Tetanus

Notification requirement for tetanus

Tetanus is a 'routine' notifiable condition. It must be notified by medical practitioners and pathology services in writing within 5 days of diagnosis.

This is a Victorian statutory requirement.

Primary school and children's services exclusion for tetanus

Exclusion is not applicable.

Infectious agent of tetanus

Tetanus is caused by Clostridium tetani (C. tetani), an anaerobic gram-positive bacterium.

Identification of tetanus

Clinical features

Tetanus is an acute, potentially fatal disease caused by C. tetani bacteria multiplying at the site of an injury. The bacteria produce potent toxins (tetanus toxin) that can enter the blood stream and lymphatic system and spread throughout the body, acting on the sympathetic nervous system and several sites within the central nervous system. This leads to unopposed muscle contraction and spasm.

Multiple different forms of tetanus can occur.

Generalised tetanus is the most common form of the disease. Most cases present due to lockjaw, also known as trismus (masseter spasm that prevents mouth opening normally) or risus sardonicus (a tightening of facial muscles causing grimacing/sardonic smile). People may also present with sweating and/or tachycardia.

As the condition progresses, people can develop widespread painful muscle spasms and contractions. Contractions can cause upper airway obstruction and apnoea, which can threaten respiratory status and is responsible for many of the tetanus complications.

Local tetanus can present with contractions and spasms in one extremity or body region. This usually progresses to generalised tetanus.

Cephalic tetanus can occur in cases with injuries to the head or neck; initially only the cranial nerves are affected. As with local tetanus, it usually progresses to generalised tetanus.

Neonatal tetanus can occur when the umbilical stump is infected, such as through administration of unconventional substances (for example, juices, butter/ghee, faecal matter), and in infants born to mothers who are unimmunised. It typically occurs in the first week (5 to 7 days) following birth. Babies may present with refusal to feed and difficulties opening their mouths, in an infant previously able to feed and cry normally. Contractions in other muscle groups can follow, such as clenching of hands, flexion of feet, and eventually rigidity of the spine.

Most forms of tetanus take 4 to 6 weeks to recover due to the need for new axonal nerve terminals to grow.

Complications

Complications from tetanus generally arise from prolonged hospitalisation and airway support.

They can include secondary infections, pulmonary embolism and muscle atrophy. Severe complications include:

• fractures from severe muscle spasms
• respiratory failure
• hypertension
• hypotension
• cardiac arrhythmias
• death.

Death from tetanus is now uncommon in Australia but does occur in other parts of the world. Prognosis is generally poorer if there is rapid progression to generalised seizures from onset, and in the people over 70 years of age.

Diagnosis

Tetanus is usually diagnosed based on clinical assessment, including presentation, medical (including immunisation) and exposure history, rather than laboratory testing.

Laboratory confirmation of tetanus infection is often difficult.

C. tetani antibodies are sometimes detectable in serum samples but may result from waning past immunisation. Cultures from the site of infection should be attempted, although the organism is often not recovered.

Toxin gene testing may be performed on C.tetani isolates cultured from wounds. Clinicians should discuss the need for toxin gene testing with the Microbiological Diagnostic Unit (Public Health Laboratory) and your Local Public Health Unit.

Incubation period of Clostridium tetani

The incubation period is usually 3 to 21 days, although it may range from one day to several months, depending on the nature of exposure. Most cases occur within 8 to 10 days after injury/ inoculation.

Cases with shorter incubation periods tend to be associated with a heavily contaminated wound and severe disease, and thereby a greater risk of death.

Reservoir for Clostridium tetani

C. tetani is widely distributed in cultivated soil, and in the gut of humans and animals. Spores can usually be found wherever there is contamination with soil, dust and/or animal faeces. It can also be found on the surfaces of the skin, and rusty tools like nails, needles and barbed wire.

Mode of transmission of Clostridium tetani

Tetanus is not directly transmitted from person to person.

Tetanus spores found in the environment may be introduced through a break in the skin. Examples may include:

• contaminated puncture wounds (for example, penetrating wound from a rusty nail, rose thorn, injecting drug use)
• wounds contaminated with soil, manure, or foreign objects
• bite wounds (for example, human or animal bites including snake bites)
• compound fractures
• lacerations, burns or frostbite.

Tetanus can also result from minor wounds that are considered too trivial for medical consultation.

The presence of necrotic tissue or foreign bodies encourages the growth of anaerobic organisms such as C. tetani. Tetanus rarely follows surgical procedures today.

Period of communicability of tetanus

Spores are resistant to drying, heat and antiseptics, and may remain viable for many years in the environment.

Susceptibility and resistance to tetanus

Anyone who sustains a tetanus-prone wound and is not up to date with their tetanus immunisations may be at risk – particularly people who have never received a tetanus immunisation.

Protection from vaccination wanes over time. Active immunity can persist for up to 10 years, following a complete course of tetanus immunisations.

Transient passive immunity follows injection of tetanus immunoglobulin (TIG).

Recovery from tetanus is not necessarily associated with immunity. Therefore, keeping up to date with tetanus immunisations is important.

Other risk factors for tetanus include:

• being 70 years or older
• having diabetes
• having an immunocompromising condition
• injecting drugs.

Public health significance and occurrence of tetanus

Tetanus occurs worldwide, but is now rare in developed countries because of high immunisation rates.

Tetanus is still common in developing countries with lower immunisation rates and where contact with animal faeces is more common. Tetanus, particularly neonatal tetanus, is a significant cause of death in these settings.

It is estimated that tetanus causes 213,000–293,000 deaths worldwide each year, and is responsible for 5–7% of all neonatal deaths and 5% of maternal deaths globally.

Tetanus remains rare in Australia and the number of annual notifications has remained stable since 2005. It can occur at any age, but in Australia, it is mainly seen in adults who have never been vaccinated or who were vaccinated more than 10 years ago.

People who inject drugs are at risk of tetanus and may be linked to localised clusters, as reported in the United States and United Kingdom. Transmission of C. tetani in these settings can occur through contaminated drugs, its adulterants, injection equipment and unwashed skin.

Control measures for tetanus

Preventive measures

Wound care to prevent tetanus infection

Any wound other than a clean, minor cut should be considered 'tetanus- prone' and will need immediate treatment. Certain types of injuries can promote the growth of C. tetani, including:

• compound fractures (fractures with skin breakage)
• bite wounds (human or animal, including snakebites)
• deep penetrating injuries
• wounds containing foreign objects (especially wood splinters)
• wounds compounded by pyogenic infections
• injuries with significant tissue damage (contusion or burns)
• any superficial wound visibly contaminated with soil, dust or horse manure (particularly if not disinfected within 4 hours)
• reimplantation of an avulsed tooth, as minimal washing and cleaning are done to enhance reimplantation success
• injecting drugs.

Wounds should be assessed, cleaned and disinfected. In some instances surgical treatment may be appropriate.

The use of tetanus-toxoid vaccine in the management of wounds, with or without tetanus immunoglobulin (TIG), is determined by considering the vaccination history of the person and the nature of the wound.

For further information on tetanus prophylaxis in the management of bites and other tetanus-prone wounds, consult the current edition of the Australian Immunisation Handbook and the Therapeutic Guidelines.

Antibiotics do not prevent or treat tetanus, but may be utilised to prevent other bacterial contaminants in the wound.

Immunisation

Immunisation is an important preventive measure against tetanus as it reduces the risk of infection.

However, protection can be incomplete and wanes over time. People are recommended to stay up to date with their vaccinations, including booster doses, and should seek medical attention promptly if they have a tetanus-prone wound.

In Australia, tetanus-toxoid vaccine is only available in combination with other agents, such as diphtheria and pertussis. Combination vaccines may also include inactivated poliovirus, hepatitis B and haemophilus influenzae type b.

Free tetanus-containing vaccine is available through the National Immunisation Program schedule for:

• infants at 2 (can be given from 6 weeks of age), 4 and 6 months of age
• children at 18 months and 4 years of age
• adolescents in year 7 (or age equivalent)
• pregnant people in every pregnancy between 20 to 32 weeks gestation (to reduce the risk of pertussis disease in infants)
• any person under 20 years of age – catch up immunisation are available for anyone who has not been fully vaccinated
• refugees, asylum seekers and other humanitarian entrants of any age

Catch up immunisation are available for people who have not been fully vaccinated.

Adult immunisation

Adults aged 50 years or older are recommended to receive a tetanus booster dose if they have not received one in the past 10 years.

Vaccination is also recommended every 5 to 10 years for travellers to countries where health services may be difficult to access. These types of booster doses are not funded under the National Immunisation Program.

Adults of any age who need a tetanus-containing vaccine can have a combined diphtheria, tetanus and pertussis (dTpa) vaccine rather than a diphtheria and tetanus (dT) vaccine. This is especially important if they have not previously had a diphtheria, tetanus and pertussis vaccine dose in adulthood.

For further information on tetanus vaccination, particularly with respect to the management of children who have missed doses or tetanus-prone wounds prophylaxis, consult the current edition of The Australian Immunisation Handbook.

Control of case

Anyone suspected or confirmed with tetanus should be immediately referred to the nearest hospital. Patients often require admission to intensive care facilities for airway management. Tetanus treatment involves several types of medications and supportive care, and may include:

• TIG
• antibiotic therapy wound management and debridement
• controlling muscle spasm and maintaining an adequate airway
• case investigation to determine the circumstances of injury
• active tetanus immunisation provided concurrently with treatment.

Clinicians should advise cases of the nature of the infection, its mode of transmission, and ways to minimise the risk of re-infection.

Control of contacts

Not applicable.

Control of environment

Not applicable.

Outbreak measures for tetanus

Not applicable.