Table 18.1 Nomenclature of bone tumors
Botulism is an illness caused by a neurotoxin produced by Clostridium botulinum. Three types of disease can occur: foodborne botulism, wound botulism, and infant intestinal botulism. Recent concern has increased about a possible fourth type of disease: inhalational botulism. Does not occur naturally, but may occur as a result of bioterrorism.
Foodborne Botulism After ingestion of food containing toxin, illness varies from a mild condition for which no medical advice is sought to very severe disease that can result in death within 24 hours. The incubation period is usually 18-36 hours but, depending on toxin dose, can range from a few hours to several days. Symmetric descending paralysis is characteristic and can lead to respiratory failure and death. Cranial nerve involvement, which almost always marks the onset of symptoms, usually produces diplopia, dysarthria, dysphonia, and/or dysphagia. Weakness progresses, often rapidly, from the head to involve the neck, arms, thorax, and legs; occasionally, weakness is asymmetric. Nausea, vomiting, and abdominal pain may precede or follow the onset of paralysis. Dizziness, blurred vision, dry mouth, and very dry, occasionally sore throat are common. Patients are generally alert and oriented, but they may be drowsy, agitated, and anxious. Typically, they have no fever. Ptosis is frequent; the pupillary reflexes may be depressed, and fixed or dilated pupils are noted in half of patients. The gag reflex may be suppressed, and deep tendon reflexes may be normal or decreased. Sensory findings are usually absent. Paralytic ileus, severe constipation, and urinary retention are common.
Wound Botulism Wound botulism occurs when the spores contaminating a wound germinate and form vegetative organisms that produce toxin. This rare condition resembles food-borne illness except that the incubation period is longer, averaging about 10 days, and gastrointestinal symptoms are lacking. Wound botulism has been documented after traumatic injury involving contamination with soil; in injection drug users, for whom black-tar heroin use has been identified as a risk factor; and after cesarean delivery. The illness has occurred even after antibiotics have been given to prevent wound infection. When present, fever is probably attributable to concurrent infection with other bacteria. The wound may appear benign.
PHYSICAL FINDINGS & CLINICAL PRESENTATION
• Symptoms usually begin 12 to 36 hours following ingestion.
• Severity of illness is related to the quantity of toxin ingested.
• Significant findings:
1. Cranial nerve palsies, with ocular and bulbar manifestations being most frequent (diplopia, ophthalmoplegia, ptosis, dysphagia, dysarthria, and dry mouth)
2. Usually bilateral nerve involvement that may progress to a descending flaccid paralysis
3. Typically, absence of sensory findings; sensorium intact
4. GI symptoms (nausea, vomiting, diarrhea, or cramps)
5. Usually no fever
• Wound botulism
1. Occurs mostly in injecting drug users (subcutaneous heroin injection-“skin popping”) or with traumatic injury.
2. Presentation is similar to that of foodborne disease, except for a longer incubation period and the absence of GI symptoms.
3. Wound infection is not always apparent, but injection sites frequently reveal cellulitis, draining pus, or abscess formation.
• Cause is one of several types of neurotoxins (usually A, B, or E) produced by C. botulinum, an anaerobic, gram-positive bacillus. Spore production guarantees survival of the organism in extreme conditions. Botulinum toxin is the most powerful neurotoxin known.
• Disease results from absorption of toxin into the circulation from a mucosal surface or wound. Botulinum toxin does not penetrate intact skin.
• In foodborne variety, disease is caused by ingestion of preformed toxin. Although rapidly inactivated by heat, the toxin can survive the proteolytic environment of the stomach.
• In wound botulism, toxin is elaborated by organisms that contaminate a wound. Most cases reported are from California.
• In infant botulism, toxin is produced by organisms in the GI tract.
• Inhalational botulism has been demonstrated experimentally in primates. This manufactured form results from aerosolized toxin, and has been attempted by bioterrorists.
• Myasthenia gravis
• Guillain-Barré syndrome
• Tick paralysis
Search made for toxin and the organism (see “Laboratory Tests”)
• Electrophysiologic studies (EMG) may aid in the diagnosis.
• Samples of food and stool are cultured for the organism.
• Food, serum, and stool are sent for toxin assay.
• Supportive care with intubation if respiratory failure occurs
• Debridement of the wound in wound botulism
ACUTE GENERAL Rx
• Give trivalent equine botulinum antitoxin as early as possible. Once a clinical diagnosis is made, antitoxin should be administered before laboratory confirmation.
1. Give one vial by IM injection and one vial IV.
2. The antitoxin is available from the Centers for Disease Control and Prevention; it is derived from horse serum, so there is a significant incidence of serum sickness.
3. Skin testing, and possible desensitization, is recommended before treatment.
• Give wound botulism patients penicillin, 2 million U IV q4h.
• Rehabilitation/physical therapy
• Highest mortality in the first case in an outbreak, with subsequent cases receiving rapid treatment
• Complete recovery for most individuals
Intestinal Botulism In intestinal botulism, toxin is produced in and absorbed from the intestine after the germination of ingested spores. Intestinal botulism in infants (infant botulism) is the most common form of botulism. The severity ranges from mild illness with failure to thrive to fulminant severe paralysis with respiratory failure. Infant botulism may be one cause of sudden infant death. The identification of contaminated honey as one source of spores has led to the recommendation that honey not be fed to children < 12 months of age. Most cases, however, cannot be attributed to a particular food source. The factors permitting intestinal colonization with C. botulinum are not fully defined, but cases usually involve infants < 6 months of age; susceptibility may decrease as the normal intestinal flora develops. Intestinal botulism involving adults is uncommon. The patient may have a history of gastrointestinal disease, gastrointestinal surgery, or recent antibiotic therapy. Toxin and organisms may be identified in the stool.
EPIDEMIOLOGY & DEMOGRAPHICS
INCIDENCE (IN U.S.): Approximately 24 cases/year of foodborne illness, 3 cases/year of wound botulism, and 71 cases/year of infant botulism