What is Tetanus?
Tetanus is the result of an infection that affects the muscles and nerves, usually
due to a contaminated wound. Tetanus is a serious bacterial infection that leads to stiffness of your jaw and other muscles. It can cause severe muscle spasms, make breathing difficult and, ultimately, threaten your life.
A cut, puncture wound, bite or other wound, even if minor, can lead to a tetanus infection in someone without immunity to the infection. Spores of the tetanus bacteria, Clostridium tetani, usually are found in the soil but can occur virtually anywhere. If they enter a wound beyond the reach of oxygen, they produce a toxin that interferes with the nerves controlling your muscles.
Treatment is available, but the process is lengthy and not uniformly effective. Tetanus may be fatal despite treatment. A small number of those result in death. The number of cases and of resulting deaths is far higher in developing countries. The best defense against tetanus is prevention.
Where do tetanus bacteria grow in the body?
Contaminated wounds are the sites where tetanus bacteria multiply. Deep wounds or those with devitalized (dead) tissue are particularly prone to tetanus infection.Puncture wounds such as those caused by nails, splinters, or insect bites are favorite locations of entry for the bacteria. The bacteria can also be introduced through burns, any break in the skin, and injection-drug sites. 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 potent toxin that is produced when the tetanus bacteria multiply is the major cause of harm in this disease.
How does the tetanus toxin cause damage to the body?
The tetanus toxin affects the site of interaction between the nerve and the muscle that it stimulates. This region is called the neuromuscular junction. The tetanus toxin amplifies the chemical signal from the nerve to the muscle, which causes the muscles to tighten up in a continuous ("tetanic" or "tonic") contraction or spasm. This results in either localized or generalized muscle spasms. Tetanus toxin can affect neonates to cause muscle spasms, inability to nurse, and seizures. This typically occurs within the first two weeks after birth and can be associated with poor sanitation methods in caring for the umbilical cord stump of the neonate. Of note, because of tetanus vaccination programs, only three cases of neonatal tetanus have been reported since 1990, and in each of these cases, the mothers were incompletely immunized.What is the incubation period for tetanus?
The incubation period between exposure to the bacteria in a contaminated wound and development of the initial symptoms of tetanus ranges from two days to two months, but it's commonly within 14 days of injury.Causes
The bacteria that cause tetanus, Clostridium tetani, are found in soil, dust and animal feces. When they enter a deep flesh wound, spores of the bacteria may produce a powerful toxin, tetanospasmin, which actively impairs your motor neurons, nerves that control your muscles. The effect of the toxin on your nerves can cause muscle stiffness and spasms — the major signs of tetanus.
Signs and symptoms
Signs and symptoms of tetanus may include:
Stiffness of the jaw, neck and other muscles
Irritability
Spasms of your jaw and neck muscles
Painful muscle spasms
Some people may experience only pain and tingling at the wound site and some spasms in nearby muscles. But as the toxin spreads to nerves supplying muscles, most people have stiffness of the jaw and neck, difficulty swallowing and irritability. Facial and jaw muscles are most often affected by strong spasms. This is why tetanus is commonly referred to as lockjaw.
Spasms of your jaw or facial muscles progress to spasms and rigidity of your neck, abdominal and back muscles. Finally, severe spasms can affect respiratory muscles and make it difficult for you to breathe. You're usually awake and alert throughout the disease.
Treatment
Tetanus may be mild and its effects limited to one part of your body if you have a partial immunity to tetanus. Recovery can occur without treatment. However, mild forms of tetanus aren't common. In most cases of tetanus, the illness is severe and widespread, and there's a risk of death despite treatment.
Treatment may include use of an antibody, tetanus immune globulin (TIG), and tetanus antitoxin. However, the antitoxin can only neutralize toxin that hasn't yet combined with nerve tissue. Your doctor may also give you antibiotics, either orally or by injection, to fight tetanus bacteria.
Tetanus infection usually requires a long period of treatment in an intensive care setting. Drugs will be used to sedate you and to paralyze your muscles so that breathing must be supported temporarily by a ventilator. In some cases, you may need to use a ventilator for 2 to 3 weeks.
Death may result from constriction of airways, pneumonia or instability in the autonomic nervous system. The autonomic nervous system is the part of your nervous system that controls your heart muscles, other involuntary muscles and glands. People who recover from tetanus sometimes have lasting effects, including defects in the nervous system and psychological problems that may require psychotherapy.
