-Like other clostridia, it is an anaerobic, spore-forming, gram-positive rod
-it produces a deadly toxin which disrupts central inhibitory neurotransmission, resulting in increased muscle tone and spasms
Symptoms & signs
-tonic contraction of voluntary muscles; spasms of the muscles of the jaw (trismus, lockjaw), inability to open the mouth; fully conscious patient; a characteristic grimace (risus sardonicus), exaggerated reflexes, spasms of the extensor muscles of the back resulting in a pronounced arching of the back (Opisthotonus); respiratory failure
Tetanus vs Botulism: in tetanus spastic paralysis (strong muscle contractions) occurs, whereas in botulism, flaccid paralysis (weak or absent muscle contractions) occurs. In tetanus, bacteria inhibit glycine release, in botulism, bacteria inhibit acetylcholine release.
Diagnosis
-Tetanus is a clinical diagnosis
-Suspect it in all patients with muscle spasms and an inadequate vaccination history
-Wound culture may show bacteria with one terminal spore at the end of the rod (tennis racket shape)
Treatment
-Tetanus is a toxin mediated disease, so goals should be to eliminate current toxin production using antibiotics and vaccination and to neutralize unbound toxin with human tetanus immune globulin
-Natural disease does not induce immunity, so immunize all recovering patients
-Supportive care using muscle relaxants and ventilation
- What is the most common cause of death in tetanus? respiratory failure