Pediatrics
Tetanus is an acute, fatal, severe exotoxin-mediated nervous system disorder characterized by muscle spasm. - Caused by the toxin-producing anaerobe, Clostridium tetani.
Tetanus is the only vaccine-preventable disease that is infectious but not contagious from person to person.
- C. tetani is a part of the normal flora in human and animal intestines and is disseminated through excreta.
- In spore form, they are hard and long-lasting in soil and dust.
- The contamination of wounds, unhygienic and improper handling of the umbilical cord in newborns, lack of hygienic habits, and aseptic care during and after delivery are the main risk factors for infection.
Pathogenesis
Tetanus occurs when spores of C. tetani found in soil gain access to damaged human tissue. After inoculation, C. tetani transforms into a vegetative rod-shaped bacterium and produces the metalloprotease, tetanospasmin. -⇒ After reaching the spinal cord and brainstem via retrograde axonal transport and binding tightly and irreversibly to receptors, tetanus toxin blocks neurotransmission. ⇒ The net effect is disinhibition of anterior horn cells and autonomic nervous system resulting in increased muscle tone, painful spasms, and widespread autonomic instability.
Predisposing Factors
- A penetrating injury – inoculation of C. tetani spores.
- Coinfection with other bacteria.
- Devitalized tissue.
- A foreign body.
- Localized ischemia.
Therefore tetanus develops in these clinical settings: neonates, obstetric patients, postsurgical patients, patients with dental infection, diabetic patients with infected extremity ulcers, patients who inject illicit and/or contaminated drugs.
Clinical Manifestations
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Incubation period: 1-8 days.
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Generalized tetanus:
- Presenting feature is trismus
- Symptoms of autonomic overactivity such as irritability, restlessness, sweating, tachycardia, cardiac arrhythmias, labile hypotension or hypertension, and fever.
- Tonic contractions of skeletal muscles (stiff neck, opisthotonus, risus sardonicus, board-like rigid abdomen) and intermittent intense muscular spasms with no impairment of consciousness.
- Painful spasms, triggered by loud noises or other sensory stimuli such as physical contact or light.
- Period of apnea and/or upper airway obstruction due to contraction of thoracic muscles and/or glottal or pharyngeal muscle.
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Neonatal tetanus:
- Manifested by rigidity, spasms, trismus, inability to suck, and seizures.
Diagnosis
Mainly clinical.
Treatment
Best in the ICU as the child may need early and aggressive airway management.
The goals of treatment include:
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Halting toxin production:
- Wound debridement.
- Antimicrobial therapy: metronidazole or penicillin G for 7-10 days.
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Neutralization of unbound toxin:
- HTIG (human tetanus ig)-3,000-6,000 units i.m.
- Equine antitoxin 1,500-3,000 units i.m. or i.v.
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Control of muscle spasms:
- Avoidance of sensory stimuli.
- Sedatives: diazepam.
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Management of autonomic dysfunction:
- Magnesium sulfate, beta blockers, morphine sulfate.
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Airway management and other supportive measures:
- Main treatment as bound tetanus toxin cannot be displaced from the nervous system.
- Endotracheal intubation/tracheostomy, nutritional support, physical therapy as soon as spasms have ceased.
Prevention
- Immunization and proper treatment of wounds and traumatic injuries.
Prognosis
- The average mortality of tetanus is 45-55%.
- Neonatal tetanus: 60-70%.
- The most important factor influencing outcome is supportive care.
Vaccine
- DTaP vaccine: 3 primary doses starting at 6 weeks of age (2 months in Saudi Arabia immunization schedule).
- 1st booster at 16-18 months of age, 2nd booster at 5 years of age.
- At 10 years of age Tdap/Td followed by Td every 10 years.
- Catch-up vaccination:
- Below 7 years: DTaP at 0, 1, and 6 months.
Surgery
Tetanus
Caused by Cl. Tetani as complication of wound contamination. Usually the wound is healed when the symptoms start to appear. Incubation period: One to three weeks.
Cl. tetani produces a neurotoxin that stimulates the nerves in spinal cord that leads to muscle spasm.
Prophylaxis:
- Wound care & antibiotics.
- Vaccination by tetanus immunoglobulin (Ig) in high-risk pts ( passive immunization).
Commence active immunization (T toxoid). In previously immunized pt., if the booster was:
-
5 years, the pt. needs another booster.
- < 5 years, no treatment.
Tetanus toxoid provides active immunization to those with known, complete tetanus immunization histories as well as those with unknown or incomplete histories. Human tetanus immune globulin (antitoxin) provides passive immunity by neutralizing circulating tetanospasmin and unbound toxin in a wound.