Pulmonary tuberculosis

Pulmonary tuberculosis is a chronic lung infection caused by Mycobacterium tuberculosis, with its main clinical features being cough, chest pain, hemoptysis, evening fever, night sweats, weight loss, and elevated erythrocyte sedimentation rate. Mycobacterium tuberculosis belongs to the genus Mycobacterium and exhibits acid-fast staining properties, hence it is also called acid-fast bacillus. There are two types that can cause human tuberculosis: human-type and bovine-type Mycobacterium tuberculosis, with the human type being predominant. Tubercle bacilli are excreted through respiratory secretions from patients or carriers and are dispersed into the air with dust to infect others, especially in patients with open pulmonary tuberculosis, whose sputum is the primary source of transmission. Additionally, coughing and sneezing can also contaminate the air. Whether the disease develops is closely related to the body's immune status. Patients with pulmonary tuberculosis often present with cough, sputum production, hemoptysis, chest pain, dyspnea, fever (mostly afternoon evening fever), fatigue and weakness, night sweats, decreased appetite, and weight loss. Dullness on percussion over the supraclavicular and infrascapular regions, fine moist rales on auscultation, positive tuberculin test, and positive sputum culture for Mycobacterium tuberculosis indicate active tuberculosis. First-line drugs are the preferred choice for initial treatment cases, including isoniazid and rifampicin, which have the advantages of strong anti-tuberculosis activity, good efficacy, low toxicity, and convenient use. Second-line anti-tuberculosis drugs include ethionamide, kanamycin, and capreomycin, mainly used for patients whose bacteria have developed resistance to first-line drugs and for retreatment cases after failed initial treatment; these drugs have more toxic reactions. Prevention of this disease mainly depends on the strength of the constitution, the severity of the illness, and the timeliness of treatment. Early treatment is particularly important; if detected and treated early, the prognosis is generally good. If treatment is delayed and the disease lingers, with pronounced systemic debilitation, the prognosis is generally poor.