Tetanus

What is it? 

Tetanus is caused by infection with the bacteria Clostridium Tetani. The bacteria secrete a potent exotoxin that enters the bloodstream, acting on the central nervous system to cause muscle rigidity and painful spasms. Tetanus can be fatal when the muscles controlling respiration are affected. 

What to look for 

The incubation period of tetanus is 3 to 21 days. The most common time frame for presentation of tetanus is around 14 days after exposure. Although, it can present as early as 1 day or as long as several months after the exposure. 

The initial symptom is muscle rigidity. This can affect all muscles in the body but may be more pronounced in those closest to the site of the injury. In some cases, symptoms may include hyperreflexia (hyperactive reflexes) resulting in back, neck or limb stiffness; trismus (lockjaw); or sardonic smile (dystonia, or involuntary muscle contractions, producing a fixed smile). As the disease progresses, painful muscle spasms occur, affecting any muscles simultaneously. When spasms and rigidity affect the respiratory or laryngeal muscles, sedation and/or prolonged ventilation in the intensive care setting is required. Examples of complications of tetanus include hypertension (high blood pressure), hypotension (low blood pressure), respiratory failure, cardiac arrythmias (irregular heartbeat), pneumonia, fractures, muscle rupture, deep vein thrombophlebitis, pulmonary emboli, decubitus ulcers and rhabdomyolysis. In severe cases, tetanus can be fatal.

How is it transmitted?

Tetanus spores are found in dirt, dust and animal faeces. They can survive in the environment for many years.  Spores can be introduced into the body via a wound where the bacteria can grow and cause infection. Spores can survive in a wound for as long as 3 months before becoming active.  

Tetanus can occur following a significant wound or after trivial or even unnoticed wounds. Examples of wounds that are considered tetanus-prone include: 

• bites, either animal or human 
• deep penetrating wounds 
• minor lacerations, for example, from cat scratches, rose thorns, glass or other foreign bodies (e.g. splinters) 
• contusions or burns 
• compound (open) fractures 
• cuts or lacerations with outdoor equipment 
• tooth reimplantation post avulsion (knocked out tooth) 
• IV drug use sites. 

Tetanus cannot be passed directly from person to person.   

Epidemiology 

The incidence of tetanus is rare in Australia. Since 2001, there have been fewer than 8 cases reported each year, with a total of 84 cases since 2000. The case fatality rate in Australia is about 2%. Globally, tetanus is fatal in approximately 11% of reported cases. 

Tetanus can affect people of any age. However infections in Australia are more commonly seen in older adults who have never been vaccinated or were vaccinated more than 10 years ago.  

In countries with low rates of vaccination, Maternal and Neonatal Tetanus (MNT) remains a common life-threatening consequence of unhygienic deliveries and umbilical cord care practices. Mortality rates associated with MNT are extremely high, especially when appropriate medical care is not available, as is often the case.

Prevention 

Vaccination is the most effective way to prevent tetanus. Vaccines target the tetanus toxin (toxoid) and, in Australia, are available only in combination with diphtheria. Vaccines may also include other antigens, such as pertussis, inactivated poliovirus, hepatitis B and haemophilus influenzae type B. 

Table: Which tetanus-toxoid containing vaccine to use by age of patient 

Tick = recommended for use in this age group
Grey shading = not routinely recommended for use in this age group
* ATAGI recommends the use of Infanrix hexa and Vaxelis in children aged < 10 years, however the Royal Children’s Hospital (RCH) preferentially uses them up to < 18 years in instances where multiple vaccines are required (eg. catch up, post chemotherapy/post HSCT). 

Primary course  

As per the National Immunisation Program (NIP), a primary course of tetanus vaccination is given at 6 weeks, 4 months, and 6 months of age (Infanrix hexa/Vaxelis). 

Boosters 

Booster doses are scheduled to be administered at: 

• 18 months (Infanrix/Tripacel) 
• 4 years (Infanrix-IPV/Quadracel) 
• 12 to 13 years of age/year 7 high school program (Boostrix) 

Regular booster doses every 10 years are no longer routinely recommended. However, women who receive the recommended pertussis vaccine during every pregnancy will also receive a booster of tetanus (and diphtheria). Adults aged ≥ 50 years who have not received a dose of tetanus-containing vaccine in the last 10 years should consider a booster dose (unfunded).
Those who have a tetanus-prone wound should also receive a booster if they have not received a dose of tetanus-containing vaccine in the last 10 years (see Tetanus-prone wounds below). 

Catch up 

Any person with an incomplete tetanus immunisation history should be offered catch up. Refer to MVEC: Catch up immunisation for specific guidance.  

Tetanus-prone wounds 

The correct management of a tetanus-prone wound is vital for the prevention of tetanus infection.  

Initial treatment involves cleaning and disinfecting the wound. Medical review by a GP or emergency department is recommended.  

Reviewing a person’s immunisation history will inform tetanus-prevention management, which may include vaccination and/or the administration of immunoglobulin. Immunoglobulin provides short-term protection against tetanus. Vaccines provide longer and ongoing protection against the development of disease.  

Regardless of the nature of the wound, all unimmunised individuals, partially immunised individuals(those who have received less than 3 doses of a tetanus-containing vaccine) and immunocompromised individuals are at the greatest risk of contracting tetanus.  

Groups who are often assumed to be up to date, but may lack optimal vaccine protection, include:

• those aged between 9-13 years, as they are 5 + years post their 4-year-old vaccine and may not have yet received their Year 7 booster
• the elderly population, due to waning immunity and time passed since last booster. 

Table: Guide to tetanus-prevention management  

Tick =  required
Shaded boxes = not required
¥ Using age-appropriate tetanus-containing vaccine (see above Table: Which tetanus-toxoid containing vaccine to use by age of patient)
*administration of immunoglobulin is recommended when the patient has humoral immune deficiency or HIV (regardless of CD4+ count)
^ where there is no documented history of a completed 3-dose primary course of tetanus vaccination patients should receive all missing doses AND tetanus immunoglobulin. 

Vaccine side effects 

Injection site reaction (ISR) is a common side effect after receiving a tetanus-toxoid vaccine. Uncommon side effects include headache, lethargy, irritability, body aches and fever. These side effects are usually self-limiting and resolve within 48 hours.

Resources

• Australian Immunisation Handbook: Tetanus
• The Royal Children’s Hospital Clinical Practice Guideline: Management of tetanus prone wound
• Australian Government Department of Health and Aged Care: Changes to the National Immunisation Program schedule from July 1 2023