- Reason for surveillance
- Case definition
- Notification criteria and procedure
- The disease
- Managing single notifications
1. Reason for surveillance
To identify failures in immunisation and so inform better prevention strategies.
2. Case definition
A confirmed case requires
- Laboratory definitive evidence
- or clinical evidence.
Laboratory definitive evidence
Isolation of Clostridium tetani from a wound in a compatible clinical setting and prevention of positive tetanospasm in mouse test from such an isolate using specific tetanus antitoxin.
A clinically compatible illness without other apparent cause.
3. Notification criteria and procedure
Tetanus is to be notified by:
- hospital CEOs on clinical diagnosis (ideal reporting by telephone or routine mail)
- school principals and directors of child care facilities (ideal reporting by telephone on same day of notification).
Only confirmed cases should be entered onto NCIMS.
4. The disease
Neurotoxin produced by the anaerobic, spore-forming bacillus Clostridium tetani.
Mode of transmission
Tetanus spores are present in the environment and enter the tissues through breaks in the skin. Spores are resistant to drying, heat and antiseptics and may remain viable in the environment for years.
Tetanus spores are widely distributed in soil and in animal faeces. Manure enriched soil may contain large numbers of spores. Spores can also be found on skin surfaces and in contaminated heroin.
Anaerobic conditions such as deep puncture wounds allow the spores to germinate into vegetative bacilli that produce a neurotoxin "tetanospasmin".
The neurotoxin binds to skeletal muscle and neuronal cells and blocks inhibitory impulses to these cells and this causes involuntary muscle contraction.
Tetanus is not directly transmitted from person-to-person.
The typical incubation period is around 10 days with a range of 3 to 21 days.
Generalised tetanus usually starts gradually over several days. The patient may initially develop "risus sardonicus" (a tightening of facial muscles that causes a characteristic smile-like facies) and "lockjaw" or "trismus" (masseter spasm that prevents mouth opening normally).
Gradually the muscle spasms increase with hyper-extension of the neck, back and lower limbs and flexion of the upper limbs ("opisthotonus"). Muscle spasms are extremely painful and can be precipitated by external stimuli. There may be associated abdominal rigidity. There is often autonomic dysfunction with increased sweating, hypertension and tachycardia. Severe spasm persist for 1 week or more and subside over several weeks.
The case-fatality rate varies from 10 to over 80 per cent, and is highest in infants and the elderly. Prognosis is poorer if there is rapid progression to generalised seizures from onset.
Neonatal tetanus is occasionally seen in infants born to mothers who have never been immunised against tetanus. The umbilical stump can be infected through poor obstetric or post natal care. In India and Pakistan, neonatal tetanus sometimes occurs when the umbilical stump is covered in ghee which has been contaminated with cow faeces (often used as a fuel source). The baby develops weakness, rigidity and inability to suck before developing generalised tetanic spasms.
Localised tetanus is a rare type of tetanus where there is localised muscle spasm in the same body region as the injury. Generalised tetanus may follow localised tetanus but the clinical course is usually better.
Cephalic tetanus is another rare form of tetanus which may follow otitis media or a wound involving the head. Unlike generalised tetanus, it involves flaccid paralysis (not spasm) of muscles innervated by cranial nerves and presents with dysphagia, facial palsy and diplopia from paralysis of extraocular muscles.
The diagnosis of tetanus is typically a clinical one. Differential diagnosis includes: hypocalcaemic tetany, acute dystonia, meningitis and strychnine poisoning.
5. Managing single notifications
Within 3 days of notification of a confirmed case begin follow-up investigation.
Within 5 working days of notification enter confirmed cases on NCIMS.
Email de-identified case details to the Communicable Diseases Branch, including results of investigations, within 5 working days of notification.
The response to a notification will normally be carried out in collaboration with the case's health carers. But regardless of who does the follow-up, PHU staff should ensure that action has been taken to:
- confirm the onset date and symptoms
- find out if the case or relevant care-giver has been told what the diagnosis is before beginning the interview
- seek the doctor's permission to contact the case or relevant care-giver
- review case management
- identify contributing factors.
Investigation and treatment
Treatment is supportive and often requires intensive care.
Ascertain tetanus immunisation history including whether a primary immunisation course has been completed and if and when booster immunisations were given. Most cases have either never been vaccinated or they have completed a primary series but have not had a booster in the preceding 10 years.
Cases of tetanus require treatment with tetanus immunoglobulin and tetanus immunisation as the quantity of antigen in an acute tetanus episode is too small to illicit an immune response.
The case or relevant care-giver should be informed about the nature of the infection and the mode of transmission.
Determine likely source of infection. High risk wounds include compound fractures, wounds contaminated with soil or manure, deep penetrating wounds, presence of foreign body (e.g. splinter), wounds involving extensive tissue injury or necrotic tissue such as burns or large contusions, injecting drug use, body piercing or surgical procedures, replacement of an avulsed tooth, otitis media (ear infections), dental infection, animal bites, abortion, and pregnancy. No cause is found in about one third of cases.
For any recent wounds, determine how wounds were managed. (e.g. wound irrigation, topical disinfection, surgical debridement, immediate versus delayed wound closure, antibiotic treatment such as penicillin or metronidazole).
Determine tetanus immunisation history and whether tetanus immunoglobulin and/or tetanus toxoid was given appropriately after a high risk wound.
Isolation and restriction