BOTULISM

BOTULISM - John C. Bradford, DO
BASICS
DESCRIPTION
• An intoxication-producing paralytic disease caused by neurotoxins of Clostridium botulinum, the most toxic substances known to science
• The toxin prevents acetylcholine release at presynaptic membranes, blocking neuromuscular transmission in cholinergic nerve fibers.
• 5 forms exist
- Food-borne botulism
- Infantile botulism
- Wound botulism
- Hidden or intestinal botulism
- Inadvertant botulism
- Inhalation (potential sixth form through deliberate release of toxin)
• System(s) Affected: Endocrine/Metabolic; Gastrointestinal (GI); Nervous
• Synonym(s): Sausage poisoning; Kerner disease
ALERT
Pediatric Considerations
Avoid honey in the 1st year of life.
GENERAL PREVENTION
• Avoid giving honey to infants.
• Do not eat or taste food from bulging cans, or if food smells "off."
EPIDEMIOLOGY
• Predominant age
- Food-borne: All ages
- Infantile: 2-4 months (rare after 6 months)
- Wound: Usually younger adult
- Inadvertent: >1 year
• Predominant sex
- Food-borne and infantile: Male = Female
- Wound: Male > Female
- Inadvertent: Female > Male
Incidence
• Average of 110 cases per year (25% food-borne, 72% infant)
• Wound botulism incidence increasing due to IV heroin use and cocaine abuse
• Hidden or intestinal: More common in disorders of the GI tract, such as prior surgery, Crohn disease, or recent antibiotic use
• Inhalation: Only a single incident involving 3 laboratory workers has been described.
RISK FACTORS
• Food-borne: Ingestion of home-canned or prepared foods
• Infantile: From ingestion of honey; breastfeeding (controversial)
• Wound: IV drug use (e.g., black tar heroin) or "skin popping." Sinusitis secondary to cocaine use also reported.
ETIOLOGY
• Ingestion of C. botulinum neurotoxins (A, B, and E most common)
• Food-borne, usually from home-canned vegetables, prepared foods, or foods incubated in anaerobic conditions
• Infantile from ingestion of spores in environment or occasionally in honey
• Wound due to contamination with toxin-producing C. botulinum
• Hidden or intestinal (source yet identified)
• InadvertentIM injections of botulinum toxin

DIAGNOSIS
SIGNS AND SYMPTOMS
• Food-borne
- Onset 2-36 hours after ingestion, as long as 14 days
- Nonspecific findings early (nausea, vomiting, malaise, dizziness, and abdominal distension)
- Dry mouth
- Constipation, urinary retention
- Symmetric descending weakness or paralysis of motor and autonomic nerves, usually beginning with the cranial nerves
- Cranial nerve paralysis (ptosis; extraocular muscle paresis; fixed, dilated pupils; dysphagia)
- Postural hypotension
- Muscle weakness, respiratory paralysis (no sensory deficits)
- Afebrile
- Progression over several days
• Infantile
- Constipation (early sign)
- Loss of head control
- Loss of suck
- Loss of facial expression and verbalization
- Symmetric descending weakness and cranial nerve paresis similar to food-borne form
- Diminished or absent deep tendon reflexes
- Autonomic dysfunction
- Afebrile
- Usual progression over 2-5 days; can be short as a few hours
• Wound
- Onset 4-14 days postinjury
- Findings similar to food-borne botulism, but GI symptoms less common
- May be febrile
• Hidden
- Possible adult variant of infant botulism
- Findings similar to infant botulism
- Inadvertent
- Moderate to marked clinical weakness following IM therapeutic injections
- Autonomic nervous system deficits also reported
- Inhalation
- Likely as irritant upper airway prodrome followed by variable degrees of paralysis
TESTS
• Stool contains organism and toxin
• Serum toxin present in food-borne form
Lab
• Routine testscheck for hypokalemia
• CSF testingnormal helps differentiate from Guillain-Barre syndrome
• Toxin detected in gastric contents, blood, feces, and suspected food and containers
• Confirmation available at Centers for Disease Control and prevention (CDC) and some state laboratories
• Pulmonary function testing
• Disorders that may alter lab results
- Underlying myoneural disease
Diagnostic Procedures/Surgery
Electrophysiology testing can provide presumptive evidence of botulism in patients with the clinical picture and in whom bioassay studies are negative. The most consistent finding is a smaller amplitude evoked muscle action potential on repetitive nerve stimulation with incremental response.
Pathological Findings
Nonspecific
DIFFERENTIAL DIAGNOSIS
• Guillain-Barre syndrome
• Encephalitis
• Tick paralysis
• Myasthenia gravis
• Eaton Lambert myasthenic syndrome
• Basilar artery stroke
• Congenital neuropathy or myopathy
• Sepsis
• Hypokalemic periodic paralysis
• Polio
• Other poisonings (organophosphate, shellfish, Amanita mushrooms, atropine, and aminoglycosides)
• Miller Fisher variant of Guillian-Barre syndrome
• Diphtheritic neuropathy
TREATMENT
Advanced medical and nursing supportive care with special attention to respiratory status; aggressive airway management for those at risk for respiratory failure
GENERAL MEASURES
• Meticulous airway management
• Monitor pulmonary function
• Physical therapy with range of motion exercise and assisted ambulation as tolerated
• Prevention of decubiti
Diet
Nasogastric feedings, if needed
Activity
Bed rest initially
MEDICATION (DRUGS)
First Line
• Antitoxin therapy with trivalent A-B-E antitoxinCall CDC Assistance, (770) 488-7100 for help in locating and acquiring the antitoxin. A single vial IV provides adequate serum levels.
• Most benefit from antitoxin in cases with rapidly progressive paralysis.
• Early administration important
• Horse serum derived: Up to 20% reaction incidence. Consider skin testing or pretreatment with steroids or antihistamines.
• Infantile
- Treatment with Human Botulism Immune Globulin recommended by some authors
- Available only through the California State Health Department (510) 540-2646
• Wound
- Antitoxin therapy with trivalent A-B-E antitoxin, one vial IV and one vial IM, repeat in 2-4 hours if persistent symptoms
- Antibiotics unproven by clinical trial but widely used and recommended
 Penicillin G (3 million units IV q4h in adults)
 Metronidazole (500 mg IV q8h) for penicillin-allergic patients
- Vaccinepentavalent vaccine available
 Efficiency in terrorist attack is unknown
 Newer vaccines being developed
• Contradictions: Previous reaction to horse serum-containing medications represents a relative contraindication to trivalent antitoxin. Human Botulism Immune Globulin has a greatly decreased risk of hypersensitivity reactions.
SURGERY
Wound excision debridement
FOLLOW-UP
PROGNOSIS
• Delay in administering toxin is the most important factor that affects clinical course and outcome
• Mortality: 10-40%
• Mortality for patients >60 years twice that of younger patients
• Full recovery may take months.
COMPLICATIONS
• Aspiration pneumonia
• Nosocomial infection
• Hypoxic tissue damage
• Death
PATIENT MONITORING
Cardiorespiratory monitoring during illness
REFERENCES
1. Horowitz BZ. Botulinum toxin. Crit Care Clin. 2005;21:825-839.
2. Cherington M. Botulinum: Update and review. Semin Neurol. 2004;24(2):155-163.
3. Arnon SS. Botulinum toxin as a biological weapon. JAMA. 2001;285(8):1059-1070.
4. Coffield JA. Botulinum neurotoxin: The neuromuscular junction revisited. Crit Rev Neurobiol. 2003;15(3-4):175-196.
MISCELLANEOUS
• Other notes
- Organism present in stools of 1-2% of healthy individuals
- Release of toxins in the gut may worsen symptoms of infantile botulism by bacterial lysis.
• See also: Food Poisoning; Bacterial