Tuberculosis – the disease is still relevant

Proven content

Tuberculosis is still one of the most common infectious diseases in the world, despite intensive efforts to prevent and treat it. This disease does not only affect people living in poverty, but is also observed in young people who devote themselves intensively to their professional work, and thus often live under a lot of stress, eat in a hurry incomplete food or use all kinds of stimulants in excess.

Tuberculosis is classified as bacterial infectious disease as a result of infection with tuberculosis bacilli. These bacteria were discovered in the second half of the XNUMXth century by the German bacteriologist Robert Koch and are often also called Koch bacilli. It is now known that classical tuberculosis can be caused by three species of mycobacteria: Mycobacterium tuberculosis, Mycobacterium bovis (bovine mycobacterium) and Mycobacterium africanum.

Mycobacteria are extremely resistant to drying out bacteria and can survive for months in dust particles. However, they are very sensitive to ultraviolet radiation and high temperature. Cooking or pasteurization kills the tuberculosis mycobacteria quickly.

Some figures

According to data from the World Health Organization, in 2008 about 9,4 million people worldwide fell ill with tuberculosis, and about 1,3 million people died from this disease. The greatest number of cases and deaths are observed in developing countries, in particular Africa and Asia.

In Poland, a slight gradual decrease in the incidence of tuberculosis has been observed in recent years, but it is still a common disease. Based on the analyzes carried out by the Institute of Tuberculosis and Lung Diseases in Warsaw, in 2008, 8616 cases of tuberculosis were found in our country, and in relation to 2007 it was 535 less and 4098 fewer than in 1998. The highest incidence of tuberculosis was recorded in the following voivodeships: Świętokrzyskie, Lubelskie and Łódzkie. In 2007, 744 people died of tuberculosis in Poland.

Whom it concerns

Tuberculosis is referred to as a social disease because it is closely related to living conditions: malnutrition, poor housing conditions, poor sanitation, and poverty. Nevertheless, this disease does not only affect people living in poverty, but is also observed in young people who devote themselves intensively to their professional work, and thus often live under high stress, eat in a hurry, eaten or use all kinds of stimulants in excess. Another, very important group of people with a high increase in tuberculosis incidence are people infected with HIV.

How the infection occurs

The most common route of infection with mycobacterium tuberculosis is inhalation, and the main source of infection are mycobacterial patients, i.e. actively shedding mycobacteria along with the secretions from the respiratory tract. A sick mycobacterium expels mycobacteria not only during coughing, but also during expectoration, sneezing or talking. One patient with active mycobacteria can infect about 15 people a year. Mycobacterium tuberculosis with air flow enters the body through the respiratory tract during inhalation, and their carriers are sputum or saliva droplets or dust particles remaining in the air in the form of aerosols.

Another possible route of infection is via the ingestion, however, in countries with appropriate sanitary and veterinary regimes, it rarely plays a role in the transmission of mycobacterium tuberculosis. The main source of infection in the case of the digestive tract is unpasteurized milk or dairy products from cattle patients suffering from tuberculosis.

Alarming symptoms

In the initial stage of tuberculosis, the symptoms are nonspecific and the disease development is poorly expressed. Symptoms may be general, resulting from our body’s reaction to infections, and may be specific to the affected organ. Due to the fact that the lungs are most often attacked, the symptoms of the lower respiratory tract are dominant.

Symptoms such as:

1. a cough that lasts for at least 3 weeks, initially dry and then moist, producing mucus or purulent discharge,
2. blood plucking,
3. dyspnoea,
4. pain in the chest,
5. fever or low-grade fever,
6. night sweats
7. weight loss
8. weakness and easy fatigue with little effort.

The above symptoms may also appear in other lung diseases, but their diagnosis always requires a diagnosis for tuberculosis.

The face of the disease

The fact of infection with tuberculosis bacilli is not synonymous with the development of tuberculosis. Only 3-8 percent. people infected with mycobacteria develop the disease. In most infected mycobacteria, after entering the body, they are eliminated by the immune system or remain dormant without causing disease symptoms. Unfortunately, an infected person is at risk of developing tuberculosis throughout their lives. The main factor causing the transition of mycobacteria from dormancy to active state, as a result of the development of the disease, is the decrease in immunity. The lack of control of the immune system allows for the intensive multiplication and spread of mycobacteria in the human body. Mycobacteria attack all organs and systems of our body, causing pathological changes in them, and due to the fact that the primary route of infection is inhalation, the primary changes concern the lungs. The basic risk factors that lower immune immunity include: HIV infection, malnutrition, cancer, diabetes, kidney failure, liver disease, alcoholism, drug addiction, and immunosuppressive treatment.

The classic breakdown of tuberculosis is:

1. primary tuberculosis – develops as a result of the first-time infection with mycobacteria and most often affects the lungs,
2. post-primary tuberculosis – is the result of reactivation of primary tuberculosis after several months or years and may affect the lungs as well as other organs,

Taking into account the place where the disease develops, we distinguish:

1. pulmonary tuberculosis,
2. extrapulmonary tuberculosis, including:
3. tuberculosis of the lymph nodes – mainly in children and young adults,
4. pleural tuberculosis,
5. tuberculosis of the genitourinary system – is secret and may lead to renal failure,
6. tuberculosis of the central nervous system,
7. tuberculosis of bones and joints – mainly in the elderly; the first symptom may be a spontaneous fracture of, for example, the spine
8. tuberculosis of the digestive system – it occurs rarely,
9. skin tuberculosis – very rare.

Untreated tuberculosis leads to the gradual destruction of the body and ultimately to the failure of the organ in which the disease process takes place. The main cause of death in tuberculosis is respiratory failure.

What tests will confirm the disease

The best way to diagnose tuberculosis is microbiological diagnostics, i.e. growing mycobacteria from materials collected from the patient. The basic materials include: sputum, bronchial secretions collected during bronchoscopy, urine for tuberculosis of the genitourinary organs, and gastric lavage collected on an empty stomach, which are the basic material for suspected pulmonary tuberculosis in children. Microbiological diagnostics is based on the cultivation of mycobacteria, their identification and determination of susceptibility to anti-mycobacterial drugs. Unfortunately, the main disadvantage of classical breeding is the very long growth of bacteria and the result is obtained only after 3-6 weeks. In order to accelerate the diagnosis, genetic methods are used more and more often in diagnostics – the use of specific probes for mycobacterium tuberculosis. The result is known on the same day.

Additionally, the diagnosis of tuberculosis uses:

– X-rays – chest X-rays – specific changes in the lungs

– tuberculin reaction – intradermal injection of tuberculin into the dorsal surface of the forearm; the diameter of the infiltration is read after 48-72 hours; a positive result is an infiltrate with a diameter of more than 10 mm; the disadvantage of the tuberculin test is that it does not differentiate between infection and disease.

What is the treatment

Correct antituberculosis treatment leads to full recovery. In the treatment of tuberculosis, chemotherapeutic agents are used, which are divided into:

– first-line drugs: isoniazid, rifampicin, ethambutol, streptomycin, pyrazinamide,

– second-choice drugs (alternative): ethionamide, capreomycin, cycloserine, kanamycin, fluoroquinolones and others.

In the initial phase of tuberculosis treatment, 3 or 4 drugs are used, depending on the scheme, and then in the stabilization phase 2 drugs, most often isoniazid with rifampicin. Treatment duration is 6 to 9 months, depending on the form of tuberculosis.

The condition for achieving therapeutic success is the proper cooperation of the patient with the medical staff during the entire treatment and it boils down to:

– taking all antituberculosis drugs at the same time,

– taking drugs in recommended doses,

– taking medication for as long as required by the treatment regimen.

In addition, direct supervised treatment, i.e. taking medications in the presence of a nurse or volunteer, guarantees compliance with all the principles of anti-tuberculosis therapy. In the first stage of tuberculosis treatment, hospital treatment is recommended to reduce the risk of infection to other people during the mycobacterial period and to observe the patient for side effects of antituberculosis drugs. After 2-3 weeks of proper anti-tuberculosis treatment, the patient no longer produces mycobacteria. The average length of stay in hospital is 4-6 weeks. After disinfection, the patient may continue further treatment under supervision in a local outpatient clinic. Additionally, to strengthen the immune system, it is advisable to follow a high-calorie diet, rest, quit smoking and stop drinking alcohol.

What preventive measures

The basic step in limiting the spread of tuberculosis is early diagnosis and treatment of the disease. Each person who has had contact with a tuberculosis patient, especially with tuberculosis, should be tested to exclude this disease (observation for symptoms, tuberculin test, chest X-ray).

Another preventive measure is the use of chemoprophylaxis by treatment with isoniazid for 6 to 12 months, and is recommended only for HIV-infected people and for young children who are in contact with tuberculosis patients.

Prophylactic measures also include vaccination against tuberculosis, which does not protect against infection, but reduces the severity of the disease. In Poland, according to the vaccination schedule, newborns are obligatorily vaccinated within 24 hours after birth. Booster doses are no longer routinely used today.

Preventive actions also include drawing the attention of tuberculosis patients to covering their mouth and nose when coughing or sneezing, and to coughing up secretions into a tissue or a pocket spittoon bowl.

The last very important step in preventing tuberculosis is reducing the spread of HIV infection and improving living conditions, in particular fighting poverty and hunger in the world.

Current threats

It can be said with high probability that it will not be possible to completely eliminate tuberculosis in the world. According to many experts, there is a risk of a large increase in the incidence of tuberculosis again and an increase in mortality from this disease. A very disturbing phenomenon is the appearance of multi-drug-resistant tuberculosis: MDR-TB (multi-drug – resistant tuberculosis) – simultaneous resistance of mycobacteria to two basic drugs: isoniazid and rifampicin, and the XD-TB (extensively drug-resistant tuberculosis) variety – mycobacterial resistance to what at least four drugs. The phenomenon of mycobacterial resistance is the result of errors in tuberculosis treatment, in particular, not using appropriate regimens and too short unsystematic treatment. In 2007, almost half a million cases of multi-drug resistant tuberculosis were found worldwide, and India and China (almost 50% of patients) have the biggest problems with this type of tuberculosis. Treatment of multi-drug resistant TB is difficult, long and very expensive.

Mirosław Jawień, MD, PhD – Department of Infection Epidemiology, Department of Microbiology, Collegium Medicum of the Jagiellonian University