These bacteria live mostly in dirt. Gaining entry into the body through skin wounds, they produce an infection and a toxin that attacks nerves. The toxin causes sustained contraction or spasms of the muscles. These painful muscle spasms cause 'locking' of the jaw as well as problems with moving, breathing, eating, and drinking.
Tetanus can be fatal even when treated.
Tetanus is still seen in children that have not been vaccinated and newborns whose mothers lack immunity to tetanus. Tetanus also occurs in people in their 50s and 60s whose immunity has worn off. Vaccination with DTaP prevents tetanus.