Opisthotonus in a tetanus patient
By Sir Charles Bell, Public Domain, Wikimedia
Tetanus is a disease caused by the toxins of a bacteria called clostridium tetani and manifests as persistent spasms of the muscles of the body. This can be very deadly especially when the muscles of the airway are involved (laryngospasms).
HOW DOES THIS DISEASE OCCUR
The microorganism called clostridium tetani is a rod-shaped bacteria that is found almost everywhere but mostly in the soil. It is also present in the air, saliva, house dust, manure, human and animal feces, and even around water bodies and slums. It produces spores that may not germinate for years and thrives very well in an environment that lacks oxygen. These spores are resistant to heat or any disinfection.
This bacteria gains access into the body through a wound on the leg from maybe a rusty nail, piece of wood, metal, thorns, etc, wound infection following child delivery or abortion, use of an unsterilized needle for injection, a fracture or anything that causes a breach in the continuity of the skin.
Source of tetanus - rusty metal
By Thester11 - Own work, CC BY-SA 3.0, Wikimedia
In the wound, when there is a condition of low oxygen, the spores produced by the bacteria germinate and release two toxins into the blood.
These two toxins are called Tetanolysin and Tetanospasmin. The first one does not cause many problems, but the second one, tetanospasmin is a very potent and dangerous toxin. It is carried from the wound site where it is produced to the brain and spinal cord where they get to the end plate of the neurons and block the inhibitory neurotransmission there.
The brain and spinal cord control the movements and activities of other tissues and organs by giving and receiving information from them through specialized structures called nerves. These nerves are like the biological electric cables which supply these organs/tissues. At the point where one nerve ends and another nerve/muscle begins is a junction called a synapse. This junction contains chemicals that help to relay information from the terminating nerve to the next structure which can be a nerve, muscle, or gland.
Synapse and neurotransmitters
By NIDA(NIH), Public Domain, Wikimedia
These chemicals here are called neurotransmitters and serve as chemical messengers to carry signals from one nerve to the next nerve, muscle, or gland. The neurotransmitters are of two types; the excitatory neurotransmitters which signal the next structure to continue firing (muscle contraction) and the inhibitory neurotransmitters which signal the next structure to stop firing (muscle relaxation). These two classes of neurotransmitters are well-balanced and tightly regulated to enable the normal functioning of the human body.
In tetanus, the tetanospasmin produced by the bacteria spores goes to these neuronal junctions in the central nervous system and blocks the inhibitory neurotransmitters (GABA and glycine) thereby leaving the excitatory neurotransmitters to continue to fire unopposed without inhibition. This unopposed firing leads to persistent muscle spasms which is the hallmark of tetanus disease.
The main muscles affected here are the muscles of the neck and jaw which causes these muscles to be tensely and painfully contracted without any relaxation. This is described as lockjaw/trismus which is the commonest presentation of tetanus. When the muscles of the face are affected, they present with a facial expression described as rhisus sardonicus (devil's smile). The spasm of the muscles of the neck, back, and lower extremities cause a painful backward arching of the patient described as opisthotonus.
Lock jaw
By CDC/Dr.Thomas F. Sellers/Emory University , Public Domain, Wikimedia
The spasm of the muscles of the abdomen here causes a board-like abdominal rigidity. However, the most dangerous of all these spasms are the spasms of the muscles of the airway (laryngospasms). This will cause the influx of the stomach contents into the lungs which are very very fatal.
Other clinical manifestations of this disease involve an autonomic dysfunction which causes dramatic changes in blood pressure, heart rate, and rhythm. These clinical manifestations usually occur within 14 days of infection.
HOW COMMON IS TETANUS
The incidence of tetanus has dropped greatly in the developed world with proper vaccine coverage and environmental hygiene. However, it is still a public health challenge in low-income countries where many persons are still not fully vaccinated against the disease.
In 2019, the Global Burden of the disease was estimated at over 73,000 total tetanus cases including over 27,000 neonatal tetanus infections.
In 2015, about 34 000 newborns died from neonatal tetanus, a 96% reduction since 1988, largely due to scaled-up immunization with Tetanus Toxoid Containing Vaccine (TTCV).
In countries with no intensive care, almost 100% of persons who get infected with tetanus die.
WHO THOSE AT RISK OF THIS DISEASE
Tetanus is very preventable and with full vaccination, everyone can be protected from this disease. Those at risk of getting tetanus are those who have not been fully vaccinated against tetanus as well as those fully vaccinated but have not been taking their booster doses as recommended.
Neonatal tetanus
By CDC, Public Domain, Wikimedia
INVESTIGATIONS
There is no investigation to make the diagnosis of tetanus. It is a clinical diagnosis meaning that from the patient's history and physical examination, you will be able to know that a patient has tetanus.
TREATMENT OF TETANUS
A patient with tetanus is always nursed in a dark and quiet room because light and sound trigger more spasms.
The next is to the first of all remove the source of the toxins which are the spores being produced in the wound. So the wound is properly irrigated and all wound debris removed. After which the toxins already circulating in the blood will be neutralized using the human anti-tetanus immunoglobulin or anti-tetanus Serum.
Benzodiazepines are then given to control the muscle spasms. Further management includes the use of Antibiotics to clear the microorganisms, maintenance of patent airway, proper nutrition, prophylaxis for stress ulcers and deep vein thrombosis as well as drugs to control the autonomic dysfunction.
PREVENTION
Tetanus affects all persons of all age groups including pregnant women and newborn babies which contribute a good percentage of this disease. Tetanus in newborns results mainly from unhygienic birth practices which are found in developing and low-income countries. Therefore, prevention of maternal and neonatal tetanus is a very great step in reducing the incidence of tetanus in our environment.
Vaccination
By U.S. Navy photo, Public Domain, Wikimedia
Adequate vaccination has proven to be the most effective and adequate tool for protection against tetanus. To be fully immunized, 6 doses of the vaccine are usually recommended with booster shots throughout life.
WHO recommends a schedule of three primary infant series followed by three booster doses at the second year of life, that is at 12 – 23 months, 4 – 7 years, and 9 – 15 years, which could provide life-long immunity against tetanus. Ideally, there should be at least 4 years between booster doses.
For those who are not adequately immunized, a booster shot should be given once there is an injury suspected to be at high risk of tetanus, usually given within 48 hours.
All pregnant women should also receive adequate doses of Tetanus vaccines to protect them and their babies from Tetanus.
Good wound care and adequate personal and environmental hygiene are also very helpful in protecting us against tetanus.
In conclusion, tetanus is a very serious neurological disorder that affects all genders and age brackets. Even though the incidence has dropped so well in the developed world, it has remained a public health problem in developing countries, especially in Africa. The good news is that the disease is very much preventable with vaccines. But so many persons are still unvaccinated which puts them at risk of this serious disease.
The tetanus vaccine is very safe and available and we must all be adequately vaccinated. Every pregnant woman should also ensure to get adequate doses of the vaccine to protect the mother and child from maternal and neonatal tetanus.
Together, we can have a tetanus-free world through vaccination. GET VACCINATED TODAY!
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