Skip to main content Skip to Search Box

Definition: tetanus from Merriam-Webster's Collegiate(R) Dictionary

(14c) 1 a : an acute infectious disease characterized by tonic spasm of voluntary muscles esp. of the jaw and caused by an exotoxin of a bacterium (Clostridium tetani) which is usu. introduced through a wound compare lockjaw b : the bacterium that causes tetanus 2 : prolonged contraction of a muscle resulting from rapidly repeated motor impulses

Summary Article: Tetanus
From Encyclopedia of Global Health

Tetanus is a bacterial infection that affects the nervous system. It is estimated that there are one million cases of tetanus per year worldwide, the majority occurring in developing countries. Neonatal tetanus is particularly dangerous, often caused by non-sterile delivery methods and incomplete vaccination. According to the WHO, over 200,000 cases/year of neonatal deaths from tetanus occurred in the year 2000. In the U.S. however, with wide-spread vaccination, only 50 cases of the disease occur per year.


Clostridium tetani, the organism that causes a tetanus infection, is an anaerobic, sport forming, gram-positive bacterium. Its spores are ubiquitous in soil, and are also found in dust and animal feces.

Infection can occur through any open wound: cuts, scrapes, needle injection sites, the umbilical cord, insect bites. The infection rate is higher if the wound is contaminated with soil or caused by wood splinters or dirty, rusty metal. Neonatal tetanus is most often caused by the use of dirty instruments (scissors, clamps, etc.) to cut the umbilical cord.

After the organism enters an open wound, bacterial spores germinate in an anaerobic (low oxygen) environment and release the neurotoxin tetanospasmin. This toxin acts on the myoneuronal (muscle-nerve) junction to inhibit the ability of muscles to relax.


Symptoms of a tetanus infection usually arise one to two weeks after exposure. The tetanus toxin prevents muscles from relaxing, causing a condition known as “spastic paralysis.” In other words, the muscles are locked in the contracted position, leading to a stiff jaw, stiff neck, and the contraction of facial muscles resulting in a sneering expression known as risus caninus.

In newborn children, if tetanus is acquired during delivery, symptoms arise by the end of the first month of life. Symptoms include stiff muscles, fever, and poor feeding.

Muscle spasms, also known as “tetany” are associated with a more advanced stage of the disease and a poor prognosis.


These muscle spasms can be violent enough to cause spinal fractures. Tetanus has also been associated with abnormal heart rhythms. In adults, with proper treatment, the overall prognosis is good. For children however, prognosis is poor and often results in death. The overall mortality rate of tetanus is 10 percent.

A history of past tetanus infection does not make a patient immune to another infection, so these patients must also be vaccinated.


Tetanus infections are treated with antibiotics (penicillin or metronidazole) and tetanus antitoxin. The antitoxin is an immunoglobulin that neutralizes tetanospasmin. In severe cases, patients may be unable to breathe independently and they must be place on mechanical ventilation.

The disease can be prevented using a vaccine and by hygienic and sterile wound care and childbirth. In the US, the vaccine is given as the combination vaccine DTaP at 2, 4, 6, and 15 months, and 5 years of age. A booster is then given every 10 years, or after an injury if the last booster was more than 5 years prior. Unvaccinated adults get a three injection series over seven months.

A history of past tetanus infection does not make a patient immune to another infection, so these patients must also be vaccinated. Pregnant women should be vaccinated to pass on some immunity to the newborn child, this can be done while the woman is pregnant. Other countries use different vaccine combinations, including formulations with the hepatitis A and Haemophilus influenzae B (HiB) vaccines.

Practically speaking, tetanus is prevented by thoroughly cleaning wounds, giving a booster vaccine to individuals with an unknown vaccination history, and the use of sterile instruments during childbirth.

The WHO, UNICEF, and the UNFPA are following these guidelines to reduce neonatal tetanus in developing countries. Their strategies include increased vaccination of pregnant women, vaccinating all women of child-bearing age in endemic areas, and promoting clean delivery methods.

  • Botulism; World Health Organization (WHO).

  • Center for Disease Control and Prevention,
  • Daniel J. Dire, “Tetanus,” (cited December 2005).
  • Elias Abrutyn, “Tetanus,” in Harrison’s Principles of Internal Medicine, 15th ed. (McGraw-Hill, 2001).
  • World Health Organization, “Tetanus,” (cited May 2006).
  • Amit Chandra, MD, M.Sc.
    NY Hospital Queens
    Copyright © 2008 by SAGE Publications, Inc.

    Related Articles

    Full text Article Eliminate Project, The
    The SAGE Encyclopedia of World Poverty

    Launched in 2010, the Eliminate Project is a collaboration between Kiwanis International and United Nations Children's Fund (UNICEF) with the sole p

    Full text Article Tetanus
    Encyclopedia of the Neurological Sciences

    This article is a revision of the previous edition article by Bradley A Cole, volume 4, pp 498–499, © 2003, Elsevier Inc. Abstract Tetanus occurs

    Full text Article adsorbed tetanus vaccine
    The Royal Society of Medicine: Medicines

    Adsorbed tetanus vaccine (Tet/Vac/Ads) is a vaccine used for immunization against tetanus and is adsorbed onto a mineral carrier. This...

    See more from Credo