Tetanus
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Tetanus is caused by the tetanospasmin exotoxin released from Clostridium tetani. Tetanus spores are present in soil and may be introduced into the body from a wound, which is often unnoticed. Tetanospasmin prevents release of GABA
Pathophysiology
C. tetani spores germinate in anaerobic conditions, releasing tetanospasmin. This toxin interferes with neurotransmitter (GABA) release, leading to muscle rigidity and spasms. Initial symptoms often include stiffness in the jaw (lockjaw) and neck, progressing to generalised muscle stiffness.
adjuvant, either aluminium phosphate or aluminium hydroxide, to improve its immunogenicity.
Tetanus vaccines used for primary immunisation contain not less than 40IU of tetanus toxoid; vaccines used for boosters contain not less than 20IU.
The tetanus vaccine is only given as part of combined products for the UK national vaccination programme:
Early recognition and treatment are vital due to the high mortality rate associated with tetanus. Healthcare professionals should be vigilant for symptoms, particularly in unvaccinated individuals or those with uncertain immunization status.
High-risk tetanus-prone wounds include: Any of the above with either:
Clinical features
- prodrome fever, lethargy, headache
- trismus (lockjaw)
- risus sardonicus
- opisthotonus (arched back, hyperextended neck)
- spasms (e.g. dysphagia)
Pathophysiology
C. tetani spores germinate in anaerobic conditions, releasing tetanospasmin. This toxin interferes with neurotransmitter (GABA) release, leading to muscle rigidity and spasms. Initial symptoms often include stiffness in the jaw (lockjaw) and neck, progressing to generalised muscle stiffness.
Epidemiology
Tetanus incidence has significantly decreased in countries with comprehensive immunization programs. However, it remains a concern in areas with low vaccination coverage. Neonatal tetanus, resulting from umbilical stump infections, is a notable cause of infant mortality in some regions.Prevention
Immunization is the most effective preventive measure. In the UK, the routine vaccination schedule includes five doses of tetanus-containing vaccine, starting in infancy.Tetanus vaccine
In the UK tetanus vaccine is made from a cell-free purified toxin extracted from a strain of C. tetani. This is treated with formaldehyde that converts it into tetanus toxoid. This is adsorbed onto anadjuvant, either aluminium phosphate or aluminium hydroxide, to improve its immunogenicity.
Tetanus vaccines used for primary immunisation contain not less than 40IU of tetanus toxoid; vaccines used for boosters contain not less than 20IU.
The tetanus vaccine is only given as part of combined products for the UK national vaccination programme:
- diphtheria/tetanus/acellular pertussis/inactivated polio vaccine/Haemophilus influenzae
- diphtheria/tetanus/acellular pertussis/inactivated polio vaccine (DTaP/IPV or dTaP/IPV)
- tetanus/diphtheria/inactivated polio vaccine (Td/IPV)
Management of suspected cases
Management involves the following steps:- ABCDE approach to ensure airway is secure and circulatory system supported as needed
- IV access and send blood for CK, tetanus toxin and serology
- Immediate thorough cleaning of contaminated wounds (tetanus-prone injuries) with early wound debridement
- Administration of human IV tetanus immunoglobulin (TIG) is recommended to provide passive immunity OR IVIG (see box below)
- Antibiotics using agents reliably active against anaerobes e.g. intravenous benzylpenicillin or metronidazole
- Vaccination with tetanus toxoid following recovery
- Supportive measures including benzodiazepines for muscle spasms, treatment of autonomic dysfunction, maintenance of ventilation, nursing in a quiet room.
Tetanus immunoglobulin
The mainstay of treatment for tetanus prone wounds is tetanus immunoglobulin (TIG), however this has recently not been available in the UK. If TIG is not available then intravenous immunoglobulin (IVIG) may be used, at a dose of 5,000 units in patients under 50kg, and 10,000 units in those over.Early recognition and treatment are vital due to the high mortality rate associated with tetanus. Healthcare professionals should be vigilant for symptoms, particularly in unvaccinated individuals or those with uncertain immunization status.
Tetanus-prone wounds
Tetanus-prone wounds include:- puncture-type injuries acquired in a contaminated environment and likely therefore to contain tetanus spores e.g. gardening injuries
- wounds containing foreign bodies
- compound fractures
- wounds or burns with systemic sepsis
- certain animal bites and scratches - although smaller bites from domestic pets are generally puncture injuries animal saliva should not contain tetanus spores unless the animal has been routing in soil or lives in an agricultural setting
High-risk tetanus-prone wounds include: Any of the above with either:
- heavy contamination with material likely to contain tetanus spores e.g. soil, manure
- wounds or burns that show extensive devitalised tissue
- wounds or burns that require surgical intervention that is delayed for more than six hours are high risk even if the contamination was not initially heavy