Botulism is a very rare medical emergency. It is not an infection, but an intoxication (that is, the result of introduction of a toxic substance). Anaerobic spores of Clostridium botulinum produce this poison, but it is not necessary to be infected with these spores to become ill (although that sometimes happens). Food borne botulism (the type encountered in this episode) usually comes from use of inadequately cooked food. The toxin is quite deadly, about a million times more so than strychnine, but modern supportive care as over the years since this episode aired vastly reduced the number of lethal cases. After effects can linger for months or in some cases years, most commonly shortness of breath.