Botulism

Description

• A paralytic illness caused by a neurotoxin produced by the anaerobic bacterium Clostridium botulinum
• Characterized by acute onset of cranial nerve dysfunction (diplopia, difficulty swallowing or speaking), symmetric descending weakness, and flaccid paralysis
• Eight antigenic types of C. botulinum (A to H). Types A, B, E, and, in rare cases, F, cause disease in humans.
• Forms include (1):
  • Foodborne: ingestion of preformed toxin
  • Infant botulism: caused by ingestion of C. botulinum that produces toxin in the GI tract
  • Wound: caused by wound infection with C. botulinum and subsequent toxin secretion
  • Aerosolized/inhalational botulism: bioterrorist weapon with high toxicity; <1 μg is lethal human dose; not known to occur naturally
  • Adult intestinal toxemia: similar to infant botulism; rare in adults
  • Iatrogenic: injection of toxin for cosmetic or therapeutic (spastic neuromuscular disorders, glandular hypersecretion, pain) effect
• System(s) affected: neuromuscular, respiratory, GI
• Synonym(s): sausage poisoning; Kerner disease

Epidemiology

Incidence

• 205 confirmed cases in the United States in 2016, with three deaths: two foodborne, one unknown (2)
• 73% of cases were infant botulism, 14% were foodborne, 12% were wound related, and 1% were due to unknown etiologies (2).
• No person-to-person transmission documented (2)

Prevalence

• Predominant age (2)
  • Foodborne: median 39 years; range 23 to 89 years
  • Infantile: median 4 months, range 0 to 10 months
  • Wound: median 45 years, range 25 to 68 years, 93% injection drug users
• Predominant gender (2)
  • Infantile: male = female
  • Foodborne: male > female
  • Wound: male > female

Etiology and Pathophysiology

• C. botulinum is an anaerobic gram-positive, spore-forming, rod-shaped bacillus.
• Eight distinct toxin types: A, B, C, D, E, F, G, and H
• A, B, E, and F cause disease in humans.
• Disease results from ingestion of Clostridium, followed by local toxin production in GI tract (e.g., from home-canned vegetables).
• Infantile botulism due to ingestion of spores in environment or foods (e.g., honey)
• Wound contamination with toxin-producing C. botulinum can produce clinical disease with hematogenous spread of toxin.
• The toxin inhibits acetylcholine release at presynaptic membranes, blocking neuromuscular transmission and causing paralysis.

Risk Factors

• Foodborne: ingestion of home-canned or prepared foods that are contaminated
• Infantile: ingestion of environmental spores; ingestion of honey (minor but preventable source)
• Immunocompromised state
• Wound: IV drug use (black tar heroin), “skin popping,” snorting cocaine

General Prevention

• Foodborne: proper handling, processing, preparation (heating), and storage of food; avoid eating from bulging cans or unprepared/underprepared food (1).
• Infant: caretaker hand washing. Avoid honey in infants <1 year of age (1).
• Wound: proper wound care; abstain from injection drug use or snorting cocaine (1).
• Health care providers: universal precautions (1)
• If meningitis is suspected in patients with flaccid paralysis, use droplet precautions (1).
• Raking soil and algae to introduce oxygen prevents spore development.
• Heat food or drink to internal temperature of 85°C for at least 5 minutes (1).
• After exposure to C. botulinum toxin, clean clothing and skin with soap and water (1).
• Clean contaminated objects or surfaces with 0.1% bleach solution. Promptly discard all potentially contaminated food (1).
• Vaccination has been discontinued (1).