Tetanus - Wound Types (Park's Textbook of Preventive and Social Medicine)

Types of Tetanus (by Source / Portal of Entry)

(a) Traumatic Tetanus

• Most important and common type
• Trauma is the major cause of tetanus
• Can result from trivial or even unnoticed wounds - no wound is too minor to be dismissed

(b) Puerperal Tetanus

• Follows abortion more frequently than normal labour
• A post-abortal uterus is a favourable site for germination of tetanus spores
• Females are at special risk during delivery or abortion

(c) Otogenic Tetanus

• The ear is a rare portal of entry
• Foreign bodies such as infected pencils, matches, and beads may introduce infection
• Primarily a paediatric problem, but cases may occur in adults

(d) Idiopathic Tetanus

• No definite history of injury
• Three proposed explanations:
  1. Result of microscopic trauma
  2. Absorption of tetanus toxin from the intestinal tract
  3. Inhalation of tetanus spores initiating infection

(e) Tetanus Neonatorum (Neonatal Tetanus)

• Kills about 85% of those afflicted in many countries
• Common cause: infection of the umbilical stump after birth
• First symptom typically appears around the 7th day - hence known as "8th day disease" in Punjab
• Common where hygiene is poor and deliveries occur in non-aseptic conditions (umbilical cord cut with unclean instruments, or stump dressed with ashes, soil, or cowdung)

Wound Classification for Post-Injury Tetanus Prophylaxis

Category 1: Clean Minor Wounds

• Less than 6 hours old
• Clean
• Non-penetrating
• Negligible tissue damage

Category 2: "Other Wounds" (Tetanus-Prone)

• More than 6 hours old, OR
• Contaminated (soil, dust, feces), OR
• Penetrating wounds, OR
• With significant tissue damage/necrosis

Post-Injury Prophylaxis Scheme (Park's Table)

Key principle from Park's: "All wounds must be thoroughly cleaned soon after injury - removal of foreign bodies, soil, dust, necrotic tissue. This procedure will abolish anaerobic conditions which favour germination of tetanus spores."

Additional Notes from Park's

• Incubation period: Usually 3-21 days; shorter incubation = worse prognosis
• Tetanus is not transmitted person to person (period of communicability: none)
• High-risk groups: Agricultural workers (soil contact), males aged 5-40 years, rural populations
• ATS precaution: When antitoxin serum (ATS) is used, adrenaline (1:1000, 0.5-1 ml IM) and hydrocortisone 100 mg IV must be kept ready for anaphylactoid reactions; a subcutaneous test dose of 0.1 ml ATS should be given and patient observed for at least 30 minutes