Is antitetanus serum (ATS) indicated for a 2-week old untreated wound?

Tetanus Prophylaxis for a 2-Week Untreated Wound

Yes, tetanus prophylaxis is still indicated for a 2-week untreated wound, as the timing of prophylaxis depends on the patient's vaccination history and wound characteristics, not the age of the wound itself. The critical window for tetanus prevention extends well beyond 2 weeks, as the incubation period for tetanus typically ranges from 3-21 days but can be longer 1, 2.

Wound Assessment and Classification

The first priority is proper wound care regardless of timing:

• Thoroughly clean and debride the wound to remove debris that might harbor Clostridium tetani spores, as this is a critical first step in tetanus prevention 2
• Perform surgical debridement of any necrotic tissue, as wounds creating anaerobic conditions are favorable for C. tetani growth 2
• Classify the wound as either clean/minor or tetanus-prone (contaminated with dirt, feces, soil, saliva, puncture wounds, avulsions, crush injuries, burns) 1, 3

Vaccination History Assessment Algorithm

Assume no prior vaccination if the history is unknown or uncertain 4, 2. Follow this decision tree:

For Clean, Minor Wounds:

• ≥3 prior doses, last dose <10 years ago: No tetanus toxoid or TIG needed 1, 3
• ≥3 prior doses, last dose ≥10 years ago: Give tetanus toxoid-containing vaccine (Tdap preferred if not previously received), NO TIG 1, 3
• <3 doses or unknown history: Give tetanus toxoid-containing vaccine AND complete primary series, NO TIG 1

For Tetanus-Prone/Contaminated Wounds:

• ≥3 prior doses, last dose <5 years ago: No tetanus toxoid or TIG needed 1, 3
• ≥3 prior doses, last dose ≥5 years ago: Give tetanus toxoid-containing vaccine (Tdap preferred), NO TIG 1, 3
• <3 doses or unknown history: Give BOTH tetanus toxoid-containing vaccine AND TIG 250 units IM 1, 3

Administration Details

When both tetanus toxoid and TIG are required:

• Administer at separate anatomical sites using separate syringes 4, 1
• Use adsorbed toxoid when giving concurrent TIG 4
• The standard TIG prophylactic dose is 250 units intramuscularly for both adults and children 1

Special Populations Requiring TIG Regardless of History

• Persons with HIV infection or severe immunodeficiency should receive TIG for any contaminated wound regardless of vaccination history 1, 3
• In mass-casualty settings with limited TIG supply, prioritize persons aged >60 years and immigrants from regions other than North America or Europe 1, 2

Vaccine Selection

• For adults ≥7 years: Use Td or Tdap; strongly prefer Tdap if not previously received to provide pertussis protection 4, 3, 2
• For pregnant women: Use Tdap regardless of prior Tdap history if tetanus toxoid is indicated 3
• For children <7 years: Use DTP (or DT if pertussis contraindicated) 4, 2

Critical Clinical Pearls

• Complete primary vaccination provides long-lasting protection >10 years for most recipients 4
• Rarely has tetanus occurred among persons with documentation of a complete primary series 4
• The case fatality rate remains high (18-21%) even with modern medical care 2
• A documented case occurred in a 79-year-old woman with proper vaccination whose last booster was 7 years prior to a high-risk injury; she developed generalized tetanus because TTV was not administered during initial wound care 5
• More frequent doses than recommended may cause increased adverse reactions, including Arthus-type hypersensitivity 3

Contraindications

• Patients with history of Arthus reaction following previous tetanus toxoid should not receive tetanus toxoid-containing vaccine until >10 years after the most recent dose, regardless of wound condition 1, 3

Follow-Up

Ensure completion of the primary vaccination series for inadequately vaccinated patients at discharge or follow-up visits 4, 2.