Description

• Severe neurological disorder caused by the bacteria Clostridium tetani. The clinical presentation varies and can include intermittent tonic spasms of voluntary muscles, autonomic instability, and hypertonia. Tetanus usually presents as:
  • Generalized (most common, most severe)
  • Localized (generally mild)
  • Cephalic (affects cranial nerves)
  • Neonatal (very high mortality, rare in the US)
• Incubation period: Usually 1 day to several months
• Usual course is 3–6 weeks duration.
• Can be fatal
• Severity is determined by frequency of spasms, presence of opisthotonusm and autonomic dysfunction (1)[A].

• Mortality high in young.
• Infection usually enters through umbilical cord via improperly cleaned instruments.
• Can affect newborns born to improperly vaccinated mothers. Transplacental transfer of antitoxin can be protective (to the newborn) for first 1–2 months of life (2).

• Must treat vigorously
• Infection may enter uterus postpartum.
• Tetanus toxoid in pregnancy (if indicated/higher risk) can reduce neonatal tetanus deaths (3)[A].

Epidemiology

• Rare in the US due to vaccination:
  • 0.10/1 million annually in the US
  • Near elimination of neonatal tetanus due to vaccination and improved childbirth practices
• Estimated 700,000–1,000,000 cases annually worldwide.

• Age: Median 49 years
• Gender: Male > Female

Risk Factors

• Lack of vaccination or up-to-date booster
• Presence or history of a wound and/or devitalized tissue is 1 of the most important risk factors.
• Chronic wounds, wounds predisposed to anaerobic conditions, contaminated wounds, puncture wounds, crush wounds, surgical wounds, burns and wounds containing foreign bodies
• Wounds exposed to soil, feces, or saliva
• Unsterile intramuscular or subcutaneous injections
• Compound fractures
• Diabetes
• Recent history of a septic abortion
• Age: >65 years and newborns (umbilical entry, circumcision)
• Early postpartum with an infected uterus

General Prevention

• Active immunization for adults ≥19 (4):
  • Unvaccinated: 3 doses of Td (tetanus and diphtheria toxoid) containing vaccine. First 2 doses at least 4 weeks apart. 3rd dose 6–12 months after the 2nd. Tdap should be used as the 1st dose (5).
  • Incompletely vaccinated (<3 doses of the primary vaccine series): Administer remaining doses (5).
  • Completed primary vaccination series but lacking updated booster vaccination: A 1-time dose of Tdap (Tetanus, diphtheria, acellular pertussis), followed by Td booster every 10 years (5).
• Active immunization for children:
  • 2 months–6 years of age: Primary series with DTaP (diphtheria, tetanus toxoid and acellular pertussis) at 2, 4, 6, and 15–18 months of age, followed by a booster at 4–6 years (6).
  • 7–18 years of age in those who have received the primary vaccination series: Tdap booster at 11 years (6).
• Postexposure prophylaxis (as a part of wound and/or traumatic injury management):
  • All patients with wounds and/or devitalized tissue should be evaluated for tetanus prophylaxis.
  • In the setting of unknown vaccination history, consider patient unvaccinated.
  • In addition to tetanus immunization, human tetanus immune globulin (passive immunization) should be administered where indicated.
  • Age- and situation-appropriate preparations should be used. Special populations to consider include pregnant patients, health care workers, patients >65, pediatric patients, and those in contact with infants <12 months of age.
• Clean and minor wounds:
  • Patients with <3 doses of primary vaccination or unknown vaccination status: Administer tetanus toxoid containing vaccine. The vaccination series should then be continued to completion.
  • Patients with >3 doses of primary vaccination: Administer tetanus toxoid containing vaccine only if last dose >10 years ago.
• Wounds more severe than a clean and minor wound (particularly those under “risk factors”):
  • Patients with <3 doses of primary vaccination or unknown vaccination status: Administer tetanus toxoid containing vaccine and human tetanus immune globulin. Vaccination series should then be continued to completion. Use separate syringes and separate injection sites for tetanus toxoid and tetanus immune globulin.
  • Patients with >3 doses of primary vaccination: Administer tetanus toxoid containing vaccine if last dose was ≥5 years ago.
• Wound débridement/decontamination.

Pathophysiology

• C. tetani is a gram-positive obligate anaerobic rod. The organism is sensitive to heat and oxygen, but its spores are heat-resistant.
• Usually enters the body through a contaminated wound or devitalized tissue
• Following entry, C. tetani produces the toxins tetanospasmin and tetanolysin:
  • Tetanospasmin causes the neurologic and autonomic symptoms of tetanus.
  • Tetanolysin causes hemolysis, but its other clinical effects are unclear.
• Tetanospasmin enters the CNS peripherally, then travels centrally to the brain and spinal cord.
• Tetanospasmin blocks select inhibitory neurons, resulting in unopposed muscle tone, muscle contraction, spasms, seizures, and autonomic instability.
• Toxin effects are long lasting, therefore the clinical course usually lasts several weeks.

Commonly Associated Conditions

See “Risk Factors.”