Tuberculosis rod: how much does it live, how is it transmitted? What is tuberculosis?

Tuberculosis is an insidious disease that affects not only adults but also children. The disease causes the activity of mycobacteria (Koch sticks) in the human body. In the treatment of pathology, multicomponent chemotherapy is used, which can last up to six months or more. In 50% of cases of absence of treatment, the disease ends in a lethal outcome. What is Koch's tubercle bacillus, how does it get into the human body and how to prevent the development of the disease? We will deal with these issues in our article.

The concept of mycobacterium

Tuberculosis is an infectious disease, caused by Mycobacterium tuberculosis (MBT) mycobacteria. This kind of bacteria is often called Koch sticks - after the name of the German scientist Robert Koch. The science knows about 74 species of mycobacteria that live in soil, water, in the body of animals and humans. I must say that the strains of tuberculosis, caused by various types of mycobacteria, differ from each other.

Tuberculosis bacillus has a special protective coating, which helps the bacteria to survive in environmental conditions. MTB has a straight or slightly curved shape, immobile, does not form capsules or spores, very slowly multiplies by elementary division into two cells, with the fission cycle being 14-18 hours. As a rule, reproduction occurs in two ways - by budding, less often by branching.

The dimensions of the mycobacterium are negligibly small: the diameter varies between 0.2 and 0.6 microns, and the length is 1-10 microns. Tuberculosis bacillus is referred to fungi, because their similarity is manifested in the same consumption of oxygen. MTB colonies slowly (within 34-55 days) grow on a dense nutrient medium, have a rough surface, slightly pigmented - pink-orange or milky.

MTB cell structure

Bacterial cells of tubercle bacillus consist of the following elements:

• Cell wall - is formed by several layers that protect the mycobacterium from mechanical and chemical effects; Ensures the consistency of the size and shape of the cell (by the way, waxy, fatty substances enter the composition of the protective shell);
• Bacterial cytoplasm with granular inclusions;
• Membrane of the cytoplasm;
• Nuclear substance, in which one ring DNA.

The MBT is very resistant to the environment and remains viable for a long time. How much does a tubercle bacillus live? Mycobacterium can survive: up to 7 years in a damp and dark place at a temperature of 23 ° C; Up to 12 months in a dark and dry place; Up to 6 months in soil; Up to 5 months in water; Up to 3 months in books; Up to 2 months in the street dust; Up to 2 weeks in raw milk; Up to a year in butter and cheese. Mycobacterium tuberculosis is not afraid of rotting processes and a few months can exist in bodies buried in the ground. However, direct rays of the sun destroy the MBT for one and a half hours, ultraviolet rays - in a few minutes. Chlorine-containing disinfectants cope with the bacillus in 5 hours. Mycobacteria are also sensitive to hydrogen peroxide. The tuberculosis rod dies when heated: for 20 minutes at 60 ° C and for 5 minutes at 70 ° C.

The MBT can cause the disease after two to three years of asymptomatic existence and for a long time to excite anti-tuberculosis immunity in the body.

What is tuberculosis?

As noted earlier, tuberculosis is an infectious disease caused by the activity of mycobacteria. Most of the disease spreads airborne from an infected person to a healthy person on contact (coughing, sneezing, talking). Sometimes the infection can be food-like (raw milk).

In the risk group - people who are constantly in rooms with unfit sanitation - prisons, houses for the homeless. This includes patients with weakened immunity (HIV-infected, cancer patients). Diabetes patients; Infants; The elderly; Family members suffering from tuberculosis; Smokers; People with poor nutrition - these categories of citizens are most often attacked by a tuberculosis bacillus. The way of a food assumes obligatory consumption of vitamins and microcells, helping to restore the reduced functions of immunity.

The incidence of tuberculosis is determined by the individual characteristics of the body, and is also directly related to the psychological state of a person. The age group is dominated by a group of people aged 18-26.

The peculiarity of this pathology is that the tuberculosis rod quickly acquires resistance to medicines, therefore the treatment technique involves the use of several drugs at the same time.

According to WHO statistics, about a third of the world's population is infected with Koch's stick, however, a healthy organism does not allow the MBT to multiply. Pathology occurs in the human body only under favorable conditions for this - reduced immunity. Annually from complications caused by tuberculosis, around three million people die in the world. World TB Day is held on 24 March.

Ways of transmission of tuberculosis

There are four main ways in which the tubercle bacillus spreads:

• Airborne, when mycobacteria enter the air with droplets when coughing, sneezing;
• Alimentary - infection occurs through the gastrointestinal tract;
• Contact - infection occurs through the conjunctiva of the eye (infection through the skin is a rare occurrence);
• Intrauterine infection - infection through the affected placenta during childbirth from mother to child.

In a healthy body, the breathing system is protected from the penetration of mycobacteria by mucus, which is secreted by special cells. However, with inflammation of the respiratory system, as well as under the influence of toxins, "protection" does not work. The likelihood of infection by alimentary tract depends on the condition of the intestinal wall, its absorption capacity.

Since the tubercle bacillus is outside the cell and multiplies slowly, the tissues retain their healthy structure for some time, however, mycobacteria after some time with the current of lymph enter the lymph nodes and spread throughout the body. The most favorable for mycobacteria are organs with a developed microcirculatory bed (lung, cortical layer of the kidneys, parts of the fallopian tubes). As soon as MBT penetrate into the cell, they begin to damage its structure and divide.

Anatomy of pathology

In organs affected by infection, there is a "cold" inflammation, which leads to the formation of a multitude of granulomas - hillocks prone to decay. The body reacts several weeks after infection. Cellular immunity is formed after two months. The next phase of the development of the pathological process is characterized by a slow growth of MBT, the inflammatory reaction disappears, however, the pathogen from the focus of inflammation is not completely eliminated.

The tuberculosis bacillus remains in the body for a long time, and a person can be a lifelong carrier of the MBT. With weakening of immunity, the remaining population of the MTBT will begin to actively share, causing a consistent development of tuberculosis. The risk of developing a pathology in a newly infected person is 10% during the first two years after infection. Over time, the likelihood of the disease will decline.

With weakened immunity, the body can not withstand the multiplication of bacterial cells, which occurs in geometric progression. For the life of the MTB a special favorable environment is formed, in which the isolated granulomas merge into a total volume, while they say that the primary infection passes into the phase of clinical tuberculosis. The inflammatory process extends further throughout the functional system.

Forms and types of tuberculosis

After infection, the pathology acquires a latent form, i.e., most often it is asymptomatic. Only one out of ten cases passes into the active phase. Tuberculosis rod mostly affects the lungs, but it can also damage other body systems.

There are two forms of tuberculosis:

• Open,
• Closed.

With an open form, the presence of a tubercle bacillus is easily detected in sputum or in other discharge of the patient (urine, feces). Failure to observe hygienic precautions with this form can lead to infection of others. With a closed form, mycobacteria are not found, and patients do not pose a threat to others.

Depending on which functional system is exposed to the tubercle bacillus, the pathology is classified into:

• pulmonary tuberculosis,
• Extrapulmonary tuberculosis.

Depending on how much the pathology has spread in the body, distinguish:

• Latent tuberculosis,
• Disseminated tuberculosis,
• Focal tuberculosis,
• Caseous pneumonia,
• Tuberculosis,
• Fibro-cavernous tuberculosis,
• Cirrhotic tuberculosis,
• Tuberculosis of the pleura, larynx or trachea is a rare phenomenon.

Extrapulmonary tuberculosis affects any other organ, according to which pathology is classified into:

• Tuberculosis of the central nervous system and brain envelopes - the disease affects the spinal cord and the solid membranes of the brain;
• Organs of the digestive system, which, as a rule, affects the small and small intestine;
• Tuberculosis of the urogenital organs affects the kidneys, urinary tract, genitals;
• Bone structures;
• lupus;
• Tuberculosis of the eye.

Clinical manifestations of pathology. Central tuberculosis

As mentioned earlier, because the tubercle bacillus is divided very slowly, it is impossible to detect it at the earliest possible time. Therefore, the pathology may not manifest itself for a long time, and later it may be discovered by chance during fluorography or tuberculin tests. In addition, the specific signs of the disease, in fact, does not exist. The fact that intoxication occurs in the body may indicate the pallor of the skin, chronic fatigue or lethargy, apathy, a slight increase in body temperature (about 37 ° C), excessive sweating, decreased body weight, increased lymph nodes.

A laboratory analysis of the blood of patients with tuberculosis reveals a lack of iron, a decrease in the number of leukocytes. Later, when the disease goes into a more active phase, the above symptoms will be accompanied by obvious signs of the pathology of the affected organ.

If mycobacterium affects the central nervous system, the patient is observed, in addition to high temperature, sleep disorder, aggression, severe headaches, vomiting. At the end of the second week from the onset of the first signs, changes occur in the structures of the cerebral cortex, which are characterized by the tension of the neck muscles and the inability to press the chin to the chest, maximally stretch the legs. Patients with diabetes mellitus or carriers of the immunodeficiency virus are at risk. It is not uncommon for mental disorders to arise against the background of this pathology, as well as disorders of consciousness, sensitivity, movement of eyeballs.

In contrast to the disease in an adult, tuberculosis in children causes a different course of the disease, more rapid and severe, sometimes leading to death. This is based primarily on the underdeveloped immune system of the child. Suffered this pathology more often children who are in conditions of unsanitary conditions, eat poorly, constantly overwork. Tuberculosis bacilli in children causes specific symptoms in the body, so the attention of parents should be vomited, fast fatigue of the child, reduced attention, loss of appetite, weight loss, fever.

Tuberculosis of other functional systems

In addition to the lungs and elements of the central nervous system, pathology can attack other organs in the human body, for example, the respiratory system. Thus, tuberculous pleurisy is a lesion of the pleura, a membrane that covers the lungs. This pathology can be an independent disease, or arise due to a complicated course of pulmonary tuberculosis. Another complication of pulmonary tuberculosis may be tuberculosis of the upper respiratory tract, when the pharynx and larynx are involved in the inflammatory process. Symptoms of this disease, in addition to the above, are hoarseness or difficulty in swallowing.

The defeat of the lymph node Koch is called tuberculous lymphadenitis. Most often, the attack is performed by supraclavicular or cervical lymph nodes, which are enlarged but painless.

MTB can affect the organs of the genitourinary system. The disease manifests itself by sharp pains in the lower back or back, high body temperature. When urinating, bleeding may occur. Pathology occurs in an equal proportion in both women and men.

Tuberculosis of bone tissues is characterized by frequent fractures, severe pain in the area of injury, inability to move normally. Running forms of such pathology often lead to a lethal outcome.

Diagnosis and treatment

In the diagnosis of the active form of tuberculosis, the most popular methods are microscopic examination of sputum and fluoroscopy. Smear analysis, however, can not be called a reliable and unambiguous method, since in the early stages of pathology, as well as in the case of the manifestation of the disease in children, the study gives a negative result.

X-ray diagnostic methods are effective mainly in the late stages of the disease. In addition to these methods of diagnosis, a cutaneous tuberculin test is often used, which in the common people is called the Mantoux reaction.

The main task in choosing a patient's treatment regimen is to study the drug resistance of the pathogen, i.e., the sensitivity of the culture of mycobacterium grown in laboratory conditions to medicament preparations.

Today the main method of treating tuberculosis is anti-tuberculosis chemotherapy, which is polycomponent. There are three-component, four-component and five-component treatment regimens.

The three-component scheme involves the use of three main drugs - Streptomycin, Isoniazid and para-aminosalicylic acid (PASC). This scheme is classical, however, today it is rarely used due to the high toxicity of PASC. In a four-component procedure, use "Rifampicin" ("Rifabutin"), "Isoniazid", "Pyrazinamide", "Etambutol". Many medical centers use an even more progressive technique - a five-component scheme that, in addition to the four drugs mentioned above, uses "Ciprofloxacin".

I must say that tuberculosis is an insidious disease, to the development of which the tubercle bacillus leads in the human body. Treatment should be immediate and correct, because in the absence of therapy, the death from pathology ends with 50% of cases. The lethal outcome occurs within several years from the moment of the onset of the active phase of the disease. The remaining 50% of cases lead to a chronic form of the disease. And the patient, who has chronic tuberculosis, is dangerous to others, as it secrete mycobacteria into the environment.

Prevention

To the preventive measures against tuberculosis for today it is possible to attribute, perhaps, the vaccine BCG, which effectively protects against one of the most dangerous forms of tuberculosis - tuberculous meningitis. According to the National calendar of preventive vaccinations, the child is vaccinated even in the hospital in the first 3-7 days of life. Further, at 7 and 14 years, revaccination is carried out under the condition of a negative Mantoux reaction and no contraindications.

The BCG vaccine (Calmette-Geren bacillus) shows excellent results, but mandatory vaccination against tuberculosis is not accepted in all countries of the world, it all depends on the incidence of tuberculosis in the region. A few months after vaccination, a skin reaction appears at the injection site - a small seal.

Vaccination to the child is contraindicated if:

• The newborn has an immunodeficiency, and when there are persons suffering from this pathology in the infant's family;
• The siblings of the newborn had complications after such a vaccination;
• The child has congenital pathologies of the central nervous system.

Vaccination is postponed if:

• The child is not full,
• He identified any infectious disease,
• The mother and child have different Rh factor.

It is important to remember that a hard-to-cure disease is caused by a tubercle bacillus. Eating a sick person with therapy should be healthy and proper. Avoid excessive consumption of fatty foods. Assimilation of such nutrition in patients with tuberculosis is difficult. This is due to the anatomical structure of the MTB cell - its envelope contains a lot of fats. A person with pathology needs food rich in proteins, carbohydrates, vitamins and microelements.

To minimize the likelihood of primary infection at home, you must follow the rules of hygiene, spend more time in the fresh air, hang out in the sun woolen and cotton products.