Respiratory tuberculosis

Description of Tuberculosis

It is a chronic bacterial infection, most commonly affecting the lungs.

Causative Agent

Tuberculosis is caused by the bacteria Mycobacterium tuberculosis, less commonly Mycobacterium bovis and Mycobacterium africanum. They are highly resistant, persist for a long time under various conditions, not afraid of cold. Tuberculosis bacteria can survive and cause the disease for about six months in liquid sputum, and can last for several months in contaminated soft objects, water, and on walls. They die when exposed to direct sunlight, dry heat, or boiling.

Prevalence

Every year, more than 8 million people are actively infected with tuberculosis, and about 2 million die. The source of infection is a person with open pulmonary tuberculosis, whose sputum contains tuberculosis mycobacteria. The infection is usually transmitted through droplets in the air, and alimentary transmission is also possible. Mycobacteria enter the environment when coughing, sneezing, laughing. Eating unpasteurized milk or its products from infected animals, raw meat, first affects the intestines or tonsils. Factors increasing the risk of tuberculosis include: low mood, unsatisfactory social and work conditions, positive Mantoux tests, HIV infection and AIDS, use of corticosteroids, immunosuppressive therapy, smoking, diabetes, lung diseases such as pulmonary inflammation.

Symptoms

Individuals with tuberculosis rarely express complaints. Common symptoms of the disease include: weakness, fatigue, disturbed sleep, weight loss, low-grade fever, sweating, especially at night. Respiratory involvement manifests as a cough, prolonged for more than 3 weeks, coughing up blood, shortness of breath, sometimes chest pain. Lymph nodes in the neck, armpits, and other areas often enlarge in patients.

Diagnosis

Tuberculosis is diagnosed by performing bacteriological tests to identify the causative agent. This includes culturing sputum, pleural punctures, urine, and other secretions, as well as microscopic examination of sputum. Radiological diagnostics (X-ray, radiography, computed tomography) are important in identifying the cause of lung damage. Bronchoscopy and video-assisted thoracoscopy are also used. Tuberculin (Mantoux) test is used for tuberculosis diagnosis, especially in children. Acute infection is indicated by changes in blood: increased white blood cells, eosinophils, decreased lymphocyte count, slightly increased erythrocyte sedimentation rate.

Treatment

Long-term treatment lasts from 6 months (if the causative agent is sensitive to drugs) to 24 months (if there is multidrug resistance). First-line drugs for tuberculosis are isoniazid, pyrazinamide, rifampicin, streptomycin, and ethambutol. Second-line drugs include thioamides and quinolones. Reserve drugs include macrolides, clofazimine, rifabutin, ampicillin or amoxicillin with clavulanic acid.

Prevention

The most important aspect is to identify those infected early and actively treat them. It is necessary to disinfect rooms, belongings of the patient, spittoons, and educate the patient and their close contacts.

Source | Author Doctor Nikas Samuolis, reviewed by Prof. Virginijus Šapoka | Vilnius University | Faculty of Medicine | Head of the Department of Internal Medicine, Family Medicine, and Oncology