botulism /boch″əliz′əm/ [L, botulus, sausage] , an often fatal form of food poisoning caused by an endotoxin produced by the bacillus Clostridium botulinum. In the United States, approximately 25% of cases are food-borne botulism, 72% are infant botulism, and the rest are wound botulism. In food-borne botulism, the toxin is ingested in food contaminated by C. botulinum, although it is not necessary for the live bacillus to be present if the toxin has been produced. In infant botulism, which is associated with eating unpasteurized honey, infants may consume pores that produce the toxin. In wound botulism, the toxin may be introduced into the human body through a wound contaminated by the organism. Botulism differs from most other types of food poisoning in that it develops without gastric distress and occurs 18 hours up to 1 week after the contaminated food has been ingested. Botulism is characterized by lassitude, fatigue, and visual disturbances, such as double vision, difficulty in focusing the eyes, and loss of ability of the pupil to accommodate to light. Muscles may become weak, and dysphagia often develops. Nausea and vomiting occur in fewer than half the cases. Affected infants are lethargic, feed poorly, are constipated, and have a weak cry and poor muscle tone. Hospitalization is required, and antitoxins are administered. Sedatives are given, mainly to relieve anxiety. Approximately 8% of the cases of botulism are fatal, usually as a result of delayed diagnosis and respiratory complications. Most botulism occurs after eating improperly canned or cooked foods. Reporting botulism to public health authorities is mandatory. See also Clostridium. ▪ OBSERVATIONS: Symptoms usually appear 18 to 36 hours after ingestion of a contaminated food substance. Severity of symptoms is related to the quantity of the botulinum toxin that was ingested and include dry mouth, diplopia, loss of pupillary light reflex; nausea, vomiting, cramps, and diarrhea, which precede dysphagia, dysarthria, and progressive descending muscular paralysis. Botulism is fatal in about 8% of cases, usually because of respiratory paralysis or circulatory failure. Serum may be positive for botulinal toxins, and cultures may be taken of stomach contents, feces, or suspected food to confirm the causative organism. ▪ INTERVENTIONS: The trivalent botulinal antitoxin is administered as soon as possible after onset and clinical diagnosis. The GI tract is purged using laxatives, gastric lavage, and high colonic enemas to dilute and decrease absorption of the toxin. Tracheostomy and mechanical ventilation may be instituted if necessary. Care is supportive with a long recovery period and the need for rehabilitation to regain muscle tone, strength, and function. ▪ PATIENT CARE CONSIDERATIONS: Health care providers should be alert to signs and symptoms of serum sickness that frequently occur after the administration of the antitoxin, including fever, arthralgia, lymphadenopathy, skin eruption, pain, pruritus, and erythematous swelling at the injection site. Individuals may also report joint and muscle aches, chest pain, and difficulty breathing. The care of the health care team for acute illness is largely supportive and involves airway management, prevention of aspiration, fluid and electrolyte management, pain management, nutrition management, prevention of skin breakdown and contractures during paralysis, minimization of stimuli, precise communication because of altered vision and loss of speech, and allaying anxiety about paralysis and treatment. Primary prevention targets education of consumers in the safe handling, storage, and preparation of food. Health professionals should also be prepared for an effective response should botulinum toxin be used in a bioterrorism event. This includes familiarization with institution policies, procedures, and protocols and maintenance of current knowledge regarding bioterrorism threats.
