Makindo Medical Notes

🤒 Botulism is a rare but potentially fatal neuroparalytic illness caused by toxins from Clostridium botulinum. It typically presents with a symmetrical descending flaccid paralysis starting with the eyes and bulbar muscles, progressing to respiratory failure. ⚠️ Pupils are often fixed and dilated due to impaired acetylcholine release at the neuromuscular junction.

🧾 About

• Severe foodborne neurotoxin-mediated illness 🥫
• Medical emergency due to risk of respiratory compromise
• Toxin blocks presynaptic acetylcholine release at the motor endplate

🔬 Characteristics

• Large Gram-positive anaerobic spore-forming rods
• Subterminal oval spores
• Types A–F produce exotoxins, with A, B, E most relevant in humans
• Neurotoxin → irreversible blockade of ACh release → flaccid paralysis

🌍 Sources

• Soil, dust, animal faeces
• Poorly preserved foods (e.g., home-canned vegetables, fermented fish)
• Infants 🍼: honey (C. botulinum spores germinate in immature gut)
• Wound botulism: IV drug use (esp. black tar heroin)
• Heating >85°C for ≥5 minutes destroys toxin

⚠️ Clinical Features

• Early: Diplopia, ptosis, blurred vision, dry mouth, dysphagia, dysarthria
• Progression: Descending symmetrical weakness → neck → arms → respiratory muscles → legs
• No sensory loss (pure motor syndrome)
• Infants: constipation, weak cry, poor suck, hypotonia (“floppy baby”)

🧪 Investigations

• Gram stain: Gram +ve bacilli
• Anaerobic culture from stool, wound, or food
• Toxin detection (stool, serum, suspected food) – reference lab required
• Electromyography (EMG): shows incremental response with rapid repetitive stimulation

💊 Management

• 🚑 Airway & respiratory support – mechanical ventilation often required
• 💉 Botulinum antitoxin (equine-derived or human immunoglobulin in infants) – give early, before toxin binds
• 💊 Antibiotics: Penicillin or Metronidazole for wound botulism (❌ not used in foodborne disease as lysis may release more toxin)
• ❌ Avoid aminoglycosides – worsen neuromuscular blockade
• 👶 Infant botulism: human-derived botulism immune globulin (BIG-IV) preferred

📊 Prognosis

• Mortality 5–10% with modern intensive care
• Recovery takes weeks–months as new nerve terminals sprout
• Relapse is rare but prolonged ventilation may be needed

📚 References

• UKHSA Botulism Guidance
• CDC Botulism Clinical Guidelines (2023)