Tuberculosis is a serious infectious disease but, with appropriate therapy, it can be cured. It is transmitted by air through tiny droplets of saliva, containing the bacterium. Mycobacterium tuberculosis, spread with coughing, and / or sneezing of infected people.
It mainly affects the lungs (in this case we speak of pulmonary tuberculosis) but it can also affect other parts of the body such as, for example, glands, bones and nervous system (in this case we speak of extra-pulmonary tuberculosis) (Video).
Before the introduction of antibiotics, tuberculosis was a major health problem worldwide. Today, thanks to the availability of these drugs, it has become relatively rare.
In recent years, the number of cases has progressively increased, particularly in populations living in developing countries where tuberculosis is more common.
According to the estimates of the "World Health Organization (WHO)" Global tuberculosis report 2018 ", in 2017 in the world there were 10 million new cases of tuberculosis and 1.6 million deaths (of the 10 million new cases estimated, only 6.4 million were notified to the WHO).
The data of the WHO indicate that in Italy, in 2017, 3944 cases of tuberculosis were notified (read the Bufala). The number of new cases (incidence) estimated was equal to 6.3 per 100,000 inhabitants, a value that places the "Italy among the countries with a low incidence of tuberculosis.
It has been estimated that around 1/4 of the world's population is exposed to Mycobacterium tuberculosis (mycobacterium of tuberculosis) but, under certain conditions, only 10% develop the disease. The remaining 90% will never have the signs of infection (latent tuberculosis) nor will they be able to pass it on to others.
In the early decades of the 1900s, a vaccine was produced for pulmonary tuberculosis, the vaccine of Calmette-Guérin, consisting of live, attenuated (ie “weaker”) mycobacteria of bovine tuberculosis. Although effective in children, the vaccine's effectiveness in preventing the disease ranges from 0% to 80% in adults.
Currently, vaccination is strongly recommended for people at high risk of getting tuberculosis such as, for example, children living in areas where the disease is widespread, such as some areas of Africa, Russia, China, South America. .Symptoms
The disorders (symptoms) caused by tuberculosis vary according to the organ affected.
Tuberculosis mainly attacks the lungs, causing coughing with phlegm (sometimes with blood) that lasts over three weeks and difficulty in breathing that gradually worsens.
There extra-pulmonary tuberculosis it is less common, affecting various organs such as lymph nodes, bones, joints, digestive system, bladder, reproductive system and central nervous system. The disorders (symptoms) caused by extra-pulmonary tuberculosis vary and can include swollen lymph nodes, abdominal pain, pain and loss of movement in the affected limb or joint, confusion, persistent headache, seizures.
Extra-pulmonary tuberculosis is more common in people with a compromised body's defense system (immune system), such as those with AIDS.
The evolution of the disease is slow and the disturbances (symptoms) can begin to manifest themselves after months, or even years, from the initial contact with the bacterium. In some people, the infection does not cause any discomfort (it is asymptomatic). In these cases, those affected do not infect others and may never get sick for the rest of their lives (latent tuberculosis).
If, on the other hand, a series of disorders (symptoms) such as lack of appetite, weight loss, fever, night sweats, tiredness and fatigue appear, we speak of active tuberculosis.
However, these disorders could also have an "other origin and not necessarily be attributable to tuberculosis.Causes
Tuberculosis is an infectious disease, which is transmitted by air following contact with the Mycobacterium tuberculosis present in the tiny droplets of saliva, and / or bronchial secretions from coughs and / or sneezing of infected people.
Tuberculosis is not spread easily. The contagion occurs following a long stay in closed environments in which there are one or more sick individuals (read the Bufala).
The home and work environment therefore represents the most common site of diffusion, especially in conditions of overcrowding, inadequate air exchange and precarious hygienic conditions. The disease is not contracted simply by sitting on a bus or train next to an infected person.
Not everyone who is sick with tuberculosis is able to spread the disease to others. Generally, extra-pulmonary tuberculosis is not transmitted by those affected.
The immune system, in most healthy people, is capable of destroying the bacterium responsible for tuberculosis. Only 10-15% of those infected develop the disease (active tuberculosis). This occurs weeks or months after the infection.
Anyone can get TB but the people most at risk are those who:
- they live in or come from areas where tuberculosis is widespread
- they have been in close contact with sick people for a long time
- they live in overcrowded environments
- have compromised immune systems, such as people with AIDS
- they are undergoing corticosteroid therapy and chemotherapy
- they use some biological drugs, as occurs in the treatment of rheumatoid arthritis
- they are very young or very old, because the immune system is weaker than that of adults
- they live without a fixed abode, and therefore they are in poor health
- use drugs
To ascertain (diagnose) tuberculosis there are tests (tests) that vary depending on the organ affected.
To diagnose the pulmonary tuberculosis A chest X-ray should be taken to highlight disease, if present. In addition, a microbiological examination of sputum both bacterioscopic (i.e. highlighting the presence of mycobacteria under a microscope) and culture (i.e. growing mycobacterium on suitable media and performing antibiotic sensitivity tests).
For the extra-pulmonary tuberculosis the exams indicated are:
- computed tomography (CT scan)
- nuclear magnetic resonance (RM)
- endoscopy and / or laparoscopy
- blood test and urinalysis
In addition, through the lumbar puncture, it is possible to analyze the fluid that bathes the brain and spinal cord (cerebro-spinal fluid) to check whether the disease has affected the central nervous system. Again it is important to perform a microbiological examination to reveal the presence of Mycobacterium tuberculosis.
Sometimes, even in the absence of the typical disorders of tuberculosis, it may be necessary to check whether an infection is in progress latent through screening tests. Latent tuberculosis can occur in people who have been in close contact with tuberculosis patients, or have lived for a long time in countries where the disease is widespread.
The Mantoux test, also called tuberculin test, is the main test to check for the presence of mycobacterium in people without disorders. It consists of injecting the tuberculin, a substance that comes from mycobacterium, under the surface layer of the skin using a syringe with a very thin needle. If infection is present, the skin is sensitive to tuberculin and within 48 to 72 hours, a fairly hard swelling develops at the injection site. If the reaction is severe, a chest X-ray is recommended to check the presence of an active infection.
If, on the other hand, the tuberculin test does not produce any effect (it is negative) it means that the body's defense system (immune system) has not come into contact with the tuberculosis bacterium.
Currently to ascertain (diagnose) the latent tuberculosis a blood test, called Interferon Gamma Release Assay (IGRA) because it is considered more specific for the Mycobacterium tuberculosis. It is carried out in the following cases:
- people with a positive response to the Mantoux test
- individuals vaccinated for tuberculosis
- people from countries where tuberculosis is widespread
- individuals to undergo treatments that weaken the immune system
- health workers
Tuberculosis is a serious disease but, if treated correctly with the right medications, it can be defeated.
The most suitable anti-tuberculosis treatment (therapy) is established by the doctor on the basis of the person's state of health and the results of the analyzes (sensitivity tests to antibiotics performed on Mycobacterium tuberculosis obtained from microbiological cultures). The drugs used are antibiotics that must be administered for a long time, from 6 to 18-24 months.
In the case of the pulmonary tuberculosis the therapy lasts 6 months and involves the administration of four antibiotics for the first 2 months (isoniazid, rifampicin, pyrazinamide and ethambutol) and then continues for 4 months with 2 antibiotics (isoniazid and rifampicin).
The first signs of improvement appear only after a few weeks or months from the start of therapy and depend on the general state of health and the severity of the disease. Once started, treatment with anti-tuberculosis drugs must be followed scrupulously in detail and must be accompanied by control tests that provide information on the progress of the disease. If you do not follow these guidelines or stop the treatment prescribed by your doctor, the tuberculosis bacterium can develop resistance to antibiotics making it more difficult and along the path to recovery.
For the care of extra-pulmonary tuberculosis the same antibiotics used for the treatment should be administered for about 12 months pulmonary tuberculosis. Furthermore, if the infection is present in the brain or in the membrane that lines the heart (pericardium), in addition to antibiotics it will be necessary to use corticosteroids in order to reduce the inflammation present.
Also in this case, the taking of the drugs must take place in a constant and regular way.
After taking anti-tuberculosis drugs, various disorders may appear such as fatigue, yellowing of the skin and mucous membranes (jaundice), tingling and numbness of the hands and feet, itching, blurred vision. In this case it is necessary to notify the attending physician immediately. .