Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis or Koch's bacillus, named after its discoverer, the German bacteriologist Robert Koch, in 1882.
Usually, the term tuberculosis is associated with pulmonary disease. In fact, although pulmonary tuberculosis is the most common, it can affect other organs such as the kidneys, genitals, small intestine, bones, etc. Despite the numerous possible locations of the disease, in about 90% of cases it begins in the lungs.
In adults, pulmonary tuberculosis, contracted by the respiratory system, directly (sputum droplets) or contaminated dust, is more common.
In children, as a rule, transmission occurs through ingestion of contaminated cow's milk, and pulmonary, kidney, bone, and skin tuberculosis may appear.
Bacilli that of tuberculosis
Why in the lungs?
Because Koch's bacillus reproduces and develops rapidly in oxygen-rich areas of the body, the lung is the main organ affected by tuberculosis.
Step 1 - Although it also affects various organs of the body, the disease is only transmitted by those infected with the bacillus in the lungs.
Step 2 - Dissemination happens through the air. The sneeze of an infected person throws about two million bacilli in the air. By coughing, about 3,500 particles are released.
Step 3 - Airborne TB bacilli remain in suspension for hours. Anyone who breathes in a tuberculosis environment can become infected.
The individual who first comes into contact with Koch's bacillus has no natural resistance yet. But you get it. If the organism is not weak, it can kill the microorganism before it becomes a disease. Protection against future bacillus infections is also established.
After a period of 15 days, the bacilli begin to multiply easily in the lungs, as there is still no natural protection of the body against the disease. If the defense system fails to trap the bacillus, primary tuberculosis, characterized by small lesions (lumps) in the lungs, sets in.
Over time and without treatment, disease progression begins to cause more severe symptoms. From small lesions, the bacilli dig into the so-called tuberculous caves in the lung, which often ignite and bleed. The cough in this case is not dry, but with pus and blood. This is called hemoptysis.
- Chronic cough (the hallmark of the disease is cough for more than 21 days);
- Night sweats (even wetting the sheet)
- Chest pain;
- Slow and progressive weight loss
- Those with tuberculosis do not feel hungry, become anorexic (without appetite) and adynamia (unwilling for anything).
The usual prevention is the vaccine BCG, applied within the first 30 days of life and able to protect against the most severe forms of the disease. If there is contamination, treatment basically consists of a combination of three drugs: rifampicin, isoniazid and pyrazinamide. The treatment lasts around six months. If the tuberculosis takes the medications correctly, the chances of cure reach 95%. It is critical not to stop treatment even if the symptoms subside.
Currently, it is the main worldwide concern regarding the disease. Abandoning the treatment causes the bacilli to become drug resistant and the drugs no longer work. Resistant tuberculosis can trigger a new wave of virtually incurable disease worldwide.
Incidence of disease
- 1/3 of the world's population is infected with the tuberculosis bacillus;
- 45 million Brazilians are infected;
- 5% to 10% of infected people get the disease;
- 30 million people worldwide may die from the disease in the next ten years;
- 6,000 Brazilians die of tuberculosis per year.