ARS Pacific Northwest District
Basic Facts About Tetanus
The tetanus bacterium clostridium tetani, a
cousin of the botulism organism, produces a toxin 50 times as poisonous
as cobra venom and 150 times stronger than strychnine. A wound no
larger than a pin prick can harbor enough bacteria to produce sufficient
toxin to kill an unvaccinated human. An amount of purified tetanus
toxin weighing no more than the ink in the period at the end of this
sentence would be enough to kill 30 grown men. It is one of the
most deadly poisons known to man. A natural habitat of this
bacterium is soil.
The cause of tetanus is not the bacterium itself, but the toxin which it
produces. Since it is an anaerobe (meaning that it can thrive only
in locations where there is no oxygen) it causes trouble when introduced
into a wound where it is cut off from an air supply. That's why
puncture wounds are a potential problem. Their very nature is to
close up and keep out the air. However, even a superficial scratch
is susceptible to the infection. The bacteria usually begin to
multiply right away after finding the airless environment, but the
spores can remain dormant, resulting in infection many years later.
Whenever infection develops, the prognosis is grim.
Anti-tetanus shots should be viewed as a necessity for those who may
have skin breaks and are likely to be in contact with soil. For
the non-immunized person simply trying to grow roses, a relatively
minor-seeming puncture as from a thorn, if done in the presence of
bacterial contamination on the thorn (from soil) can result in serious
A simple immunization once every 5-10 years is all that's recommended.
Your doctor can advise the best frequency for you, depending on your
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November 08, 2004
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