Tetanus is a serious nervous system disease caused by contamination of wounds with a toxin‑producing bacterium that causes muscle contractions, particularly of your jaw and neck muscles. It is also known as lockjaw.
There is no cure for it. Severe complications can be life‑threatening.
Widespread use of tetanus vaccines has resulted in it becoming rare in many parts of the world but it remains a threat for those who have not been vaccinated or are not up to date with their vaccinations.
Symptoms
The most common symptoms of tetanus are muscle rigidity and spasms. The average incubation period is seven to 10 days but it can range from three to 21 days. The shorter the incubation period, the more severe the symptoms usually are.
Generalised tetanus symptoms begin gradually and progressively become worse, usually starting at the jaw and progressing downwards.
Initial symptoms may include irritability, muscle cramps, sore muscles, painful muscle spasms, weakness or difficulty swallowing. Your facial muscles are often the first to be affected.
The most common symptom is 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.
As tetanus progresses it may result in repeated painful seizure-like spasms that last several minutes. The neck and back may arch, a condition known as opisthotonus. The legs may become rigid and the arms be drawn up to the body with the fists clenched. Spasms may be severe enough to result in broken bones or joint dislocation.
Severe cases can involve spasms of the vocal cords or muscles involved in breathing. If this happens, death is a real possibility unless medical help such as mechanical ventilation with a respirator is readily available.
Localised tetanus is a rare form of tetanus which results in spasms near the site of a wound. It is less severe but can progress to generalised tetanus.
Cephalic tetanus is another rare form of tetanus that can progress to generalised tetanus. It results from a head wound. It is characterised by weakened face muscles and spasms of the jaw muscles.
Causes
Tetanus is caused by the bacterium Clostridium tetani, a rod-shaped bacterium that is found in soil, animal waste or dust usually in a dormant form, which may become active when it comes in contact with a wound.
The bacteria are found in two forms, as a spore or as a vegetative cell that can multiply. They can survive in dormant form for many years and are resistant to temperature extremes.
Contamination of a wound with tetanus spores is common. Tetanus, however, can only occur when the spores germinate and become active bacterial cells that release a toxin called tetanospasmin, a toxin that impairs the nerves in the body that control muscles. Wounds provide good conditions for this to happen.
Most cases of tetanus result from a puncture wound, a cut or a scrape. Other tetanus-prone injuries include frostbite, surgery, crash wound, burns, abscesses, childbirth, intravenous (IV) drug use and wounds with dead tissue.
Tetanus may develop in people who are not immunised against it or in people who have failed to maintain adequate immunity with active booster doses of vaccine.
Death from tetanus is often caused by a blocked airway during spasms or damage to the nerves that regulate breathing, heart rate or other organ functions.
When to see a doctor
Tetanus is a life-threatening disease. If you have signs or symptoms of tetanus, seek emergency care. If you have a simple, clean wound and you have had a tetanus shot within 10 years, you can probably care for your wound at home.
Seek professional medical care if your last tetanus shot was over 10 years ago or you are unsure when you last had it and have a puncture wound, a foreign object in your wound, an animal bite or a deep cut.
You should also seek urgent professional help if your wound is contaminated with dirt, soil, faeces, rust or saliva, or you have any doubt about whether you have cleaned a wound sufficiently after such exposure.
Contaminated wounds require a vaccination booster if it has been five or more years since your last tetanus shot.
Treatment
The medical treatment for tetanus has two aims. The first is to limit growth and eventually kill the infecting bacterium and thus eliminate toxin production. The second aim is to neutralise any toxin that is formed.
If the toxin has already affected you, the two aims are still important but supportive measures will be needed. These measures include taking antibiotics to kill the bacteria and having a tetanus booster shot.
Wound cleansing to remove any obvious bacteria abscesses or foreign bodies helps with treatment.
Other supportive treatment measures may include pain medicine, sedatives such as diazepam to control muscle spasms and muscle relaxants and ventilator support to help with breathing in the event of spasms of the vocal cords or the respiratory muscles.
Prevention
Most adult tetanus infections can be prevented by active immunisation with tetanus toxoid. Neonatal cases can be prevented by good hygiene and a careful, sterile technique used to sever the umbilical cord. Active immunisations can be given to the baby after two months.
There are two main vaccines recommended. For children, diphtheria tetanus and acellular pertussis combination (DTaP) vaccine is used. For non-immunised adults and booster shots, tetanus and reduced amounts of diphtheria and acellular pertussis combination (Tdap) vaccine is recommended.
The initial series for non-immunised adults involves three doses of Tdap. The first and second doses are given four to eight weeks apart. The third dose is given six months after the second. Booster doses are required every 10 years after that.
In children, the immunisation schedule calls for a shot frequency of five doses of DTaP. One dose is given at two, four, six and 15-18 months of age. This DTaP series is completed with a final dose when the child is between 4-6 years of age.
Additional boosters with Tdap are given every 10 years after the final DTaP dose. Children who do not react well to DTaP can be given Tdap doses.
Expecting mothers are recommended to have a booster during the third trimester of the pregnancy, regardless of their vaccination schedule.
You should consult your doctor to review your vaccination status on a regular basis to see whether you are current on your vaccination schedule, especially if you have any international travel plans.
