Tetanus is the result of infection with Clostridium tetani, a spore-forming Gram-positive obligate anaerobe. It was first described by Hippocrates in the 5th century BC.
Spores are found in virtually all soil, particularly soil rich in manure, but also in house dust and both animal and human faeces. Spores can enter even the smallest wound, and in anaerobic conditions found in necrotic tissue, active infection or the presence of a foreign body produces tetanospasmin, a powerful exotoxin. This spreads via lymph and blood and is transported up the nerves, binding irreversibly to neurons and preventing inhibition of motor reflex responses to sensory stimuli. This results in the characteristic muscle spasms (severe enough to tear muscles, cause long-bone fractures or spinal compression fractures) and rigidity.
Incidence and mortality
Tetanus is rare in the UK. Seven cases of tetanus were identified in England between January and December 2014; no cases were reported from Wales.
It is largely a disease of the developing world and the poor, where there is inadequate vaccination.
The World Health Organization (WHO) estimates that in 2013 (the latest year for which estimates are available) about 49,000 newborns died from neonatal tetanus. This is a 94% reduction from the situation in the late 1980s.
Worldwide, 21 countries have yet to eliminate this disease.
- Age >60 years, lack of immunisation, poverty, drug addiction.
- Wounds contaminated with garden soil or manure and those caused by rusty metals are particularly dangerous.
- It can also complicate burns, ulcers, gangrene, snakebite, frostbite, otitis media, septic abortion, and childbirth.
- It can also occur following intramuscular (IM) injections in surgery.
- Tetanus neonatorum is associated with poor obstetric techniques. This is particularly the case with the practice of applying cow dung or clarified butter to the cut surface of the umbilical cord, in both Africa and India.
- Neonatal tetanus, which is mostly fatal, is particularly common in rural areas where deliveries are at home without adequate sterile procedures.
Incubation period is on average seven or eight days but can range from one day to two months. The shorter the incubation period, the worse the severity. The incubation period of neonatal tetanus is 3-10 days.
15-25% of cases show no evidence of recent wounds. Clinically, four forms are recognised:
- Generalised tetanus (80%) is usually a descending pattern after prodromal fever, malaise and headache:
- Trismus (lockjaw, an associated later feature: risus sardonicus, a grin-like expression from fixed facial muscle spasm).
- Neck stiffness (which may develop into opisthotonus: arched body with hyperextended neck).
- Swallowing difficulties.
- Abdominal muscle rigidity.
- Muscular spasms (initially reflexive, then spontaneous).
- Localised tetanus is uncommon, may precede generalised tetanus but, generally, is a self-limiting illness with painful muscle spasms localised to the site of injury.
- Cephalic tetanus is also uncommon, as it is usually secondary to otitis media or a head injury, exhibiting cranial (especially facial) nerve palsies and progressing to the generalised form if untreated.
- Neonatal tetanus is a form of generalised tetanus in the newborn lacking passive immunity from a non-immune mother, infected usually via the umbilical stump, through lack of antiseptic practice and application of 'local remedies' (see Risk factors, above). It presents with inability to suck, irritability, grimaces, and rigidity with spasms.
Complications in severe generalised tetanus:
- Aspiration pneumonia.
- Laryngospasm, which may lead to asphyxia.
- Fractures from sustained contractions and convulsions.
- Respiratory embarrassment with tachypnoea, and intermittent apnoea.
- Autonomic nervous involvement leading to hypertension, dysrhythmias and cardiac arrest.
- Tetanic seizures mimicking epilepsy - frequency and severity related to the severity of illness, and indicate poor prognosis.
- Pulmonary embolus particularly in drug abusers and the elderly.
There is no specific diagnostic laboratory test; diagnosis is made clinically. The spatula test is useful: touching the back of the pharynx with a spatula elicits a bite reflex in tetanus, instead of a gag reflex.
Early diagnosis and intervention can be life-saving. Patients should be treated in an intensive care unit.
Seek expert help quickly, as toxin fixed to neurons cannot be neutralised by antitoxin. Any recovery of nerve function requires regrowth and formation of new synapses.
- Give human tetanus immunoglobulin (antitoxin) intravenously (IV) before any other action.
- Delay local debridement (until a few hours after immunoglobulin has been given, because of the risk of release of further toxin) to remove organisms, and create an aerobic environment.
- Penicillin may be used but its results are disappointing. Metronidazole may be used as an alternative and its use may be associated with lower mortality.
- Most patients should be considered for prophylactic sedation and intubation.
- Benzodiazepines are often administered to prevent or control spasms.
- Botulinum toxin may reduce tetanus symptoms.
- Some patients will require a tracheostomy.
- Autonomic disturbance requires appropriate treatment.
The muscle stiffness and ankle clonus can last for months after recovery and significant weight loss is always seen. Signs that are significantly associated with increased mortality are:
- Older age (especially >60 years).
- Shorter duration of symptoms - trismus, rigidity and dysphagia.
- Severe disease at presentation.
- Shorter period of onset.
Prevention of tetanus
Tetanus infection does not confer immunity; immediate vaccination (inactivated tetanus toxoid) is too slow to address a current infection. Antibiotic prophylaxis against tetanus in wound management is not indicated. Active infection should be treated appropriately.
Prevention of neonatal tetanus is possible by the vaccination of pregnant or non-pregnant women, or both, with tetanus toxoid and by the provision of clean delivery services.
Because of concern at the low levels of immunity to diphtheria in older people in the UK, and the switch to inactivated polio vaccine (IPV), tetanus vaccine is now only given as part of combined products:
- 'Standard' tetanus/diphtheria/inactivated polio vaccine (Td/IPV) - used for adults and school leavers.
- Primary course for those aged under 10 years: diphtheria/tetanus/acellular pertussis/inactivated polio vaccine/Haemophilus influenzae type b (DTaP/IPV/Hib).
- 'Pre-school booster': diphtheria/tetanus/acellular pertussis/inactivated polio vaccine(DTaP/IPV or dTaP/IPV).
Vaccines are normally given IM into the upper arm or anterolateral thigh, except if patients have a bleeding disorder (eg, haemophilia) when deep subcutaneous injection is appropriate.
The objective of the immunisation programme is to provide a minimum of five doses of tetanus-containing vaccine at appropriate intervals for all individuals.
For the majority of cases, a total of five doses of vaccine at the appropriate intervals is considered to give satisfactory long-term protection.
The UK schedule for primary immunisation is as follows:
- Children aged under 10 years: at 2, 3 and 4 months of age. Those who miss a dose need to resume the schedule but do not need to have repeat doses. There should be a minimum for one month in between doses of the vaccine.
- Children aged over 10 years and adults: the primary course is three doses with an interval of at least one month in between doses. Those who miss a dose need to resume the schedule but do not need to have repeat doses.
The UK schedule for reinforcing immunisation is as follows:
- Children aged under 10 years: should receive the first booster (combined with diphtheria, pertussis and polio vaccines as the pre-school booster) three years after completion of the primary course.
- Children aged over 10 years and adults: should receive the first tetanus booster combined with diphtheria and polio vaccines at least five years after their primary course.
- The second booster (Td/IPV) should be given to all people ten years after their first booster vaccine.
- NB: booster doses should be given to IV drug users who are uncertain about their immunisation status, as they are at a greater risk of tetanus.
Vaccination of children with unknown or incomplete immunisation status
- A child who has not completed the primary course should have the outstanding doses at monthly intervals.
- Children may receive the first booster dose as early as one year after the third primary dose, to re-establish them on the routine schedule.
- The second booster should be given at the time of leaving school to ensure long-term protection by this time, provided a minimum of five years is left between the first and second boosters.
- Children coming to the UK, who have a history of completing immunisation in their country of origin, may not have been offered protection against all the antigens currently used in the UK.
- Where there is no reliable history of previous immunisation, it should be assumed that they are unimmunised, and the full UK recommendations should be followed.
- Children coming to the UK may have had a fourth dose of a tetanus-containing vaccine that is given at around 18 months in some countries. This dose should be discounted, as it may not provide satisfactory protection until the time of the teenage booster. The routine pre-school and subsequent boosters should be given according to the UK schedule.
Travellers to remote areas
For travellers to areas where medical attention may not be accessible and whose last dose of a tetanus-containing vaccine was more than ten years previously, a booster dose should be given prior to travelling, even if the individual has received five doses of vaccine previously. This is in case immunoglobulin is not available to the individual should a tetanus-prone injury occur.
Contra-indications to tetanus vaccination
- Confirmed anaphylactic reaction to previous tetanus vaccine.
- Confirmed anaphylactic reaction to neomycin, streptomycin or polymyxin B.
Stable neurological conditions, febrile convulsions and personal or family history of seizures are not contra-indications.
Immunisation should be deferred if the child is unwell with fever (vaccinate as soon as possible once the child has recovered).
Fever, hypotonic-hyporesponsive episodes (HHEs), persistent crying or severe local reaction within 72 hours of previous vaccination are not reasons for not giving subsequent tetanus vaccinations.
Tetanus vaccines can be safely given to those women who are pregnant or breast-feeding.
Side-effects of vaccine
Report adverse reactions to the Commission on Human Medicines (CHM) via the Yellow Card Scheme.
- Pain, redness and swelling are common.
- Transient nodule at injection site.
- Anaphylaxis is extremely rare.
Management of patients with tetanus-prone wounds
Tetanus-prone wounds are:
- Wounds or burn sustained >6 hours before surgical treatment.
- Any wound or burn with:
- A significant degree of devitalised tissue or puncture wounds, especially where there has been contact with soil or manure.
- Foreign bodies.
- Compound fractures.
- Clinical evidence of sepsis.
- Thorough cleaning of wounds is essential.
- If the risk of tetanus is especially high - eg, the wound is contaminated with stable manure - human tetanus immunoglobulin should be given to give immediate additional protection. This should be done regardless of the patient's immunisation history.
- Where the individual has received a full five-dose course of tetanus vaccine at the recommended intervals, or is up-to-date with their tetanus immunisation schedule, no further doses of vaccine are recommended.
- If the immunisation schedule is not up-to-date or its status is unknown, a reinforcing dose of Td/IPV should be given at the time of treatment of an injury and further doses given as required to complete the recommended five-dose schedule.
- Patients who are immunosuppressed may not be adequately protected against tetanus, despite having been fully immunised. They should be managed as if they were incompletely immunised.
Further reading and references
Immunizations - childhood; NICE CKS, July 2016 (UK access only)
Immunizations - travel; NICE CKS, October 2016 (UK access only)
Infection report/Immunisation: Tetanus in England and Wales: 2014 -Volume 9 Number 18; Public Health England, 22 May 2015
Immunization, Vaccines and Biologicals: Tetanus; World Health Organization, 2016
Demir NA, Sumer S, Ural O, et al; An alternative treatment approach in tetanus: Botulinum toxin. Trop Doct. 2015 Jan45(1):46-8. doi: 10.1177/0049475514550063. Epub 2014 Sep 18.
Verweij M, Lambach P, Ortiz JR, et al; Maternal immunisation: ethical issues. Lancet Infect Dis. 2016 Dec16(12):e310-e314. doi: 10.1016/S1473-3099(16)30349-8. Epub 2016 Sep 20.