pneumonia mode of transmission

Pneumonia refers to inflammation of terminal airway, alveoli and lung interstitium, which can be caused by pathogenic microorganisms, physical and chemical factors, immune damage, allergy and drugs. According to anatomical classification, it can be divided into lobar pneumonia, lobular pneumonia and interstitial pneumonia; according to etiological classification, it can be divided into bacterial pneumonia, pneumonia caused by atypical pathogens, pathogenic pneumonia and pulmonary fungal disease; pneumonia caused by other causes, pneumonia caused by physical and chemical factors, etc. The main routes of infection are air inhalation, hematogenous dissemination, direct spread adjacent to the site of infection, and inhalation of upper respiratory tract colonization bacteria.