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, including 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 can also spread to the spine and attach to the ends of nerves of the spinal cord and at neuromuscular junctions (the locations where nerves meet muscles). The toxin blocks the release of a neuro-transmitter (NOO-ro-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 * .
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.
Tetanus is not spread from person to person. Bacterial spores must enter a wound for the infection to spread.
The diagnosis is made based on the presence of symptoms and the patient's history (for example, getting a wound by stepping on a soil-contaminated nail). Laboratory tests are not useful in determining whether a patient has tetanus. A culture * of the wound can be done, but these cultures generally do not show the bacteria.
Typically, tetanus infection is treated in a hospital. Treatment begins with giving the patient tetanus immune globulin * to control or reverse the effects of toxin that has not yet attached itself to nerve endings. Penicillin or other antibiotics may also be given to kill the bacteria. Cleaning the wound and removing dead tissue, in some cases by surgery, is important in ridding the body of invading bacteria. Muscle spasms can be treated with muscle relaxants. Respiratory system * support, provided by a respirator * , may be necessary to help maintain breathing if the respiratory muscles have been affected.
Symptoms may last three to four weeks, although complete recovery can take several months. Tetanus can be mild, but in most cases, the illness is severe, and death may occur even after treatment has begun. Tetanus usually requires a long stay in the intensive care unit of the hospital.
Complications of the illness include spasms of the vocal cords and the muscles that control breathing, which can lead to difficulty breathing; fractures in the long bones or the spine from severe muscle spasms and convulsions; high blood pressure; abnormal heart rhythm; secondary infections, such as sepsis * and pneumonia (inflammation of the lung); a blood clot * in the lungs; and death. In the United States, 10 to 20 percent of reported tetanus cases are fatal. Unvaccinated children and the elderly are at greater risk of dying if they become infected with tetanus bacteria.
Immunization is the best means of preventing tetanus. The vaccination is usually given in combination with other vaccines: the DTaP (diphtheria * /tetanus/acellular/pertussis * ) form for children and the Td (tetanus/diphtheria) form for adults. A series of shots is required to develop immunity to tetanus toxin, followed by booster shots every 10 years. In some cases of unclean wounds, a booster is given after the injury to help prevent tetanus.
See also Bacterial Infections • Skin and Soft Tissue Infections • Vaccines and Immunization
Hinfey, Patrick B. “Tetanus.” Medscape, June 17, 2015. http://emedicine.medscape.com/article/229594-overview (accessed November 17, 2015).
Mitchell, Duane A., Kristen A. Batich, Michael D. Gunn, et al. “Tetanus Toxoid and CCL3 Improve Dendritic Cell Vaccines in Mice and Glioblastoma Patients.” Nature Journal 519 (2015): 366–69. http://www.nature.com/nature/journal/vaop/ncurrent/full/nature14320.html (accessed November 17, 2015).
MedlinePlus. “Tetanus.” U.S. National Library of Medicine, National Institutes of Health. https://www.nlm.nih.gov/medlineplus/tetanus . html (accessed November 17, 2015).
New York State Department of Health. “Tetanus (Lockjaw).” https://www.health.ny.gov/diseases/communicable/tetanus/fact_sheet.htm (accessed November 17, 2015).
Centers for Disease Control and Prevention. 1600 Clifton Rd., Atlanta, GA 30329-4027. Toll-free: 888-674-6854. Website: http://www.cdc.gov (accessed November 17, 2015).
World Health Organization. 525 Twenty-Third St. NW, Washington, DC 20037. Telephone: 202-974-3000. Website: http://www.who.int/en/ (accessed November 17, 2015).
* central nervous system (SEN-trul NER-vus SIS-tem) is the part of the nervous system that includes the brain and spinal cord.
* convulsions (kon-VUL-shuns), also called seizures, are involuntary muscle contractions caused by electrical discharges within the brain and are usually accompanied by changes in consciousness.
* spores are a temporarily inactive form of a germ enclosed in a protective shell.
* spasms (SPAH-zumz) are involuntary muscular tightening or contractions.
* neonatal (ne-o-NAY-tal) means pertaining to the first 4 weeks after birth.
* umbilical cord (um-BIH-lih-kul) is the flexible cord that connects a baby to the placenta, the organ that unites the unborn child to the mother's uterus, the organ in which the baby develops.
* sterilize (STAIR-uh-lyze) is to eliminate all live bacteria or microorganisms from something, usually through the use of heat, pressure, chemicals, or other antimicrobial agents.
* vaccination (vak-sih-NAY-shun), also called immunization, is giving, usually by an injection, a preparation of killed or weakened germs, or a part of a germ or product it produces, to prevent or lessen the severity of the disease caused by that germ.
* intravenous (in-tra-VEE-nus), or IV, means within or through a vein. For example, medications, fluid, or other substances can be given through a needle or soft tube inserted through the skin's surface directly into a vein.
* abdominal (ab-DAH-mih-nul) refers to the area of the body below the ribs and above the hips that contains the stomach, intestines, and other organs.
* culture (KUL-chur) is a test in which a sample of fluid or tissue from the body is placed in a dish containing material that supports the growth of certain organisms. Typically, within days the organisms will grow and can be identified.
* immune globulin (ih-MYOON GLAH-byoo-lin), also called gamma globulin, is the protein material that contains antibodies.
* respiratory system, or respiratory tract, includes the nose, mouth, throat, and lungs. It is the pathway through which air and gases are transported down into the lungs and back out of the body.
* respirator is a machine that helps people breathe when they are unable to breathe adequately on their own.
* sepsis is a potentially serious spreading of infection, usually bacterial, through the bloodstream and body.
* blood clot is a thickening of the blood into a jelly-like substance that helps stop bleeding. Clotting of the blood within a blood vessel can lead to blockage of blood flow.
* diphtheria (dif-THEER-e-uh) is an infection of the lining of the upper respiratory tract (the nose and throat). It is a serious disease that can cause breathing difficulty and other complications, including death.
* pertussis (per-TUH-sis) is a bacterial infection of the respiratory tract that causes severe coughing.