Tetanus: Vaccine preventable deadly disease

Tetanus is a deadly disease. If one gets tetanus disease it becomes a big headache for everybody. Tetanus causes a really painful death to those who get a disease. Main feature of this limb is locked jaw and contraction of all the body muscles including limb muscles and back muscles. In severe cases, it may cause arching of the body, if there are contractures of the back muscles.

In 2015, approximately 34 000 newborns died from neonatal tetanus, a 96% reduction from 1988 when an estimated 787 000 newborn babies died of tetanus within their first month of life.

Cause of tetanus

Tetanus is an infectious disease. It is caused by infection of the bacteria Clostridium tetani. This is spore forming bacteria. It is gram positive motile and stays in soil or on corroded materials of metals. If the soil particles containing the spores of Clostridium tetani enter the wound it causes infection at the wounded site.

How does tetanus occur?

As we have discussed earlier tetanus disease occurs because of infection of Clostridium tetani bacteria. These bacteria live in soil. They can enter your wound from soil or corroded metal surfaces. The wound can be large or even a pin prick it may expose you to the deadly Clostridium tetani.

The infection and disease may occur to mothers during delivery of the baby or it may occur in babies and newborns through the injuries of the umbilical cord. The application of cow dung and other dirty material for the care of umbilical cord in newborn is dangerous.

Tetanus infection may also occur at the site of surgical wounds if the proper care was not taken and instruments used for surgery were not adequately sterilized.

Can it spread from one person to another?

Tetanus is a disease which is infectious in nature but it does not spread from human to human. You may get infected through your wound if the wound comes in contact with soil particles.

What is the incubation period of tetanus disease?

Incubation period is the property of infectious disease. It is the time period from person getting infection to first symptom of the disease in the same person.

Incubation period of the tetanus is from 3 days to 21 days average being 10 days duration.

Tetanus toxin

All the symptoms are caused by the tetanus toxin. This toxin is secreted by the Clostridium tetani in the affected wound. This toxin gets absorbed in blood and acts on nerve endings.

This toxin is called tetanospasmin or tetanus toxin. Tetanus toxin is one of the most potent toxins on the earth. Botulinum toxin is the only other toxin which is more potent than tetanospasmin. Estimated lethal dose of the tetanus toxin is 2.5 nanograms per kilogram of body weight (a nanogram is one billionth of a gram) or 175 nanograms for a 70-kg (154 lb) human.

What are symptoms of the tetanus?

From the above discussion you may have got some idea about the symptoms of tetanus disease. The symptoms of the tetanus are because of contracture of muscles and changes in the sympathetic-parasympathetic nervous system balance. The feature of this disease is that the patient’s consciousness is not lost till very advanced stages. With all these symptoms and pain, the patient really becomes locked in his/her own body.

In general common symptoms of the tetanus are as follows:

• Tetanus is also called ‘lockjaw’ because a person with tetanus disease presents with cramping jaws and inability to open the mouth. For the first time in tetanus disease the muscles of the jaw contract forcefully and involuntarily. These forceful muscle contractions make it difficult to open the mouth.
• With lockjaw the patient shows inability to swallow the food. There is throat pain.
• Over a few days the muscle contracture progresses to involve the limbs and other body parts. 
• The bouts of contracture of the muscles are intermittent initially and are induced by noise and light.
• Then these bouts become very frequent and last for a longer time and muscles may contract permanently.
• Ultimately back muscles also contract causing bowing of the body of the patient. It is called opistotonus posture.
• Finally muscles of breathing may fail landing patients to respiratory failure and death.
• During fever patients may show fever that may be moderate grade.
• There is a lot of sweating and fluctuations in blood pressure and increased heart rate. These symptoms occur because of failure of the peripheral nervous system.
• There is an increased amount of respiratory secretions and secretions from salivary glands. Patient is not able to swallow or cough these secretions and may cause choking.
• In neonates of unimmunised mothers tetanus first manifests as difficulty in feeding the baby. And progresses to paralysis and contractures.

How to diagnose tetanus disease?

Tetanus is a typical picture and does not need many tests to diagnose. It is diagnosed clinically.

In history the patient is not immunised and presents with a history of wound. In some patients the wound may be very small and may have forgotten about it.

There is difficulty in swallowing and opening the mouth with a lockjaw. After full clinical progression tetanus is typical. No other disease mimics tetanus.

Culture from wound site may be helpful if doubts but comes positive only in 30 percent cases.

What is the treatment for tetanus?

Tetanus is the deadly disease and saving patient is difficult but can be done with following strategies:

• Eradicating the tetanus bacteria from the wound is the first important step. The bacteria is susceptible to antibiotics. Antibiotics like penicillin or its derivatives may be used for treatment of the infection. Metronidazole and tetracyclines, erythromycin are some other antibiotics that can be used for the same purpose. 
• Healing of the wound may need surgical care and debridement. Surgical care and debridement should be done after giving adequate dosages of the tetanus immunoglobulin (TIG). 
• Giving tetanus immunoglobulin to neutralise the circulating toxin in the patient. TIG is given as soon as possible. It is given in 500 units. If it is not available IvIg and tetanus antitoxins may be used which are bovine derived products. Before giving tetanus antitoxin, patients should be checked for hypersensitivity reactions. Drawback of TIG is it can neutralise only the toxin circulating in the blood. It cannot neutralise the toxin that has already entered into the neurons. So symptoms may last till new axons are generated.
• Giving respiratory support throughout the therapy. During the disease the patient fails to breathe because of contractures of the muscles. Patients may die of respiratory failure. Precautionary intubation is recommended as it becomes difficult to intubate later on because of contracture of the jaw muscles. If intubation is not possible emergency tracheostomy procedure should be done. Adequate equipment and skilled personnel doing emergency tracheostomy should be available.
• For prevention and treatment of bouts of spasms patients should be given muscle relaxants like diazepam. The large doses of the diazepam may be needed for the same purpose.
• The tetanus patient should be managed in dark and calm room as slightest change in light and large noise may induce spasms in patients.
• Management of manifestations of imbalance of autonomic nervous system. The patients should be monitored closely to detect peripheral nervous system imbalance and its manifestations. Rigorous care should be done if there is fall in blood pressure and increased heart rate.
• Providing supportive care. Supportive care is utmost important. Regular cleaning should be done as secretions of saliva and respiratory secretions may cause choking and pneumonia. Patients may develop bed sores during the course of illness which may complicate the case causing sepsis. Patients with complications should be treated with consulting the other specialties if needed.
• Providing adequate nourishment. The treatment may last for many weeks. Patients should be provided with adequate nourishment. The food which is semi solid of liquid can be given with a ryles tube. Some patients with complications may need parenteral nutrition.
• Preventing the recurrences of the illness. After recovery from the illness, the patient may not be immune. The tetanus toxoid vaccine should be provided.

What are complications of tetanus?

Complications of the tetanus mainly occur because of the forceful and involuntary  spasms of the muscles. These complications include:

• Seizures and rigid paralysis related complications.
• Aspiration of secretion and pneumonia.
• Pneumothorax and mediastinal emphysema.
• Laceration of mouth and tongue.
• Hematoma and rhabdomyolysis.
• Myoglobinuria and renal failure.
• Long bone and spinal fracture.
• Venous thrombosis and pulmonary embolism.
• Gastric ulceration and paralytic ileus.
• Decubitus ulceration.
• Arrhythmia, unstable blood pressure and labile temperature regulation.

What is the prognosis of tetanus?

Prognosis of the patients depends on many factors. The illness may last for weeks and supportive care during illness is the key.

Patients with good prognosis are:

• Those with long incubation periods.
• Absence of fever.
• Localised disease.

Patients with bad prognosis are:

• Development of lockjaw within 7 days of injury
• Development of generalised spasm within 3 days of lockjaw

In children and infants long term sequelae may occur because of hypoxia and brain injury because of hypoxia. These patients may develop cerebral palsy in future.

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