Tetanus ("barefoot disease") is an infectious (bacterial) disease with central nervous system damage, manifested by tonic and convulsive contractions of the striated muscles. This is the so-called "wound" infection, as the penetration of the pathogen into the body is carried out through a wound on the body. The disease can end with a fatal outcome. In patients with the disease, lifelong immunity is not formed, i.e., can be sick repeatedly. Tetanus is spread all over the globe. For the prevention of tetanus, routine vaccination is routinely used, beginning with the first months of life. In this article I will tell you about the causes and main symptoms of the disease.
Content
- 1Causes
- 2How does the disease develop?
- 3Symptoms
Causes
The cause of tetanus is the bacterium Clostridium tetani - an anaerobic rod with thickening at the ends in the form of spores (for which it is called a "tennis racket" or "drumstick"). Spores are found in the soil (favorite - chernozem, red soil), in the intestines of herbivores, rodents, birds and humans. Among animals, clostridia are found in feces of cows, pigs, horses, sheep, goats, rabbits, rats, mice, among birds - in chickens, ducks, geese. According to some reports, 40% of the population is able to carry the dispute in the human intestine, mainly due to people living in agricultural regions and working in the field of animal husbandry. The presence of spores in the intestine is not dangerous for humans and does not cause the development of the disease, but contributes to soil contamination. Spores get to a person directly from the soil through damaged skin or mucous membranes shell: in the presence of wounds, bites, burns, scuffs, punctures, just treshchinok on the skin (with walking barefoot). Also, the wind with dust clostridium are carried through the air, settling in apartment houses, operating, manufacturing enterprises, i.e. everywhere. In medical institutions where there are patients with any wound surfaces, there is also a risk of infection with tetanus (if the rules of asepsis and antiseptics are not respected).
Clostridium tetanus is very stable: in the soil, on the surface of furniture, clothes are kept for decades, not are exposed to chemical and physical factors (for example, spores can withstand temperatures of 90 ° C for 2 hours). Under favorable conditions (a lack of access to oxygen, a temperature of 37 ° C, good humidity) spores grow into vegetative forms that produce toxins. Vegetative forms are less stable: they are destroyed by boiling, treatment with disinfectants. Toxins are destroyed by exposure to sunlight, when heated, in an alkaline environment.
An increase in the incidence of tetanus is recorded in the spring-summer period ("summer" season).
A person with tetanus is not dangerous to others. It is impossible to get infected by caring for the patient.
How does the disease develop?
Spore enters the body through a wound and infects it with tetanus. T. e. if a part of the soil with clostridia enters the gastrointestinal tract, then this does not carry such a danger as, for example, soil penetration into the wound with a cut in the foot. The causative agent of tetanus is an anaerobic, i.e., develops in the absence of oxygen. Deep, closed wounds just contribute to this. So, in anaerobic conditions, where heat and humidity, the dispute turns into a vegetative form. This form begins to produce exotoxins: tetanospasmin, tetanohemolysin and protein, which enhances the synthesis of acetylcholine. Exotoxins are the danger, they cause all the symptoms of tetanus. Exotoxins that enter the intestines upon ingestion are not dangerous, since they are not absorbed.
Tetanospasmin is a very strong poison. Disappears with a current of blood and lymph throughout the body. It penetrates into the nerve fibers, then along the nerves moves towards the central nervous system, where it is densely fixed on the surface of the nerve cells. Tetanospazmin blocks inhibitory effects on motor neurons, "liberating" muscle activity. Any spontaneous impulses in the motor neurons in this case result in a contraction of the muscles, a constant tonic tension of the muscles arises. Visual, auditory, tactile, olfactory stimuli - sources of information from the environment - also cause an additional contraction of the striated muscles, provoking convulsions.
Tetanohemolysin causes destruction of erythrocytes, has a toxic effect on the heart cells. It plays a significantly smaller role in the development of tetanus symptoms.
Protein, enhancing the synthesis of acetylcholine, contributes to the strengthening of muscle contractions, potentiating the action of tetanospazmina.
Constant muscle contractions lead to an increase in body temperature, disruption of metabolic processes (metabolic acidosis develops), cardiovascular disorders. Due to the impossibility of relaxing the diaphragm and uncoordinated contraction of the intercostal muscles, respiratory failure is formed. The activity of the sympathetic nervous system increases, which is accompanied by an increase in heart rate, increased blood pressure, a violation of the rhythm of the heart. Possible damage to the respiratory and vasomotor centers in the brain, which can lead to the arrest of breathing and cardiac activity, because of which the patient may die.
Symptoms
According to prevalence in the body, local tetanus and general (generalized) are isolated. Local tetanus is the twitching of the muscles near the wound (the site of infection), often occurs in vaccinated persons, can go to generalized. The tetanus Rose is a variant of the local tetanus. It occurs after a wound in the head or neck area of vaccinated persons, accompanied by a lesion of the facial nerve, sometimes ptosis (omission of the upper eyelid), strabismus against the background of slightly expressed typical symptoms of tetanus, of which you will learn Further.
In the development of generalized tetanus, several clinical periods are distinguished:
- The incubation period is 1-60 days, more often up to a month. The shorter the incubation period, the more severe the disease, the worse the prognosis for the patient. Naturally, the closer the place of penetration to the central nervous system (head), the shorter the incubation period. By the end of this period, the patient may have a headache, sweating, general malaise, a feeling of tension and twitching in the wound. The onset of the disease can be unexpected, without any precursors (especially in cases where the entrance gates of the infection are unknown, for example, unnoticed by a patient scratching on the leg);
- the initial period lasts 1-2 days. There are dull, aching, pulling pains, burning in the wound (even if it has completely healed by this moment). It is possible to identify special symptoms: when massaging the muscles above the wound site, their convulsive contraction occurs; at tapping on a spatula placed on the teeth of the lower jaw, or on the cheek there is a reduction of chewing muscles and closure a slightly open mouth. Following this, typical tetanus symptoms appear: trismus, sardonic smile, dysphagia. Trism is a tonic tension and a convulsive contraction of the masticatory muscles, which leads to the inability to open the mouth. Sardonic smile arises from the reduction of facial muscles of the face, while the eyes are narrowed, the mouth is stretched, the corners of the mouth look down, the forehead is wrinkled, the impression of a simultaneous smile and crying. Dysphagia is a painful contraction of the muscles of the pharynx, a difficult painful swallowing (without eating). These three symptoms are specific, characteristic only for tetanus. Along with these symptoms, stiff neck may develop: tonic tension of the muscles of the posterior surface of the neck, in which it is impossible to tilt the head to the chest;
- the peak period lasts from one week to three. During this period, tonic muscle tension and convulsive contractions seize the entire body, as if descending from the head down to the legs. Brushes and feet are not involved in the process. The body is bent by an arch (opisthotonus), the head tilts back with support on the back of the head and the heel, the stomach becomes firm like a board, legs are stretched by a string, hands are bent at the elbows. In this position the patient is constantly, muscle relaxation does not occur. Patients experience terrible pain, remaining all the time in consciousness. Self-emptying of the bladder and intestine becomes difficult due to muscle spasm. Breathing is disturbed by the abrupt contraction of the diaphragm. Against this background of constant tonic muscle contraction, seizures occur periodically (either by themselves or under the influence of stimuli from the outside, which can be sounds, light, smells, drafts, touches, etc.). Seizures last from a few seconds to several minutes. Repeat several times a day, in severe cases - dozens of times per hour. The face of the patient at the same time expresses suffering, acquires a blue tint, the person becomes covered with sweat, salivation increases, the temperature rises to 41 ° С, arterial pressure rises, heart palpitations become more frequent, the pulse is strained, dyspnea becomes worse. The patients groan and scream, gnashing their teeth. At the height of seizures, choking can occur due to tetanic contraction of the muscles of the pharynx, larynx, diaphragm. Because of trismus and dysphagia, a person can not eat and drink, develops a painful insomnia, which does not act with usual sleeping pills. The contraction of the muscles is so pronounced that it can lead to rupture of the muscles, tear them from the place of attachment, to fracture of the vertebral bodies. Violation of the ventilation of the lungs leads to the attachment of a secondary infection and the development of pneumonia. The direct exposure of toxins to vital centers in the brain can cause the patient to die;
- the period of recovery - comes to the end of the 2 nd - 3 rd week (depending on the severity of tetanus). Gradually, the frequency of seizures decreases, muscle tone decreases, all symptoms go to "no." The process of recovery is long, up to 2 months. Strain in the muscles of the abdomen, back, chewing and calf muscles lasts long enough. In the absence of complications, a full recovery occurs.
Depending on the severity of the course, tetanus can be:
- easy - has a long incubation period (more than 20 days), indistinctly expressed trism, a sardonic smile and dysphagia. Stresses in other muscles are practically none, body temperature is normal or increased to 3, ° C. Symptoms of the disease are formed within 5-6 days. This form of the disease develops in patients with partial immunity;
- moderate - incubation period of 15-20 days. A complete clinical picture takes place in 3-4 days. A triad of typical symptoms is expressed, seizures occur several times a day, body temperature rises to 39 ° C, sweating, tachycardia;
- severe - incubation period of 7-14 days, symptoms occur within 24-48 hours. A pronounced muscular tension is accompanied by convulsive twitching several times an hour. The parameters of heart rate, pressure, temperature are sharply increased;
- very heavy - it is a lightning-fast form of tetanus, almost always resulting in death. The incubation period is less than a week, the symptoms increase on the eyes, an extreme increase in body temperature, almost incessant cramping. This form refers to the tetanus of Brunner (bulbar) - a kind of tetanus with the defeat of the respiratory and vasomotor centers in the central nervous system. Also very difficult is tetanus, which developed as a result of criminal (clandestine) abortions.
To determine the prognosis of the disease there is a special clinical sign: the shorter the gap between the triad of typical symptoms and the appearance of seizures, the worse for the patient.
Tetanus is a serious infection that can be prevented by vaccination. In the case when the disease still arose, early diagnosis is needed. The earlier this disease is suspected, the more likely the patient is to survive. You can learn about the possibilities of diagnosis, treatment and prevention from the following article.
A short video on the topic "Disease-causing human bacteria: tetanus"
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The TV channel "Russia-1 a broadcast about the most important on the topic "What is tetanus and how to deal with it »:
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