Clinical Tetanus

Objectives

This guideline outlines the diagnosis and management of clinical tetanus in the deployed environment. For risk assessment and treatment of a tetanus prone wound please see the relevant CGO.

Scope

This guideline applies to all echelons of deployed medical care.

Initial Assessment & Management

Background

Clinical tetanus is caused by Clostridium tetani, a ubiquitous spore forming soil bacterium which can infect wounds and produce a toxin which causes an unmistakable life threatening neurological syndrome. Since universal vaccination it is a rare disease in a UK population with <10 cases per year, typically in people who inject drugs, or older (>65) patients whose immunological protection through vaccination has waned. Universal vaccination in armed forces personnel since 1938 has essentially eliminated this as a threat to UK personnel, but a tetanus risk assessment should still be performed for individuals with wounds, and is covered in a separate CGO. Globally, tetanus still presents a significant public health challenge in unvaccinated individuals who receive a tetanus prone wound, and has been seen on operations. Neonatal tetanus, where infection of the umbilical cord stump in a newly born infant, still causes 60000 deaths per year and is commonest in SE Asia and Brazil.

Presentation

Typically 8 days (+/-3) after a tetanus prone wound generalised tetanus presents with muscle spasm, which can progress onto autonomic dysfunction several days later.

Spasms occur in a classic pattern with ‘lockjaw’ or risus sardonicus affecting the muscles of the face, and can prevent eating/drinking. Spasms of the back, thorax abdomen and extremities leads to an arched back position termed opisthotonus. These last several minutes, are often provoked by external stimuli such as pain, and are themselves painful. Respiratory compromise can occur, and spasms can progress for 10 days after the initial treatment.

Autonomic disturbance, along with breathing difficulty, is the most serious complication, with hypertension, tachycardia & hyperpyrexia which can last for several weeks.

Localised tetanus is where rigidity and spasm is limited to a small area, usually close to the wound. This may or may not progress to generalised tetanus, and while it does take weeks to recover, is not life threatening unless it progresses.

Neonatal tetanus only occurs in infants of unimmunised mothers and is characterised by an infant who initially feeds normally, but who subsequently becomes floppy, weak & irritable with an inability to feed usually a few days to a week after birth. Progression to opisthotonus and autonomic instability occurs over days with a high case fatality rate.

Diagnostic Confirmation

Tetanus is a clinical diagnosis, made by characteristic clinical findings described above, usually in the presence of a tetanus prone wound, which has become infected, in an unimmunised individual.  Neurological syndromes, including seizures & dystonia, rabies and hypocalcaemia are all on the differential diagnosis.

Tetanus can sometimes be cultured from the wound. This will only be available where a full diagnostic laboratory with wet culture is present, usually only at R3. A negative wound culture does not exclude tetanus.

Management

Any wound should be managed with debridement and antibiotics to prevent further spore germination and toxin production. Metronidazole and penicillin are effective, so deployed antimicrobial formulary recommended co-amoxiclav will work well.

Tentanus immunoglobulin should be administered intramuscularly at 150IU/kg (for human immunologlobulin) but may be difficult to source in deployed environments.

Generalised tetanus should be managed in an ITU environment, with care taken to minimise external stimuli which provoke spasms, including reduced lighting levels and a quiet environment. This may be difficult in a deployed ITU environment. Intubation to protect the airway is usually required, benzodiazepines for spasm and careful management of autonomic disturbance, often with labetalol. Intravenous magnesium is often helpful. 

Recovery is likely to be slow, with a prolonged ITU stay required, so disposal from a deployed environment into the civilian chain or to R4 should be considered at the earliest opportunity. 

Clinical tetanus is rare, and expertise in management limited so obtaining reach back support early is advised.

Any cases of clinical tetanus require an FMed85 and urgent notification to military Public Health.