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Tetanus

Overview

Tetanus is a rare but serious disease caused by a bacterium that exerts its disease effects by producing a toxin. The toxin attacks the part of the nervous system that controls muscles’ contractions, causing spasms, particularly of the jaw, face, and neck muscles. The most typical presentation of the disease is “Spasm of the jaw,” also known as “ lockjaw,” which is characterized by an inability to open the mouth. It can affect all the muscles of the body, of which the respiratory muscles lead to respiratory failure and death.  A vaccine against tetanus yields complete protection. It mainly affects people who are not vaccinated or have not taken the full vaccination course. It is common in developing countries. 

Causes

Tetanus is caused by the bacterium Clostridium tetani, which is found in the form of spores in soil and manure of cattle. The spores are resistant to killing by heat, disinfectants, or boiling and can survive long. The spores of the bacteria enter the body through cuts or wounds in the skin and multiply and release a toxin that affects the nerves controlling muscular contractions, causing stiffness and spasms of the muscles. Tetanus is not transmitted from one person to another.

Risk Factors

The factors that can increase your chances of being infected with the bacteria are;

·         Being unimmunized or incompletely vaccinated

·         Old age, more than 50 years because of immunity decline

·         Being wounded by a rusty nail (as a nail might have got rusted in a humid, damp environment containing spores)

·         Working in an agricultural field with already having cuts or grazes in the skin

·         Having Burn wounds

·         Get bitten by an animal

·         Getting body piercings, tattoos, injections

·         Injuries, trauma

·         Using contaminated heroin

·         Rarely via surgeries, dental procedures

·         Unhygienic treatment during home delivery of a baby

·         Improper care of the umbilical cord

Epidemiology

With tetanus immunizations, tetanus cases have been reduced in the USA. Most cases arise in unvaccinated people, incompletely vaccinated people, older adults, drug abusers, etc. It is more common in Hispanics due to increased drug abuse. It affects neonates, young adolescents, older adults more than people in their middle age.

The incidence of tetanus globally is 0.5-1 million cases per year. It is more common in developing countries with inadequate immunizations programs, like Africa. It prevails in rural areas with soil cultivation, cattle rearing, warm climates, summer seasons, and in males. 

Signs And Symptoms

The period between being inoculated with bacteria and the appearance of symptoms is called the incubation period, which is around 3- 21 days in case of tetanus. It begins with the face and neck muscles and then slowly progresses to involve the whole body. The signs and symptoms of tetanus are;

·         Lockjaw - Inability to open mouth

·         Persistent smile called risus sardonicus

·         Spasm of muscles of the back of the nape

·         Spasm of muscles involved in swallowing

·         Stiffness of abdominal muscles

·         Generalized muscle rigidity

·         Severe cases may also cause disruptions of some body functions like blood pressure, heart rate, temperature, etc.

·         Opisthotonos: Intermittent reflex spasms cause tonic contractions of the arms, fists clenching, curving of the back, straight rigid legs brought on by stimuli like noise, touch, etc. These episodes can cause bone fractures, rupture of the muscle tendons and may cause severe pain and death by acute respiratory failure. 

Diagnosis

Diagnosis is made based on the clinical presentation. Your healthcare provider will look for the typical symptoms while taking history and the illicit signs during physical examination. No other laboratory tests can confirm the infection.

Your doctor may perform the ‘spatula test,’ where the posterior wall of your throat is touched with the soft tip spatula, and the effect is noted. If you bite the spatula, the test is positive for tetanus. If you have a gag reflex, the test is negative. 

Differential Diagnosis

Some diseases may look like tetanus are needed to be excluded;

·         Temporomandibular joint dislocation

·         Aseptic Meningitis in children

·         Encephalitis

·         Seizure disorder

·         Hemorrhagic Stroke

·         Bacterial Meningitis in children

·         Drug reactions causing dystonia (e.g., metoclopramide, phenothiazines)

Treatment

Tetanus is managed by providing specific as well as supportive treatment. The specific treatment includes;

·         Tetanus immunoglobulin (TIG), also known as tetanus antitoxin or tetanus antibodies. It can be given in injection either in the vein or the muscle.

·         Antibiotic is given to reduce toxin production. The antibiotic of choice is metronidazole. Injecting it in the vein is preferred.

The supportive treatment includes;

·         Benzodiazepines are medicines that control spasms. Examples include diazepam, lorazepam given by mouth or injected in the vein.

·         Severe cases are admitted in the ICU. To maintain the airway and breathing, a procedure called tracheostomy is performed in which a small hole is made surgically in the skin and trachea (windpipe), and a tube is placed through which air can go in and out. The tube can also be attached to a ventilator for mechanical ventilation.

·         In some severe cases, intravenous infusion of magnesium sulfate can be given to control spasms and autonomic dysfunctions.

·         A high caloric diet is given either via veins or a small tube placed directly in the stomach after minor surgery.

·         Recovery occurs in 4-6 weeks. 

Prognosis

Tetanus is a rare but fatal infection. The earlier the diagnosis is made, the better it can be managed. The short incubation period, extremes of ages like very old and neonate, lesions of the head and face are associated with poor outcomes. Tetanus usually does not result in residual neurological sequelae and does not render lifelong immunity. A person needs to be vaccinated even after suffering a tetanus infection.

Prevention

The most important prevention is provided by the vaccine. Children under 7 years of age are given a combined vaccine called DPT/DTaP vaccine, which protects against tetanus, diphtheria, and pertussis (whooping cough). For children and adults over 7 years of age, the Td vaccine protects against tetanus and diphtheria, or the Tdap vaccine is given, which gives protection against tetanus, diphtheria, and pertussis. A booster is recommended every 10 years for adults and people unaware of their vaccination status and are injured. The wound should be taken care of by proper cleaning, rinsing, bandage, and antibiotic application.

Our clinical experts continually monitor the health and medical content posted on CURA4U, and we update our blogs and articles when new information becomes available. Last reviewed by Dr.Saad Zia on May 09, 2023.

 

References

https://www.cdc.gov/tetanus/index.html#:~:text=Tetanus%20is%20an%20infection%20caused,open%20the%20mouth%20or%20swallow.

https://onlinelibrary.wiley.com/doi/full/10.1111/jnc.15330

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