All confirmed and suspected cases must be reported immediately to the Health Unit.
Tetanus (lockjaw) is caused by a neurotoxin produced by the bacterium Clostridium tetani (C. tetani). Between 2013 and 2017, an average of two cases occurred per year in Ontario.
Tetanus is an acute disease that can manifest in four clinical forms based on presentation: local, cephalic, neonatal and generalized tetanus.
Local tetanus is an uncommon condition in which persistent muscle contraction is limited to the area of injury but can most often progress to generalized tetanus. Cephalic tetanus is rare and involves the cranial nerves or can occur with otitis media. Neonatal tetanus is a form of generalized tetanus in newborn infants who do not have passive protection from maternal antibodies.
Generalized tetanus is the most common manifestation of the disease occurring in approximately 80% of reported cases. Generalized tetanus is characterized by painful muscle spasms, usually in a descending pattern beginning in the masseter muscle (trismusor lockjaw), followed by stiff abdominal muscles. Abdominal rigidity is a common first presentation of disease in older children and adults. Duration of spasms is generally three to four weeks, though recovery may take months.
With disease progression, generalized prolonged frequent spasms may occur, contributing to serious complications and death unless treatment is provided. Case-fatality ratios vary from 10% to over 80% in unvaccinated individuals; highest rates are found in infants and the elderly.
Modes of Transmission
Spores are introduced into the body through a break in the skin (e.g. puncture wound, animal bites, burns) or contaminated injectable street drugs, that have been contaminated with soil, street dust, or animal or human feces.
Usually 3–21 days (average eight days), with a range from one day to several months, depending on the character, extent and location of the wound; most cases occur within 14 days of exposure. In general, shorter incubation periods are associated with more heavily contaminated wounds, more severe disease and a worse prognosis. Incubation period for neonatal tetanus ranges from four to 14 days (average seven days) after birth.
Period of Communicability
No direct person to person transmission.
Susceptibility is general in unimmunized or inadequately immunized persons; active immunity is induced by the tetanus toxoid and persists for at least ten years after completion of the immunization series. Due to waning immunity, booster doses with a tetanus toxoid-containing vaccine are required every ten years after the 4–6 year old booster immunization to maintain high levels of immunity. Recovery from tetanus does not result in immunity or prevent recurrence, therefore active immunization is indicated after recovery.
Diagnosis and Laboratory Testing
Clinical evidence of illness without other apparent medical cause with or without isolation of Clostridium tetani (C. tetani) and with or without history of injury.
There is no diagnostic laboratory test for tetanus. Diagnosis is determined by clinical findings.
Note: Reactive Anti-Tetanus Toxoid Immunoglobulin G (IgG) by the enzyme immunoassay (EIA) method does not provide proof of protection against tetanus.
Consult with the Public Health laboratory about appropriate specimens and testing methodology.
Treatment and Case Management
The primary goal in managing cases is to remove the source of toxin production and neutralizing toxin that may have been released by:
- Timely, thorough cleaning of wound including removal of necrotic tissue and foreign materials; and
- Ensuring high circulating concentrations of tetanus antibody which inactivate the toxin.
Treatment should be administered as per the attending health care provider. For further guidance, including post-exposure prophylaxis and wound management, please refer to the current Canadian Immunization Guide. Tetanus disease does not confer immunity since illness can be caused by a very small amount of toxin. The case should begin or continue with tetanus toxoid-containing vaccinations after recovery.