TETANUS / MedUrgent

 


TETANUS




Tetanus is an acute toxemic illness caused by a soluble exotoxin of the obligate anaerobic bacterium Clostridium Tetani. The toxin is produced by the vegetative forms of the organism at the site of injury and it enters the bloodstream and subsequently is fixed within the central nervous system.

 It is a spore forming gram positive bacillus which converts into vegetative forms in the wounds and produce the exotoxin tetanospasmin that binds to gangliosides at the myoneural junction of skeletal muscles and on neural membranes in the spinal cord blocking the inhibitory pulses to motor neurons that leads to spastic paralytic illness. 

It affects all age groups including adults as occupational hazards e.g. farmers. The incubation period varies from 2-14 days to months after the injury. 

In Sudan, it has 2 peaks, the neonatal period or at the age of around 7 years in female children following circumcision. Eradication of neonatal tetanus is declared by WHO and UNICEF as one of the priorities and a number of activities have been done in all regions but specifically in developing countries where the disease is common.


Clinical presentations

 Tetanus in children and adults may be localized or generalized and has the following presentations:

1. Localized tetanus:

At the site of injury or infected wound where there is pain, continuous rigidity and spasm of muscles near the site of injury and may precede generalized tetanus.

2. Cephalic tetanus:

It occurs secondary to injury of the head or face or otitis media. It leads to palsy of the cranial nerves 3, 4, 7, 9, 10 and 11. It leads to retracted eyelids, deviated gaze, trismus, risus sardonicus and spastic paralysis of tongue and laryngeal muscles. 

3. Tetanus neonatorum:

It occurs commonly secondary to infected umbilical stumps due to unhygienic handling of the cord or application of animal dander over the stump. It presents with difficulty in suckling, dysphagia, opisthotonus and tetanic generalized spasms. It is a form of generalized tetanus

4. Generalized tetanus:

This is the most common form. It presents with restlessness, irritability, trismus (lockjaw), dysphagia, headache, risus sardonicus followed by generalized tetanic spasms, opisthotonus and rigidity of the abdominal muscles. Autonomic involvement presenting with spasm of laryngeal and respiratory muscles that leads to suffocation, hypertension, tachycardia and cardiac arrhythmias. It is associated with low grade fever, hyperhidrosis and urine retention. During these very painful muscular spasms, consciousness is maintained. Spasm may recur every few minutes or become sustained. The attacks may be precipitated by any external stimuli e.g. light, touch and sounds. Death may occur due to asphyxia or cardiac failure.






Diagnosis and investigations

• Clinical diagnosis is most important

 • C. tetani is not always positive on gram stains of wounds or Culture.


Treatment

• Human tetanus immunoglobulin (TIG) to neutralize the toxin: 3,000-6,000 units IM. TIG may be infiltrated around the wound but it is not always effective

• Penicillin: 100,000 - 200,000 U /kg/day IV in 4 divided doses for 10-14 days is the drug of choice. Erythromycin and for adults tetracycline in penicillin sensitive subjects may be used. Bovine tetanus antitoxin 50,000-100,000 U in a single dose after testing hypersensitivity may be given.

 • Metronidazole 30mg/kg/day in 4 divided doses may be added to reduce the number of vegetative forms of C.tetani 

• Surgical wound care should be done promptly after administration of TIG

Wounds should be left open due to the anaerobic nature of the organism 

• Supportive care to reduce muscle spasms: 

keep the patient in a quiet dark room 

• Sedation: Diazepam 0.1 -0.2 mg/kg every 3-6 hours IV to control tetanic spasms. 

Other drugs used are chlorpromazine and magnesium sulfate. 

• Nutritional support: Nasogastric and endotracheal tubes should be used with care as they may precipitate severe laryngeal spasm. 

• Tracheostomy, mechanical ventilation, and muscle relaxants may become necessary in severe intractable cases. Autonomic instability may be controlled by alpha and Beta blocking agents.

 • Start immunization as an attack does not confer immunity against further attacks.


Prevention

 • Tetanus is a preventable disease by active immunization beginning in infancy using DPT followed by booster doses and through adult life with DT or tetanus toxoid in prone individuals. 

• WHO is currently engaged in a global elimination of neonatal tetanus through maternal immunization of at least 2 doses of tetanus toxoid during pregnancy.

 • Wound care: surgical cleansing and debridement to remove foreign bodies and any necrotic tissue 

Antitoxin and toxoid should be given simultaneously.

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