Tetanus Infection: Understanding Symptoms, Progression, and Treatment

Tetanus is caused by Clostridium tetani neurotoxin (tetanospasmin). Spores enter through wounds → germinate in anaerobic conditions → toxin travels via retrograde axonal transport to CNS.

Pathophysiology

Tetanospasmin cleaves synaptobrevin (VAMP) → blocks inhibitory neurotransmitter (GABA, glycine) release from spinal/brainstem interneurons → unopposed motor neuron firing → rigid spasms.

Clinical Stages

1. Incubation: 3–21 days (avg 10). Shorter = worse prognosis.
2. Prodrome: Local stiffness, irritability, headache.
3. Generalized Tetanus (80%): Trismus (lockjaw) → risus sardonicus → opisthotonus (arching) → generalized tonic spasms triggered by stimuli (light, sound, touch). Autonomic instability (labile BP, tachycardia, sweating).
4. Localized/Cephalic: Milder, near entry site or cranial nerves.

Complications

• Laryngospasm, aspiration pneumonia, pulmonary embolism, fractures (spasms), rhabdomyolysis, cardiac arrest.
• Mortality: 10–20% with ICU care; higher without.

Treatment

• Human Tetanus Immune Globulin (HTIG): 3000–6000 IU IM — neutralizes unbound toxin.
• Antibiotics: Metronidazole (preferred) or penicillin — kills organisms, stops toxin production.
• Wound Care: Debridement, excision.
• Supportive: ICU, sedation (midazolam, propofol), paralysis (vecuronium) + ventilation for severe spasms, autonomic management (labetalol, morphine), nutrition.

Prevention

Vaccination: DTaP (children), Tdap (adolescents/adults), Td/Tdap boosters every 10 years. Post-exposure: Tdap + HTIG if wound dirty/uncertain history.

Tetanus is preventable. Vaccinate.