Tetanus, sometimes called lockjaw, is a rare disease caused by bacteria known as Clostridium tetani. A toxin produced by the bacteria affects the function of the nerves and leads to severe muscle spasms in the abdomen, neck, stomach, and extremities. Tetanus can either be localized to one part of the body or generalized, with muscle spasms throughout the body. The disease has been called lockjaw since the muscle spasms in the face and neck can lead to the inability to open the mouth, and this is one of the most common symptoms of tetanus. Tetanus is a serious illness that is fatal in up to 30% of cases.
The bacteria that cause tetanus can be found in soil, manure, or dust. They infect humans by entering the body through cuts or puncture wounds, particularly when the wound area is dirty. Animal bites, burns, and non-sterile injection of drugs can also lead to infection with Clostridium tetani. The first symptoms of tetanus can appear any time from three days to weeks after infection, but the average time until symptom onset is eight days. Tetanus is not contagious, so you cannot acquire the disease from someone who has it.
In the United States, most people have had shots to prevent tetanus, so the disease is relatively rare. People who have never been immunized or haven't had a booster in the last 10 years are more likely to get tetanus. This includes people who recently moved to the U.S. from countries where tetanus shots are rare.
In developing countries of Africa, Asia, and South America, tetanus is far more common. The annual worldwide incidence is between 500,000-1 million cases. The majority of new cases worldwide are in neonates in third-world countries.
The disease can show four possible types:
Generalized tetanus can affect all skeletal muscles. It is the most common as well as the most severe form of the four types.
Local tetanus manifests with muscle spasms at or near the wound that has been infected with the bacteria.
Cephalic tetanus primarily affects one or several muscles in the face rapidly (in one to two days) after a head injury or ear infection. Trismus ("lockjaw") may occur. The disease can easily progress to generalized tetanus.
Neonatal tetanus is similar to generalized tetanus except that it affects a baby that is less than 1 month old (called a neonate). This condition is rare in developed countries.
You can prevent tetanus by getting all of your recommended immunizations (shots). There are three different combination immunizations that include a vaccine for tetanus.
DTaP (diphtheria, tetanus, and pertussis): DTaP is given in a series of 5 shots beginning at age 2 months and ending between ages 4 and 6 years.
Tdap (tetanus, diphtheria, and pertussis): Tdap is the first booster shot for tetanus and is recommended for children ages 11 or 12 who have completed the DTaP immunization series. It's also recommended for teens and adults who are due for a tetanus booster and have never had the Tdap shot.
Td (tetanus and diphtheria): Td is given as a booster shot every 10 years.
If you never had tetanus shots as a child, or if you're not sure if you had them, you'll need to get 3 tetanus shots in about a 1-year time span. After that, 1 booster shot every 10 years will work for you.
Get a tetanus shot as soon as possible if you have a dirty cut or wound and 5 or more years have passed since your last tetanus shot. Some people may need tetanus immunoglobulin (TIG) for a wound that is at high risk for tetanus. The immunoglobulin is usually only needed if you have not (or do not know whether you have) completed the tetanus shot series.
The bacteria that cause tetanus are called Clostridium tetani. They are usually found in dirt and soil, most often in areas with animal waste such as farms and ranches. These bacteria typically enter the body through a wound, cut, or splinter. They can also enter the body through an unclean injection, such as when a person injects a drug. Tetanus can also be a hazard to both the mother and newborn child (by means of the uterus after delivery and through the umbilical cord stump).
The bacteria grow best when they are not around oxygen. The deeper and narrower the wound, the less oxygen there is around it, so tetanus is more likely. For example, the bacteria can thrive in a puncture wound from a dirty nail. The dirtier the wound, the higher the risk of getting tetanus. But tetanus can also grow in a clean wound.
The potent toxin that is produced when the tetanus bacteria multiply is the major cause of harm in this disease.
In addition, certain factors are necessary for tetanus bacteria to proliferate in your body. These include:
Lack of immunization or inadequate immunization — failure to receive timely booster shots — against tetanus
A penetrating injury that results in tetanus spores being introduced to the wound site
The presence of other infective bacteria
Injured tissue
A foreign body, such as a nail or splinter
Swelling around the injury
Tetanus cases have developed from the following types of injuries:
Puncture wounds — including from splinters, body piercings, tattoos, injection drugs
Gunshot wounds
Compound fractures
Crush injuries
Burns
Surgical wounds
Ear infections
Dental infections
Animal bites
Infected foot ulcers in people with diabetes
Infected umbilical stumps in newborns born of inadequately immunized mothers
See your doctor to obtain a tetanus booster shot if you have a deep or dirty wound and you haven't had a booster shot within the past five years or aren't sure of your vaccination status. Or see your doctor about a tetanus booster for any wound — especially if it may have been contaminated with dirt, animal feces or manure — if you haven't had a booster shot within the past 10 years or aren't sure of your vaccination status.
Signs and symptoms of tetanus may appear anytime from a few days to several weeks after tetanus bacteria enter your body through a wound. The average incubation period is seven to eight days. The hallmark feature of tetanus is muscle rigidity and spasms.
In generalized tetanus, the initial complaints may include any of the following:
Irritability, muscle cramps, sore muscles, weakness, or difficulty swallowing are commonly seen.
Facial muscles are often affected first. Trismus or lockjaw is most common. This condition results from spasms of the jaw muscles that are responsible for chewing. A sardonic smile -- medically termed risus sardonicus -- is a characteristic feature that results from facial muscle spasms.
Muscle spasms are progressive and may include a characteristic arching of the back known as opisthotonus- Muscle spasms may be intense enough to cause bones to break and joints to dislocate.
Severe cases can involve spasms of the vocal cords or muscles involved in breathing. If this happens, death is likely, unless medical help (mechanical ventilation with a respirator) is readily available.
In cephalic tetanus, in addition to lockjaw, weakness of at least one other facial muscle occurs. In two-thirds of these cases, generalized tetanus will develop.
In localized tetanus, muscle spasms occur at or near the site of the injury. This condition can progress to generalized tetanus.
Neonatal tetanus is identical to generalized tetanus except that it affects the newborn infant. Neonates may be irritable and have poor sucking ability or difficulty swallowing.
Once tetanus toxin has bonded to your nerve endings it is impossible to remove. Complete recovery from a tetanus infection requires the growth of new nerve endings and can take up to several months.
Complications of tetanus infection may include:
Disability. Treatment for tetanus typically involves the use of powerful sedatives to control muscle spasms. Prolonged immobility due to the use of these drugs can lead to permanent disability. In infants, tetanus infections may cause lasting brain damage, ranging from minor mental deficits to cerebral palsy.
Death. Severe tetanus-induced (tetanic) muscle spasms can interfere with your breathing, causing periods in which you can't breathe at all. Respiratory failure is the most common cause of death. Lack of oxygen may also induce cardiac arrest and death. Pneumonia is another cause of death.
There is no lab test for tetanus. A doctor can usually diagnose tetanus after asking questions about your symptoms and past health and doing a physical exam. Because other problems can cause muscle spasms like tetanus, your doctor will do tests to make sure your symptoms are not caused by something else.
Your doctor will do tests to decide how to treat your symptoms. For example, he or she may order a blood test (arterial blood gases) to see how well you are breathing.
If you are infected with tetanus, you will need to stay in a hospital so you can get medicines and fluids to control muscle spasms and pain. You also may need treatment to help you breathe. Your doctor will fully clean any wound or cut to remove bacteria. Cleaning the affected area stops bacteria from making toxin. Treatment also includes:
Antibiotics. These medicines kill bacteria.
Tetanus immunoglobulin (TIG). This is a protein that helps your body's immune system find and destroy bacteria. TIG boosts your immunity while your body fights the infection.
Medicines to decrease muscle spasms. You also may be treated in an intensive care unit (ICU) with medicines that paralyze your muscles for a while until your body begins to recover. In this case, you will need treatment to help with breathing and other body functions.
After you've had tetanus, you are not immune to the disease. You could get infected again. So keep getting routine tetanus shots after you get better.
The tetanus vaccine is a toxoid, meaning that it protects against the toxin produced by the bacteria. Developed in the 1920s, tetanus vaccination became routinely used as a part of childhood immunizations in the U.S. after World War II, and it is considered to be essentially 100% effective in preventing tetanus. Tetanus immunization is almost always administered to children in the form of the DTaP vaccine, which also protects against diphtheria and pertussis. Tetanus toxoid can also be given in combination with diphtheria vaccine alone in both adult (Td) and pediatric (DT) formulations.
Infants are commonly given the DTaP vaccine in a schedule of four doses at 2, 4, 6, and 15-18 months of age. Another dose is administered at 4 to 6 years of age. Because the levels of antitoxin in the body gradually fall over time, booster vaccinations with the combined diphtheria-tetanus toxoid (Td) are recommended every 10 years. Td is a tetanus-diphtheria vaccine given to adolescents and adults as a booster shot every 10 years or after a presumed exposure in some cases, while Tdap is a similar vaccine that also contains protection against pertussis. A single dose of Tdap is recommended for children at the 11- to 12-year-old checkup.
If it has been more than 10 years since your last tetanus booster, contact your doctor to bring your immunizations up to date. A booster vaccination is also recommended if you sustain a deep, contaminated wound and more than five years have passed since the last dose, since protective antibody levels may fall after five years in some people. You should also receive a series of three tetanus immunizations if you did not receive the childhood vaccine.
Serious adverse reactions from the tetanus shot are very rare. Mild reactions include localized swelling, tenderness, and redness at the injection site that generally persist for one to two days after vaccination.