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 features
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