Botulism

Clostridium botulinum is a common environmental organism that produces spores; in botulism (food poisoning), the toxin is ingested and causes profound neuromuscular blockade, leading to autonomic and motor paralysis

Aetiology

  • Clostrudium botulinum - common environmental organism that produces spores, present in soil
    • Contaminated food
    • Contamination of wounds
    • Injection of contaminated street heroin

Pathophysiology

  • Extremely potent exotoxin that acts at motor neurone terminals to irreversibly inhibit ACh release
  • Enters presynaptic terminals to enzymatically modify proteins involved in the docking of vesicles containing ACh to the presynaptic membrane, which prevents exocytosis
  • Low dose botulinum haemaglutin complex can be administered IM to treat overactive muscles (dystonias) and also 'botox' for wrinkles

Clinical presentation

  • Rapid onset (over hours) motor weakness, without sensory loss
  • Typically ascending paralysis

Investigations

  • Detection of toxin in serum, urine, stool, vomit/gastric fluid

Management

  • Supportive - treat respiratory failure, will eventually improve
  • Anti-cholinesterases are ineffective as therapy
  • Antitoxin is available in some countries but the risk of anaphylaxis is relatively high so should be used only in severe cases
  • High death rate, recovery takes weeks