What is tetanus?
Tetanus is an acute, often fatal, infectious disease caused by the bacterium Clostridium tetani and is characterized by painful involuntary muscle contractions.
It’s commonly known as lockjaw, due to the rigidity and tightness of the jaw as a result of involuntary muscle contraction when one suffers from the disease. Muscle spasms usually begin at the jaw, moving to the neck, then gradually to the rest of the body.
The muscle spasms may be extreme, to the extent of breaking bones and causing breathing problems that can lead to death. The manifestation of the disease usually ranges from 3 to 21 days, usually about 8 days after being infected with the bacteria.
How common is tetanus?
In developed countries, due to widespread immunization and careful wound care, the total annual number of tetanus cases is about 40-50 on average since 1995.
In developing regions of Africa, Asia, and South America, tetanus is more common. The annual worldwide incidence is between 500,000-1 million cases.
Majority of new cases globally are in neonates. Neonatal tetanus, as it is known, is particularly common in rural areas where the infant is delivered outside a medical setting, with inadequate sterile procedures.
Anyone can acquire tetanus but the disease is particularly common and more severe in newborns. Mothers are that have not received tetanus toxoid vaccine are also at a great risk of developing the condition and subsequently passing it on to their children during birth. Tetanus requires treatment in a medical facility, often in a referral hospital.
Neonatal tetanus is often fatal. World Health Organization (WHO) estimated that neonatal tetanus killed about 30,848 newborn children in 2017, a 97% reduction in mortality rates when compared to 1988; when an estimated 787,000 newborns died of tetanus within their first month of life.
Tetanus is caused by the bacterium, Clostridium tetani.
Clostridium tetani is an anaerobic organism capable of surviving for many years, by transforming into a form known as a spore in order to withstand harsh environmental conditions.
Tetanus spores are present in the environment, usually in soil, dust, on rusty items, and animal faeces. When conditions are favorable, the spores transform into the infective bacterial form.
C. tetani produce two exotoxins (harmful chemicals); tetanolysin and tetanospasmin. Tetanospasmin is a neurotoxin (a toxin that affects the brain) which causes the manifestations of tetanus.
It is a common misconception that rust itself is the cause of tetanus. Rusty metals provide a favorable habitat for C. tetani maturation, coupling with its ability to injure the skin creating a route for infection by the bacteria. Please note that not all rusty metals have C. tetani on them.
Who is at risk?
Vaccination during childhood, in addition to booster doses every 10 years during adulthood, can prevent tetanus. Thus, tetanus occurs mainly in people who have not been vaccinated or who haven’t updated their vaccinations. This situation is more common in developing countries. In the United States, the risk of developing tetanus is high for the following populations:
1. Intravenous drug users.
2. People over 60 years, as immunity decreases over time.
3. People who were never given the tetanus vaccines, which is part of routine childhood vaccination.
How tetanus develops?
C. tetani usually invades the body through a wound.
Toxins are then produced by the bacteria, which is spread via blood and lymphatics. The tetanus toxin initially binds to a peripheral nerve and is transported along the nerve until it reaches the central nervous system (brain).
The muscle spasms characteristic of tetanus is as a result of the tetanus toxin interfering with the release of neurotransmitters, blocking inhibitory impulses. This leads to uncontrollable muscle contractions and spasm. Seizures may eventually occur.
How Tetanus manifests
Generally, the further the site of infection from the central nervous system, the longer it takes for symptoms to present and vice versa.
Clinically, three different forms of tetanus have been described.
1. Local tetanus: An uncommon form of the disease, in which patients have a persistent contraction of muscles at the site of injury. These contractions may persist for many weeks before gradually subsiding. Local tetanus may precede the onset of generalized tetanus but is generally milder.
2. Cephalic tetanus: This is a rare form of the disease, occasionally occurring with otitis media (middle ear infection) following injuries to the head. There is involvement of the cranial nerves, especially in the facial area.
3. Generalized tetanus: The most common type (about 80%) of reported cases. Usually presents in a descending fashion:
The first sign is lockjaw (trismus); which is a decreased ability to open the mouth due to reduced jaw motility,
Stiffness of the neck,
Difficulty in breathing and swallowing,
Rigidity of abdominal muscles.
Painful general body spasms lasting for several minutes (typically triggered by loud noise, physical touch or light).
Other symptoms include;
• Elevated temperature.
• Elevated blood pressure.
• Episodic rapid heart rate.
4. Neonatal tetanus (NT): A form of generalized tetanus that occurs in newborn infants.
In neonatal tetanus, symptoms usually appear from about 4 to 14 days after birth, with an average of about 7 days.
Neonatal tetanus occurs in infants born from a mother who is not vaccinated. Most often than not, it occurs through the use of a non-sterile instrument to cut the umbilical cord during delivery.
It is common in some developing countries but very rare in developed countries.
Neonatal tetanus usually presents with generalized muscle spasm which leads to death if not treated early.
How to MANAGE tetanus?
1. Supportive management.
a. Thorough wound cleaning and debridement (removal of compromised tissue and debris to improve wound healing).
b. The patient is kept in a quiet room to prevent stimuli that can trigger muscle spasms.
c. Management of presenting symptoms.
• Mechanical ventilation because of their potential inability to breath.
• Sedatives, such as diazepam may be given to help relieve pain and anxiety.
• Anti-hypertensive medication may be given to control high blood pressure if present.
• If swallowing is difficult, feeds may be given via nasogastric tube (a tube inserted through the nose into the stomach).
• If constipation is present, which is common, stool softeners are given.
2. Definitive management.
a. Antibiotics (usually metronidazole) are given to kill the bacteria which eventually stops the production of the toxins.
b. Tetanus immune globulin is injected into a muscle to neutralize the toxin already produced.
3. Long term management.
a. Tetanus vaccine is recommended unless vaccinations are known to be up-to-date.
b. After people recover, they are given one dose of the vaccine, followed by two more doses, separated by 1 month. Booster doses are given every 10 years.
Prevention of tetanus is a far better option than treating it. Vaccines are the ultimate way of preventing tetanus.
In young children, the vaccine is given as part of a routine vaccination schedule that includes diphtheria and pertussis (whooping cough) vaccine.
Individuals who have completed the primary series of tetanus vaccination should get boosters every 10 years.
Pregnant women are given tetanus, diphtheria, and acellular pertussis vaccine (Tdap) routinely during each pregnancy. Pregnant women who are vaccinated produce antibodies to tetanus that are transferred from the mother to the fetus during pregnancy and provide immunity to the child.
Thoroughly cleaning wounds can also help prevent tetanus infection. People who have suffered open wounds may be given a tetanus vaccine to prevent tetanus.
Complications of this infection may include:
1. Bone fractures.
2. Lung problems.
3. Respiratory failure (the most common cause of death).
4. Brain damage.
5. Abnormal heart rhythm.