Tetanus (Lockjaw)

Tetanus (TET-nus) is a serious bacterial infection that affects the body's central nervous system. Tetanus, also known as lockjaw, can lead to muscle rigidity, convulsions, and death.

What Is Tetanus?

Tetanus is a disease caused by infection with Clostridium tetani (klos-TRIH-dee-um teh-TAH-nye) bacteria, which are found all over the world in soil, dust, and some animal feces (FEE-seez, or bowel movements) and even on human skin. The bacteria can enter the body through any type of wound, such as a scratch or deep cut. Infection begins after bacterial spores have moved deep within the body and become active. Clostridium tetani bacteria are anaerobic (ah-nuh-RO-bik), meaning that they grow best in places with very little oxygen-so the deeper they travel into the body, the better their chances of survival.

Once tetanus spores become active, the bacteria begin producing a toxin (a poisonous substance) called tetanospasmin (teh-tuh-no-SPAZ_min), which attaches to the nerves around the area of the wound. The tetanus toxin also can spread to the spine and attach to the ends of nerves of the spinal cord and at neuromuscular junctions (where nerves meet muscles). The toxin blocks the release of a neurotransmitter (nur-o-trans-MIH-ter), a chemical that carries a signal from nerves to other nerves or muscles. This block affects the messages that the muscles receive, resulting in severe muscle spasms that can be powerful enough to tear muscles apart.

There are three types of tetanus infection. Local tetanus is limited to the area of the wound; cephalic (seh-FAH-lik) tetanus is an uncommon form that affects the nerves of the face after a head injury or, rarely, a long-lasting ear infection; and generalized tetanus affects much of the body and accounts for the majority of tetanus cases. Neonatal tetanus is a generalized form of the infection that occurs in newborns. It is caused by bacteria contaminating the stump of the umbilical cord, particularly if the cord has been cut with an instrument that has not been sterilized.

How Common Is It?

Tetanus occurs around the world but is found frequently in densely populated areas that have hot, damp climates. The disease is rare in the United States primarily because of vaccination. Nearly all reported cases of tetanus occur in people who have never been vaccinated or who have not had a booster shot in the previous 10 years. Neonatal tetanus infection is rare in developed countries because of improved surgical techniques, but there are hundreds of thousands of deaths from tetanus annually worldwide, mostly in developing countries. Intravenous* drug abusers, such as people who inject heroin, are at a higher risk of contracting the disease.

Is Tetanus Contagious?

Tetanus is not spread from person to person. Bacterial spores must enter a wound for the infection to spread.

What Are the Signs and Symptoms of Infection?

Symptoms of tetanus appear from 3 to 21 days or longer after infection, but usually they develop within seven days. In about 50 percent of generalized cases of tetanus, the first sign is trismus, or stiffness in the jaw muscles (also known as lockjaw), followed by a stiff neck, shoulder, or back; trouble swallowing; and fever. Spasms can soon spread to the abdominal muscles, upper arms, and thighs. Other symptoms include sweating, high blood pressure, and periods of rapid hearrbeat. The closer the infection is to the central nervous system, the sooner the symptoms appear. The carlier the symptoms begin to appear, the greater the risk of death.