a laboratory incident.
Botulinum toxin has been “weaponized” by governments and terrorist organizations. An attack might use aerosolization of toxin or contamination of foods or beverages ranging in scope from small-scale tampering to contamination of a widely distributed food item. An unnatural event may be suggested by unusual relationships between patients (e.g., a visit to the same building), atypical exposure vehicles, or atypical toxin serotypes.