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Tetanus (lockjaw) results from the
absorption of the potent exotoxin produced by Clostridium tetani.
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(Dr Tsutsumi)
 This free-living saprophyte,
widespread in nature, especially in cultivated soil, is commonly found
in the faeces of cattle and horses and less commonly of humans.
It therefore tends to colonize manured
areas of cultivation. Once introduced into an area, spores of C.
tetani persist almost indefinitely. Tetanus is therefore particularly
a hazard in intensively cultivated rural areas.
Tetanus results from the introduction
of spores of C. tetani into tissue, where anaerobic conditions
favorable to germination and toxin production may be present.
Punctured wounds as from a nail or
splinter are particularly dangerous.
Tetanus was once a frequent
complication of abortion and was also commonly seen in infants as
tetanus neonatorum , which resulted from the infection of the
umbilical stump.
Active immunization has contributed to
a decline in the occurrence of tetanus.
Tetanus toxin is absorbed from the
local site of production and is transmitted into the central nervous
system along the axons of neurons.
Tetanus toxin is a potent
neurostimulatory agent.
Clinical features of tetanus may appear
several weeks or even months after the responsible injury, and in a
considerable number of cases no injury can be demonstrated or
recalled.
Symptoms begin with headache, followed
shortly by difficulty in swallowing and stiffness of the jaw.
Muscle stiffness or spasm may initially
be confined to the region of the local infection (local tetanus).
Spasm of the muscles of the trunk may
lead to opisthotonos.
Contraction of the facial muscles
produces the characteristic risus sardonicus.
Consciousness is undistributed, and
perception of pain is undiminished.
Death results from inanition or
secondary complications such as
bronchopneumonia
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Specific morphologic changes have not
been described.
A reliable diagnostic procedure is the
demonstration of muscle spasm in guinea pigs injected with wound
scrapings suspended in a saline solution.
The presence of tetanus bacilli
established by culture is not diagnostic, since spores of C. tetani
frequently contaminate wounds.
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