Tetanus (cont.)

The tetanus toxin affects the site of interaction between the nerve and the muscle that it stimulates. This region is called the neuromuscular junction. The tetanus toxin amplifies the chemical signal from the nerve to the muscle, which causes the muscles to tighten up in a continuous ("tetanic" or "tonic") contraction or spasm. This results in either localized or generalized muscle spasms. Tetanus toxin can affect neonates to cause muscle spasms, inability to nurse, and seizures. This typically occurs within the first two weeks after birth and can be associated with poor sanitation methods in caring for the umbilical cord stump of the neonate. Of note, because of tetanus vaccination programs, there have only be a few cases of neonatal tetanus reported in the U.S. since 1990, and in each of these cases, the mothers were incompletely immunized. Worldwide, however, neonatal tetanus is still, unfortunately, common.

The incubation period between exposure to the bacteria in a contaminated wound and development of the initial symptoms of tetanus ranges from two days to two months, but it's commonly within 14 days of injury.

During a one- to seven-day period, progressive muscle spasms caused by the tetanus toxin in the immediate wound area may progress to involve the entire body in a set of continuous muscle contractions. Restlessness, headache, and irritability are common.

The tetanus neurotoxin causes the muscles to tighten up into a continuous ("tetanic" or "tonic") contraction or spasm. The jaw is "locked" by muscle spasms, giving the name "lockjaw" (also called "trismus"). Muscles throughout the body are affected, including the vital muscles necessary for normal breathing. When the breathing muscles lose their power, breathing becomes difficult or impossible and death can occur without life-support measures. Even with breathing support, infections of the airways within the lungs can lead to death.

Source: MedicineNet.com
http://www.medicinenet.com/tetanus/article.htm