What is Tetanus?
Tetanus is a serious disease that affects the nervous system and is caused by bacterial infection of deep wounds, characterized by repeated bouts of painful muscle spasms. The disease is also called “Lockjaw” because it causes stiffness of the neck and jaw muscles in an infected person, making it too difficult to open the mouth or swallow, and causes breathing difficulties. The disease has been known to man for ages and still remains a public health threat in various parts of the world, especially in resource-limited settings where immunization coverage is low and unclean birth practices are common. Individuals of all ages are susceptible to contracting tetanus, but the disease is particularly common and severe in infants and their mothers due to infection from the use of unclean surgical equipment during child delivery and lack of vaccination.
What causes Tetanus?
The disease is caused by the bacteria Clostridium tetani, which produces dormant spores that can survive in soil, dust and human faces for years, and can gain entry into the body through deep cuts and puncture wounds from contaminated objects like nails or pieces of glass. The bacteria thrive in anaerobic conditions (low oxygen), thus, puncture wounds are a good site for their growth. Upon entry into the wound, the bacterial spores germinate to give rise to active bacteria, which actively grow and divide due to the anaerobic condition in the wound, simultaneously releasing a potent toxin called “Tetanospasmin” that affects the nervous system. Tetanospasmin is one of the most potent microbial toxins ever known to man, and acts by inhibiting the nerve cells that regulate muscle contractions in the body. As a result, the muscles begin to contract more forcefully and more frequently, causing the excessive muscle spasms characteristic of tetanus. Risk factors that make an individual susceptible to contracting tetanus include deep wounds caused by nails or splinters and exposed to soil or manure, an infected umbilical cord during birth delivery of an unvaccinated mother, use of unsterilized surgical equipment, shared use of contaminated needles among drug abusers, and infected skin lesions in people living with diabetes.
What are the Signs and Symptoms of Tetanus?
The total incubation period of the bacteria ranges from 3 to 21 days, but the average time from infection to manifestation of symptoms is about 10 days. There are four forms of tetanus, which are generalized, localized, cephalic and neonatal tetanus. Generalized tetanus is the most common and is mainly characterized by stiffness and painful muscle spasms starting from the jaw and neck, and then progressing to other parts of the body. The patient experiences difficulty swallowing, fever, diarrhea, intense headaches, rapid heartbeat, sweating and muscle rigidity. There is uncontrolled tension in the muscles around the mouth, resulting in a characteristic persistent grin called “risus sardonicus”. During intense muscle contractions involving the whole body, the arms are folded against the sides, the legs are fully extended, and the neck and abdomen are arched with the head thrown backwards, giving a peculiar, tensed posture called “opisthotonos”, which is a definitive sign of generalized tetanus (see illustration). At times, the muscle contractions can be so powerful that bone fractures and tendon dislocations may occur, which further worsens the state of the patient.
These muscle contractions can be induced by stimuli such as noise, bright light and physical touch, thus, such patients are kept in very quiet isolation to minimize the presence of such stimuli. Without adequate medical attention, severe cases of generalized tetanus usually result in death due to breathing difficulties caused by muscle rigidity of the neck and abdomen, or damage to nerves that regulate vital functions such as breathing and heart rate.
Localized tetanus is characterized by persistent contractions involving only the muscles around the infected wound, but this can eventually become generalized if left untreated. Cephalic tetanus involves the muscles of the face and is caused by head injuries that got infected or ear infections that spread to the nerves of head. Damage of the facial nerves results in facial palsies characterized by a drooping appearance on one side of the face. It can progress to generalized tetanus if left untreated, and can be fatal. Neonatal tetanus occurs in infants, mostly as a result of using unsterile surgical equipment to operate on the umbilical cord during childbirth. As a result, the infant becomes infected and develops contractile symptoms similar to that of generalized tetanus within 28 days of birth. Neonatal tetanus is a major cause of infant mortality in underdeveloped countries worldwide.
How can Tetanus be diagnosed?
The symptoms of tetanus are very peculiar and cannot easily be mistaken for other diseases; hence, presence of the symptoms demands immediate commencement of treatment. However, for the sake of confirmation, a blood test and laboratory culture can be carried out to confirm the presence of the causative bacteria. Anyone with signs of muscle stiffness and spasms is advised to seek expert medical attention immediately. The earlier the diagnosis, the more effective the treatment will be.
How can Tetanus be treated?
There is no specific medication for treating the disease. Treatment is usually by management of symptoms. The muscle spasms and stiffness can be treated with anticonvulsants (like Diazepam), muscle relaxants (like Baclofen), and neuromuscular blockers (like Pancuronium). Antibiotics like Penicillin, Metronidazole and Tetracycline can be administered to the patient to limit bacterial multiplication and toxin production. Tetanus patients must be given adequate nourishment, as they require a high daily calorie intake due to increased muscle activity. Ventilators can be used to support patients that have difficulty breathing if their respiratory muscles are affected.
How best can Tetanus be prevented?
Persons with any deep cuts, wounds or burns should seek immediate medical attention to have their injury cleaned thoroughly to prevent infection. Such injuries must be properly dressed to prevent contact with soil and other sources of infection. The individual should be given a shot of Tetanus Immunoglobulin (TIG) quickly, as it contains antibodies that kill the causative bacteria and provide short-term protection against tetanus. However, vaccination remains the most effective method of preventing tetanus infection. The tetanus vaccine is usually administered as part of the DTaP vaccine against Diphtheria, Tetanus and Pertussis (whooping cough). The vaccine is routinely given in five shots with monthly intervals. At the age of 11 to 18 years, a booster shot is necessary to maintain immunity against the disease, and such booster shots should be continually given every 10 years, especially in regions where tetanus is common.
Reference
- World Health Organization. Tetanus. https://www.who.int/health-topics/tetanus#tab=tab_1
- Felman A (2017). Everything you need to know about Tetanus. Medical News Today. https://www.medicalnewstoday.com/articles/163063
- Hinfey PB (2019). Tetanus. Medscape. https://emedicine.medscape.com/article/229594-overview#a2