Tetanus Prophylaxis

Tetanus: Pathophysiology - Spore Wars

• Agent: Clostridium tetani (anaerobic); spores in soil, dust, feces.
• Toxin: Tetanospasmin (neurotoxin).
• Pathogenesis:
  • Spores enter wound → germinate.
  • Toxin via retrograde axonal transport to CNS.
  • Inhibits glycine & GABA release (Renshaw cells) → disinhibition.
• Manifestations: Incubation 3-21 days.
  • Trismus (lockjaw), risus sardonicus, opisthotonus.
  • Autonomic dysfunction.

⭐ Tetanospasmin, the neurotoxin from Clostridium tetani, acts by blocking the release of inhibitory neurotransmitters (GABA and glycine) in the central nervous system, leading to unopposed muscle contraction and spasm.

Tetanus: Wound Risk - Danger Zones

Understanding wound type is crucial for appropriate tetanus prophylaxis.

⭐ Wounds older than 6 hours, or those with devitalized tissue, contaminants (soil, feces, saliva), puncture type, crush injury, burns, or frostbite are considered tetanus-prone.

Tetanus: Immunization - Shot Sleuthing

• Primary Immunization:
  • Childhood: 3 doses (DTP/DT/TT).
  • Adults: 3 doses (Td/Tdap).
• Booster Doses:
  • Every 10 years.
  • Every 5 years for tetanus-prone wound if last dose >5 years ago.
• History: Documented vs. unreliable. Serological testing not routine.

⭐ A patient is adequately immunized if they have documented completion of a primary series of at least 3 doses of tetanus toxoid-containing vaccine, with the last dose within 10 years (or 5 years for a tetanus-prone wound).

Tetanus: Prophylaxis Protocol - Guard Up!

Key Agents for Prophylaxis:

• Active Immunity: Tetanus Toxoid (TT/Td/Tdap) 0.5 mL IM.
• Passive Immunity: Tetanus Immunoglobulin (TIG).
  • Human (hTIG): 250 IU IM.
  • Equine: 1500-3000 IU IM (after sensitivity test).
• 📌 Administer TT & TIG at separate sites if both indicated.

Categorize wound: Clean/Minor vs. Tetanus-Prone (e.g., contaminated with dirt/faeces/saliva, devitalized tissue, >6h old, puncture, avulsion, crush, burn, frostbite).

⭐ For a tetanus-prone wound in a patient with unknown or incomplete (<3 doses) vaccination history, both Tetanus Toxoid (e.g., Td 0.5 mL IM) and Tetanus Immunoglobulin (TIG 250 IU IM for human) should be administered at separate sites.

Tetanus: Special Cases - Handle with Care

• Pregnancy: Tdap preferred, ideally 27-36 weeks (2nd/3rd trimester); Td if Tdap unavailable.

  ⭐ Tdap in each pregnancy (27-36 weeks) gives neonatal passive immunity (tetanus, diphtheria, pertussis).

• HIV/Immunocompromised: Full primary series + boosters. TIG per guidelines; response may be suboptimal.
• Incomplete/Unknown History: Treat as unimmunized (<3 doses).
• Elderly: Standard guidelines; consider immunosenescence.
• Prior Vaccine Reaction: Assess severity; specialist consultation if severe_

High‑Yield Points - ⚡ Biggest Takeaways

• Clean minor wounds: If <3 doses or unknown history, give Td. If ≥3 doses, Td only if >10 years since last dose.
• All other wounds (dirty/major): If <3 doses or unknown, give Td + TIG. If ≥3 doses, Td if >5 years since last dose.
• TIG (Tetanus Immunoglobulin): Standard prophylactic dose is 250 IU IM.
• Full primary immunization: Requires three properly spaced doses of tetanus toxoid.
• Booster doses: Every 10 years routinely; or after 5 years for tetanus-prone wounds in immunized individuals.