infectious diseases
Botulism
Sources of toxin
Home-canned foods, particularly low-acid foods (ie, pH > 4.5), are the most common sources of ingested toxin, but commercially prepared foods have been implicated in about 10% of outbreaks. Vegetables (but usually not tomatoes), fish, fruits, and condiments are the most common vehicles, but beef, milk products, pork, poultry, and other foods have been involved. Of outbreaks caused by seafood, type E causes about 50%; types A and B cause the rest. In recent years, foods that are not canned (eg, foil-wrapped baked potatoes, choppedgarlicin oil, patty melt sandwiches) have caused restaurant-associated outbreaks. Sometimes the toxin is absorbed through the eyes or a break in the skin and, in such cases, may cause serious disease. C. botulinumspores are common in the environment; most cases of infant botulism are caused by ingestion of spores, typically when honey is ingested. Spores can also enter the body when drugs are injected with unsterilized needles; wound botulism may result. Injecting contaminated black tar heroin into a muscle or under the skin (skin popping) is riskiest; it can cause gas gangrene as well as botulism. If botulinum toxins enter the bloodstream, botulism results, regardless of how the toxins are acquired. 