What is tetanus?

Tetanus is a potentially serious bacterial infection. A person infected with tetanus can experience severe muscle spasms. Tetanus is also known by the name 'lockjaw' due to the characteristic jaw muscle spasm that it induces.

Tetanus can lead to death if left untreated, however the widespread use of an effective vaccine has made it a rare condition in countries with good healthcare systems. 

Causes

Tetanus is caused by the bacterium Clostridium tetani. C. tetani normally lives in soil, dirt and dust. It lives in some animal intestines and can make its way into the soil via their feces.

C. tetani enter the body via skin wounds, where it then replicates and releases a toxin. The toxin binds to the ends of nerve cells and triggers uncontrollable muscle spasms. The toxin can also be released as the bacteria die. This process can take a while. Thus, the time that can pass between the infection and the appearance of symptoms can vary greatly, ranging from a single day to several months. However, in most cases, symptoms appear within two weeks of infection. Generally, with a larger and more contaminated wound, symptoms will appear more quickly and the condition can be more serious.

Tetanus bacteria can infect the body through deep cuts and open wounds.Tetanus bacteria can infect the body through skin wounds. 

Risk factors

Risk factors for tetanus include:

  • No adequate immunization against tetanus;
  • Skin wounds, especially those involving dirt, rust or foreign bodies such as nails or splinters;
  • Deep cuts, bites, burns, penetrating wounds and frostbite;
  • Tattoos and body piercings;
  • Drug injections, and;
  • Infection of the umbilical stump in newborns of unimmunized mothers.

Even though obviously dirty wounds and serious open injuries are a higher risk for tetanus, seemingly minor wounds can also lead to tetanus. 

Types

Tetanus infections can be divided into four types:

Generalized tetanus

This comprises 80-90% of all tetanus cases. This form of tetanus has widespread effects on the skeletal muscles and often includes lockjaw. It can involve very painful intermittent muscle spasms. A range of other symptoms may appear including fever, heart rhythm disturbances and irritability.

Neonatal tetanus

This is a form of generalized tetanus that appears in newborn babies, especially when the mother is not immunized against tetanus and can not pass on her immunity in the short term. It is usually caused by the umbilical stump becoming contaminated after birth.

Neonatal tetanus is by far the most dangerous form of tetanus and leads to a large number of deaths, particularly in developing countries. In 2010, an estimated 58,000 newborn babies died of tetanus infection, which is a significant reduction from 20 years ago [1] .

Localised tetanus

This is an unusual form of tetanus, in which the signs and symptoms appear mainly near the infected area. It is usually milder than generalized tetanus, but can lead to generalized tetanus in some cases.

Cephalic tetanus

This is a rare form of tetanus. It usually appears after injuries to the head and face, or as a result of ear infections. Its incubation period is much shorter than that of other types - just 1-2 days. It can affect nerves in the face and cause the facial muscles to go limp. It can sometimes be confused with stroke, which can lead to a delay in diagnosis and treatment. Cephalic tetanus can lead to generalized tetanus.

Immunity

The body's ability to protect against an infection or toxin, generated by immunizations or exposure to previous infection.

1. Thwaites C.L. Beeching N.J. and Newton C.R. (2014) Maternal and neonatal tetanus. The Lancet 385:362-370.

Signs and symptoms

Signs of tetanus infection include:

Muscle spasms

The primary sign of tetanus infection is widespread stiffening of the muscles, especially in the areas near the infection site. Spasms can occur in all muscles including those of the limbs, neck, back and in the stomach (stomach cramps).

Jaw muscles can also be noticeably affected, causing a distinctive tightening that often makes it hard to open the mouth (lockjaw). A spasm of facial muscles can produce a facial expression that looks like a fixed smile. You may also experience difficulty swallowing.

These spasms can be triggered by very small stimuli - sounds, bright light, even touching the skin or hair. As the disease progresses, spasms of the vocal cords (laryngospasm) can occur, making it hard or impossible to breathe.

Additional symptoms

Other symptoms of a tetanus infection may include:

1. Thwaites C.L. Beeching N.J. and Newton C.R. (2014) Maternal and neonatal tetanus. The Lancet 385:362-370.

Methods for diagnosis

Your doctor will diagnose tetanus if you have recently been wounded and are showing the distinctive signs mentioned above. If there is doubt, your doctor may perform a spatula test - touching the back of your throat with a spatula. The normal reaction is a gag reflex. However, if you have established tetanus, you may automatically bite down on the spatula.

Laboratory tests do not always detect a tetanus infection.

1. Thwaites C.L. Beeching N.J. and Newton C.R. (2014) Maternal and neonatal tetanus. The Lancet 385:362-370.

Types of treatment

Tetanus is a medical emergency requiring hospitalization. Treatment for tetanus includes:

  • A thorough cleaning of the wound area, to eliminate any remaining tetanus bacteria. Many wounds will require surgical removal of dead or infected tissue containing the bacteria - this is called wound debridement;
  • Tetanus antitoxins, to target the tetanus toxin and lessen its effect;
  • Muscle sedatives and muscle relaxants to help reduce muscle stiffness and spasms;
  • Antibiotics - these may be of some use to help eliminate the tetanus bacteria and prevent further progression of the infection;
  • A ventilator to help with any breathing difficulties;
  • Rest in a quiet, dark room, in order to prevent any accidental triggering of painful spasms during recovery, and;
  • Vaccination - a previous tetanus infection does not provide immunity against further infection. Because the tetanus toxin is a very toxic substance, even a lethal dose of it is too small to induce an immune reaction. Therefore, a tetanus vaccination is required as part of the treatment.

Immunity

The body's ability to protect against an infection or toxin, generated by immunizations or exposure to previous infection.

1. Thwaites C.L. Beeching N.J. and Newton C.R. (2014) Maternal and neonatal tetanus. The Lancet 385:362-370.

Potential complications

Possible complications of tetanus include:

  • Breathing difficulties, due to contractions of the vocal cords, tongue and chest muscles;
  • Broken bones due to severe muscle spasms;
  • In infants, disability and brain damage;
  • Pneumonia;
  • Further infections, and;
  • Pulmonary embolism - a blood clot blocking the arteries of the lungs.

1. Thwaites C.L. Beeching N.J. and Newton C.R. (2014) Maternal and neonatal tetanus. The Lancet 385:362-370.

Prognosis

If caught and treated in time, a person infected with tetanus has a high chance of surviving. Infants and young children are most in danger from tetanus. Most deaths from tetanus occur in infants. Elderly people are also more susceptible, often because their immunity from vaccination has waned and no longer protects the body against tetanus.

Because the tetanus toxin attaches irreversibly to the nerve cell, a complete recovery needs to allow for new nerve cell ends to grow back. This can take time, sometimes many months in the case of serious, widespread infection and in some cases there can be permanent damage.

Immunity

The body's ability to protect against an infection or toxin, generated by immunizations or exposure to previous infection.

1. Thwaites C.L. Beeching N.J. and Newton C.R. (2014) Maternal and neonatal tetanus. The Lancet 385:362-370.

Prevention

There is an effective vaccine against tetanus and more than 84% of people globally receive tetanus vaccinations. In North America, Europe and Australia, the tetanus vaccination rate is nearly 100% [2] .

Vaccination.A vaccination is a very effective way of preventing a tetanus infection. 

Infants normally receive the tetanus vaccine (combined with other infant vaccines) as a series of three injections during their first year of life (at two, four and six months of age). Two booster doses are given in childhood - one at 18 months and again at four years of age. An additional dose is also recommended during the teenage years (between 10 and 17 years). These booster doses help your body maintain its immunity against a tetanus infection.

By the age of 50, the effect of these booster shots can wane. Adults who have reached this age and have not received a tetanus vaccination for more than 10 years may need another booster shot in order to remain protected against tetanus. This is particularly true for people who plan on visiting places where good medical treatment may not be easily accessible.

If wounded, you can reduce the risk of a tetanus infection by treating the wound quickly and effectively. A tetanus vaccine is often given as a precaution if you present for medical treatment with a tetanus-prone wound especially if it has been more than five years since your last known vaccination.

Vaccinations

The practice of administering a vaccine, a solution containing a microorganism (that causes a specific disease) in a dead or weakened state, or parts of it, for the purpose of inducing immunity in a person to that microorganism.

Vaccines

A preparation containing a microorganism (that causes a specific disease) in a dead or weakened state, or parts of it, for the purpose of inducing immunity in a person to that microorganism.

Immunity

The body's ability to protect against an infection or toxin, generated by immunizations or exposure to previous infection.

2. Global health observatory (GHO) data – Immunization. World Health Organization. Accessed 3 March 2015 from

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