Tetanus results from a toxin produced by the anaerobic bacteria Clostridium tetani. The toxin makes muscles contract involuntarily and become rigid.
Tetanus usually develops after a wound or an injury that breaks the skin becomes contaminated.
Diagnosis is based on symptoms.
Treatment includes giving tetanus immune globulin to neutralize the toxin and treating symptoms until they resolve.
Vaccination and appropriate wound care can prevent tetanus.
(See also Overview of Clostridial Infections.)
Clostridium tetani do not require oxygen to live. That is, they are anaerobes.
Tetanus is rare in the United States but is common in areas of the world where immunization coverage is low. It can occur in people of all ages, even infants.
Clostridium tetani is present in soil and animal feces and can live there for years. Tetanus bacteria may enter the body through
Wounds contaminated with soil or feces (especially if the wound is not adequately cleaned)
Skin punctures by contaminated needles (such as those used to inject illegal drugs or to tattoo or do body piercing)
Sometimes the injury is so small that people do not even go to a doctor. Injuries that involve a foreign body (such as a splinter, dirt, or bullet fragments) and dead tissue (such as burns, frostbite, gangrene, or crush injuries) are more likely to cause tetanus.
Occasionally, tetanus can develop when the uterus is damaged during an induced abortion or childbirth. Soil contamination of the stump of the umbilical cord, which may occur in parts of the world with inadequate sanitation, can cause tetanus in newborns.
Tetanus bacteria produce spores. Spores are an inactive (dormant) form of bacteria. Spores enable bacteria to survive when environmental conditions are difficult. When conditions are favorable, spores germinate into active bacteria.
Clostridium tetani bacteria produce tetanus toxins. These toxins travel throughout the body and prevent certain nerves from sending signals to other nerves. As a result, muscles contract involuntarily, causing stiffness and painful muscle spasms.
Vaccination during childhood plus booster doses every 10 years during adulthood can prevent tetanus. Thus, tetanus occurs mainly in people who have not been vaccinated or have not kept their vaccinations up to date. In the United States, the risk of developing tetanus is high for the following:
People who have burns or surgical wounds or who inject drugs
People over 60 because immunity decreases over time
People who were never given the primary series of tetanus vaccine, which is part of routine childhood vaccination
People who have diabetes or who take medications that weaken their immune system may be at risk of developing tetanus.
Symptoms of Tetanus
Tetanus symptoms usually begin about 5 to 10 days after the injury but may begin up to about 50 days later.
Muscle spasms are the characteristic feature of tetanus. Muscles contract involuntarily (spasm) and become rigid. Tetanus is often called "lockjaw" because the spasms cause the jaw and neck muscles to tighten and lock, making it hard to open the mouth or swallow. The spasms also affect the shoulder, face, abdomen, and limbs. Such spasms may interfere with breathing, sometimes so much that people turn blue. The face may be frozen in a smile with the eyebrows raised. Back muscles contract, making the back, neck, and legs arch backward. Spasms of sphincter muscles can lead to constipation and difficulty urinating. Slight disturbances—such as noise, a draft, or the bed being jarred—can trigger painful muscle spasms throughout the body.
Rarely, muscle spasms may be limited to muscle groups near the wound. Such localized tetanus may persist for weeks.
Other symptoms occur because tetanus affects the nervous system, including the part that regulates internal body processes, such as how fast the heart beats. People with tetanus may have a rapid heartbeat and a slight fever. They may sweat profusely. Blood pressure may go up and down. People may inhale (aspirate) the contents of their mouth into their lungs, resulting in pneumonia.
People may be restless and irritable. However, even when the illness is severe, people usually remain fully conscious.
In newborns, tetanus usually affects the whole body and is frequently fatal. In the first 2 weeks of life, the infant has spasms and feeds poorly.
Children who survive may be deaf.
Did You Know...
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Diagnosis of Tetanus
A doctor's evaluation
A doctor suspects tetanus when certain muscles (commonly, jaw and back muscles) become rigid or spasms occur, particularly in people who have a wound.
The bacteria can sometimes be grown (cultured) from a sample taken from the wound. However, culture results sometimes indicate tetanus when it is not present (a false-positive result), and tetanus may be present even if no bacteria are detected (a false-negative result). Thus, doctors do not rely on culture to diagnose tetanus.
Treatment of Tetanus
Wound cleaning and removal of dead tissue and foreign material
Human tetanus immune globulin (antitoxin)
Treatment of symptoms, sometimes including a mechanical ventilator
Antibiotics
People with tetanus are admitted to an intensive care unit. The room is kept quiet to prevent disturbances that could trigger muscle spasms. Wounds are cleaned thoroughly, and dead tissue and foreign material are removed.
A dose of human tetanus immune globulin (antitoxin) is usually injected into a muscle to neutralize the toxins. If the antitoxin is unavailable, doctors may give people immune globulin, which contains many different antibodies, including those that protect against tetanus.
Antibiotics are given intravenously to kill the bacteria in the wound and thus stop the production of toxin. However, antibiotics have no effect on toxin that has already been produced. Such toxin continues to cause muscle spasms.
People do not develop immunity to tetanus once they have had tetanus. That is, they can get tetanus again. Therefore, after people who have tetanus recover from the infection, they are given tetanus vaccine unless their vaccinations are known to be up to date.
Management of symptoms
If muscle rigidity interferes with breathing, a tube may be placed in the windpipe (called endotracheal intubation), and the person is given a medication to paralyze the muscles and thus stop the spasms. Then the tube is attached to a mechanical ventilator that breathes for the person.
beta-blocker, or other medications.
If swallowing is difficult, nutrition and fluids are given intravenously or, less often, through a tube inserted through the nose and into the stomach.
If constipation develops, which is common, stool softeners are given, and a tube may be inserted into the rectum to help manage gas production.
Prognosis for Tetanus
With treatment, most people recover.
People who inject drugs, the very young, and the very old are more likely to die of tetanus. The outlook is worse if symptoms develop quickly and progress rapidly or if treatment is delayed.
Prevention of Tetanus
Preventing tetanus is far better than treating tetanus.
Vaccination
The tetanus vaccine stimulates the body to produce antibodies that neutralize the toxin. But it may take several weeks after vaccination for these antibodies to develop. (Antibodies are proteins produced by the immune system to help defend the body against an infection.)
There is no separate vaccine just for tetanus. The diphtheria/tetanus toxoids/pertussis vaccine (DTaP vaccine) is a combination vaccine that protects against diphtheria, tetanus, and pertussis (whooping cough). The DTaP vaccine is one of the routine immunizations of childhood.
Five doses of DTaP vaccine are routinely recommended as a primary series for children. They are given at 2 months, 4 months, 6 months, 15 to 18 months, and 4 to 6 years of age.
DTaP is followed by one lifetime booster dose of tetanus, diphtheria, and acellular pertussis (Tdap) vaccine given at age 11 to 12 years and to people 13 years or over who have never received Tdap or who are unsure about whether they received it. A booster dose containing only tetanus and diphtheria (Td) or Tdap is given to all people every 10 years after that.
Pregnant women are given a Tdap booster during each pregnancy (preferably at 27 to 36 weeks gestation). This strategy prevents women and newborns from getting tetanus. When pregnant women are vaccinated, antibodies to tetanus are transferred from the mother to the fetus during pregnancy, and the newborn has antibodies to tetanus at birth.
Tetanus rarely develops in people who have completed a primary series of a tetanus vaccine and had booster vaccinations every 10 years, as recommended.
After a wound
When people are injured, they can help prevent tetanus by promptly and thoroughly cleaning wounds.
People who have been immunized against tetanus in the past and have a wound may be given one dose of tetanus vaccine to prevent tetanus from developing if they have not had a dose of vaccine in the last 10 years (or in the last 5 years if the wound is deep or dirty).
If people have not been previously vaccinated, they are given a dose of the vaccine immediately and two more doses one and two months later. In addition, because the vaccine takes weeks to be effective, human tetanus immune globulin is sometimes given in addition when a wound is deep or particularly dirty. This immune globulin is obtained from human donors who have high levels of antibodies to the tetanus toxin. These antibodies neutralize the toxin immediately.
More Information
The following English-language resource may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
Centers for Disease Control and Prevention: Tetanus: A resource providing general information about causes, treatment, and vaccination of tetanus
