The bacteria that cause tetanus, Clostridium tetani, are found in soil, dust and animal feces. When they enter a deep flesh wound, spores of the bacteria may produce a powerful toxin, tetanospasmin, which actively impairs your motor neurons, nerves that control your muscles. The effect of the toxin on your motor neurons can cause muscle stiffness and spasms — the major signs of tetanus.

April 24, 2013